Dwenda Gjerdingen, MD

The birth of a first child is a time of major transition for a couple, marked by significant changes in the roles and responsibilities of both parents. The nature of their responsibilities change, and the volume of their work increases markedly. Comparative data from a national longitudinal study indicate that adults of childbearing age (25-44 years) invest more combined total work hours into the home and workplace than other adults, with workloads of 82 to 84 hours per week for employed women and 70 to 71 hours per week for employed men compared with less than 67 and 61 hours per week for older women and men, respectively.¹ The way partners respond to these workload issues can have an impact on marital happiness, as shown by several studies demonstrating an association between wives’ marital satisfaction and their husbands’ participation in household work.^2-7 The sharing of work responsibility is particularly important in the first few months after childbirth, with research demonstrating a significant association between the mother’s mental health and the degree of her partner’s emotional and practical support.⁸ However, many new mothers perceive a decline in their husbands’ participation in household chores and expressions of caring over the first postpartum year.⁹

Is this move to a more traditional division of labor intentional? Would it persist if couples were given the opportunity to learn about and plan for their postpartum responsibilities? Would a more equitable division of family and household work enhance the mental and physical health of women and men and increase their marital happiness in these early childbearing years? These questions form the basis of this research in postpartum health and family systems and are particularly relevant to family physicians who work within a broad definition of health that considers the context of community and family. Though it is common for family physicians to refer expectant parents to prenatal classes on childbirth and infant care, couples typically have few or no opportunities to formally prepare themselves for their postpartum lifestyle changes, including their new and increasing work responsibilities. Parenting classes address the needs of the child and the parent-child relationship¹⁰ while couples’ groups look at partners’ communication and conflict management,¹¹ but few structured opportunities exist for couples to plan for family and household work needs after their child is born.

There were 3 goals for this study: (1) describe the work patterns of a group of employed couples living together and expecting their first child; (2) provide a formal opportunity for couples to establish a plan for sharing postpartum work; and (3) evaluate gender differences in anticipated changes in workload from before to after childbirth. Of special interest was learning how couples intended to share postpartum work responsibilities (eg, equally vs unequally) when given a formal opportunity to actively plan for postpartum work distribution. This descriptive study represents the initial phase of a randomized controlled trial testing the impact of a prenatal work planning session (conducted in the context of childbirth education classes) on the partners’ postpartum work distribution, selected mental and physical health outcomes, and marital satisfaction.

Methods

English-speaking couples living together and expecting their first child were eligible for this study. Participants were recruited from prenatal classes offered through 2 St. Paul HealthEast hospitals from November 1998 through August 1999. Research assistants visited 30 of 34 HealthEast prenatal classes during the third class session to describe the study, enroll participants, and distribute prenatal surveys. Potential subjects were told that couples randomized to the intervention would attend 2 breakout sessions that would address emotional and practical support around the time of childbirth. Data for this study were derived from prenatal surveys and from worksheets indicating partners’ anticipated postpartum work time commitments.

The prenatal survey completed independently by all subjects during the third prenatal class session was used to gather demographic data (age, sex, education, race, marital status, and employment status); information on work responsibilities, including the number of hours per week devoted to employment and various household chores; perceptions of equity of household responsibilities among partners (measured on a 1 to 7 scale where 1=partner does everything, 4=we share equally, and 7=I do everything); and satisfaction with the partner’s contribution to household responsibilities (1=very dissatisfied and 7=very satisfied).

Approximately half of the enrolled couples were then randomized to the intervention, which consisted of 2 30-minute breakout sessions held during the fourth and fifth prenatal classes. In the first session partners were asked to tell each other what the other person did to make them feel loved and cared for. During the second breakout session each couple completed a worksheet together that asked them to list the amount of time each partner planned to spend at 6 months postpartum doing various tasks, caring for their child, and participating in paid employment. Suggested time estimates for the work tasks (in hours per week) were provided (Table 1) based on the results of a previous pilot study that asked first-time parents to estimate their actual workloads at 6 months postpartum. Parents were also asked to indicate any time contributed to these areas by outside sources (eg, babysitter, daycare provider, relative, housekeeper).

Student t tests were used to investigate gender differences in the amount of time invested in work prenatally, perceived degree of sharing household tasks with the partner, satisfaction with the partner’s contribution to household work, and projected prenatal to postpartum work changes. Paired t tests were used to examine subjects’ anticipated prenatal to postpartum changes in workload. Congruency in partners’ perceptions about how they currently share household responsibilities was determined by summing their responses to the question, “Please circle the number that best describes how you and your partner currently share household responsibilities.” Responses were given on a 1 to 7 scale where 1=“partner does everything,” 4=“We share equally,” and 7=“I do everything.” Thus, a summed score of 8 indicated perfect congruency.

Results

Of the 722 expectant parents informed of the study, 76 were ineligible to participate (usually because they were not living with a partner), 346 refused to participate (the most common reason for refusal was concern about leaving the large classroom for a breakout session), and 300 (149 men and 151 women) agreed to participate, for a response rate of 46% (300/646). The mean age of the participants was 29.3 years (standard deviation=4.6); 93.3% were white; 88.6% were married; 97.9% were employed; and 62% had a 4-year college or advanced degree. A total of 132 people (66 men and 66 women) participated in the breakout sessions.

The amount of time expectant fathers and mothers devoted to various household tasks and employment prenatally is shown in Table 1. Although men and women contributed similar amounts of time to household work—18.2 and 20.0 hours, respectively—they tended to divide these tasks according to traditional work patterns, with men investing more time in household repairs, lawn care, and snow removal, and women spending more time with cooking, cleaning, laundry, and shopping. Compared with women, men worked longer hours at their jobs, and this resulted in a heavier mean total prenatal workload for men by 8.4 hours per week (P=.000).

In response to the question of how they shared household responsibilities, women reported a belief that they contributed more to household chores than their partners (mean=4.4 and 3.8 for women and men, respectively; P=.000). This finding is consistent with women’s slightly higher estimated contributions to household tasks (P=NS). Partners’ perceptions about how they shared household work were congruent: 90% of couples had summed congruency scores in the 7 to 9 range, which allows for no more than a 1-point deviation from a perfect summed congruency score of 8. On average men were more satisfied than women with their partner’s contribution to household work (mean=6.0 and 5.4 for men and women, respectively; P=.000). The projected prenatal to postpartum changes in workload were considerable for both men and women (Table 2). Women predicted an 85% increase, and men anticipated a 53% expansion of total workload, with a net result of women planning to work 9 hours per week more than men at 6 months postpartum (P <.001). Both men and women predicted significant increases in time spent on household tasks, child care, and total work; the projected changes in effort related to child care and total work were significantly greater for women than men (P=.000), as shown in Table 3. Both men and women planned to reduce their paid work commitments after childbirth, women to a greater degree than men (P=.000).

Discussion

The results indicate that while men shouldered heavier workloads prenatally, women anticipated working longer hours than men at 6 months postpartum by 9 hours per week. This amounts to an 85% (48.7 hours/week) increase in workload for women, compared with a 53% (33.3 hours/week) increase for men. Although both are astounding increases, women clearly anticipated a larger expansion of work than men. Such dramatic changes in work responsibilities realized by new mothers might be at least partially responsible for the mental and physical problems that often plague women after childbirth.^8,12

The projected postpartum difference in workload between men and women was not unexpected, given the findings of Kahn¹ that on average, adult women of all ages in the United States bear heavier total workloads than men. It is noteworthy, however, that this gender difference in workloads was anticipated even by a group of couples who had had an opportunity to systematically study and preplan their postpartum work distribution.

It appears that to some degree these planned gender discrepancies in postpartum work responsibilities might be explained on the basis of traditional sex role assumptions. Women planned to take on more of the child care and household responsibilities after childbirth than men: 79 versus 52 hours per week. To help compensate for this considerable expansion of unpaid work, expectant mothers also planned to trim an average of 11.7 hours per week from their paid jobs compared with expectant fathers’ anticipated drop of 2.2 hours per week. For many women this change would likely result in part-time work. Previous studies have documented that both men and women tend to work part-time more in the childbearing years than at any other time in their adult lives, and women’s use of part-time work hours during this period of life tends to be much greater than men’s, often 2 to 3 times more.¹³ These data reinforce the need for couples to consider many complex issues in their postpartum workload planning, such as whether their dissimilar reductions in paid work will have a differential impact on their career satisfaction and opportunities and whether their joint plans for curtailing employment hours could ultimately benefit the family unit by improving child and family development.

Although expectant fathers and mothers in this study tended to follow traditional patterns in their qualitative division of various household responsibilities, they devoted similar amounts of total time to household tasks (18.2 and 20.0 hours/week, respectively). This finding contrasts with that of previous studies showing a much greater share of household work being performed by women,^1,14,15 often twice as much or more.^1,14,16 The results could be related to several factors. First, the observed prenatal work patterns may be somewhat atypical for these couples: Several women indicated that they had cut back on their housework or employment hours because of pregnancy-associated fatigue or other health problems. Second, this was a very homogenous population of employed young couples without children, in contrast to the more diverse samples (which included adults with children and more unemployed wives) used in many previous studies. Alternatively, these findings might represent a societal trend toward men and women sharing housework more equitably.

Importantly for many of these parents, the changes in work that they anticipated after giving birth likely represent the largest and most abrupt increase in work responsibilities that they will face in their adult lives. Unfortunately, it is a change for which many parents are ill-prepared. This lack of preparation is likely due, at least in part, to the paucity of information available on new parents’ actual workloads (no specific information was found in the medical, sociological, and psychological searches), society’s tendency to focus on the health needs of newborns and children more than those of their parents, and the absence of a consistent method for educating adolescents and young adults about the responsibilities of supporting and nurturing a family.

Each of these needs will be addressed. First, additional research is needed on changes in work responsibilities for new parents from more diverse populations, and we need a greater understanding of how these work responsibilities affect health and marital well-being (the goal of the ongoing randomized controlled trial). Second, we need a broader view of postpartum care, such that the physical, mental, and social needs of both the parents and newborn are considered in an ongoing manner. This is a perspective that family physicians are uniquely positioned to adopt and foster within the context of prenatal and postpartum care for the family unit. Moreover, family physicians could also be part of the solution to the third need, that of teaching would-be parents about postpartum work and family responsibilities. These efforts may pay important dividends in strengthening the fiber of the family and improving the well-being of its individual members.

Limitations

The limitations of this study include the modest response rate, the potential for selection bias, and the relatively homogeneous sample. In addition, parents’ estimations of work time may not be completely accurate, and these simple estimations do not account for such factors as the intensity of work at any given time (as when one juggles numerous responsibilities concurrently) or the issue of who holds the ultimate responsibility for a given task. Though future workload projections may be even more inaccurate than current estimations, the results shown here are more than individuals’ guesses about their future work; they represent couples’ intentional plans for sharing postpartum work responsibilities.

Conclusions

These expectant first-time parents anticipated considerable expansions in their work activities after childbirth, with women planning a greater share of the total postpartum workload. This information is important for new parents and for the health care providers who attend them as they resume their household, family, and paid work responsibilities after childbirth.

Acknowledgments

This study was funded by the University of Minnesota graduate school.

The author would like to thank Anne Marie Weber-Main for her editing assistance and Bruce Center for his help with data analysis.

The birth of a first child is a time of major transition for a couple, marked by significant changes in the roles and responsibilities of both parents. The nature of their responsibilities change, and the volume of their work increases markedly. Comparative data from a national longitudinal study indicate that adults of childbearing age (25-44 years) invest more combined total work hours into the home and workplace than other adults, with workloads of 82 to 84 hours per week for employed women and 70 to 71 hours per week for employed men compared with less than 67 and 61 hours per week for older women and men, respectively.¹ The way partners respond to these workload issues can have an impact on marital happiness, as shown by several studies demonstrating an association between wives’ marital satisfaction and their husbands’ participation in household work.^2-7 The sharing of work responsibility is particularly important in the first few months after childbirth, with research demonstrating a significant association between the mother’s mental health and the degree of her partner’s emotional and practical support.⁸ However, many new mothers perceive a decline in their husbands’ participation in household chores and expressions of caring over the first postpartum year.⁹

Is this move to a more traditional division of labor intentional? Would it persist if couples were given the opportunity to learn about and plan for their postpartum responsibilities? Would a more equitable division of family and household work enhance the mental and physical health of women and men and increase their marital happiness in these early childbearing years? These questions form the basis of this research in postpartum health and family systems and are particularly relevant to family physicians who work within a broad definition of health that considers the context of community and family. Though it is common for family physicians to refer expectant parents to prenatal classes on childbirth and infant care, couples typically have few or no opportunities to formally prepare themselves for their postpartum lifestyle changes, including their new and increasing work responsibilities. Parenting classes address the needs of the child and the parent-child relationship¹⁰ while couples’ groups look at partners’ communication and conflict management,¹¹ but few structured opportunities exist for couples to plan for family and household work needs after their child is born.

There were 3 goals for this study: (1) describe the work patterns of a group of employed couples living together and expecting their first child; (2) provide a formal opportunity for couples to establish a plan for sharing postpartum work; and (3) evaluate gender differences in anticipated changes in workload from before to after childbirth. Of special interest was learning how couples intended to share postpartum work responsibilities (eg, equally vs unequally) when given a formal opportunity to actively plan for postpartum work distribution. This descriptive study represents the initial phase of a randomized controlled trial testing the impact of a prenatal work planning session (conducted in the context of childbirth education classes) on the partners’ postpartum work distribution, selected mental and physical health outcomes, and marital satisfaction.

Methods

English-speaking couples living together and expecting their first child were eligible for this study. Participants were recruited from prenatal classes offered through 2 St. Paul HealthEast hospitals from November 1998 through August 1999. Research assistants visited 30 of 34 HealthEast prenatal classes during the third class session to describe the study, enroll participants, and distribute prenatal surveys. Potential subjects were told that couples randomized to the intervention would attend 2 breakout sessions that would address emotional and practical support around the time of childbirth. Data for this study were derived from prenatal surveys and from worksheets indicating partners’ anticipated postpartum work time commitments.

The prenatal survey completed independently by all subjects during the third prenatal class session was used to gather demographic data (age, sex, education, race, marital status, and employment status); information on work responsibilities, including the number of hours per week devoted to employment and various household chores; perceptions of equity of household responsibilities among partners (measured on a 1 to 7 scale where 1=partner does everything, 4=we share equally, and 7=I do everything); and satisfaction with the partner’s contribution to household responsibilities (1=very dissatisfied and 7=very satisfied).

Approximately half of the enrolled couples were then randomized to the intervention, which consisted of 2 30-minute breakout sessions held during the fourth and fifth prenatal classes. In the first session partners were asked to tell each other what the other person did to make them feel loved and cared for. During the second breakout session each couple completed a worksheet together that asked them to list the amount of time each partner planned to spend at 6 months postpartum doing various tasks, caring for their child, and participating in paid employment. Suggested time estimates for the work tasks (in hours per week) were provided (Table 1) based on the results of a previous pilot study that asked first-time parents to estimate their actual workloads at 6 months postpartum. Parents were also asked to indicate any time contributed to these areas by outside sources (eg, babysitter, daycare provider, relative, housekeeper).

Student t tests were used to investigate gender differences in the amount of time invested in work prenatally, perceived degree of sharing household tasks with the partner, satisfaction with the partner’s contribution to household work, and projected prenatal to postpartum work changes. Paired t tests were used to examine subjects’ anticipated prenatal to postpartum changes in workload. Congruency in partners’ perceptions about how they currently share household responsibilities was determined by summing their responses to the question, “Please circle the number that best describes how you and your partner currently share household responsibilities.” Responses were given on a 1 to 7 scale where 1=“partner does everything,” 4=“We share equally,” and 7=“I do everything.” Thus, a summed score of 8 indicated perfect congruency.

Results

Of the 722 expectant parents informed of the study, 76 were ineligible to participate (usually because they were not living with a partner), 346 refused to participate (the most common reason for refusal was concern about leaving the large classroom for a breakout session), and 300 (149 men and 151 women) agreed to participate, for a response rate of 46% (300/646). The mean age of the participants was 29.3 years (standard deviation=4.6); 93.3% were white; 88.6% were married; 97.9% were employed; and 62% had a 4-year college or advanced degree. A total of 132 people (66 men and 66 women) participated in the breakout sessions.

The amount of time expectant fathers and mothers devoted to various household tasks and employment prenatally is shown in Table 1. Although men and women contributed similar amounts of time to household work—18.2 and 20.0 hours, respectively—they tended to divide these tasks according to traditional work patterns, with men investing more time in household repairs, lawn care, and snow removal, and women spending more time with cooking, cleaning, laundry, and shopping. Compared with women, men worked longer hours at their jobs, and this resulted in a heavier mean total prenatal workload for men by 8.4 hours per week (P=.000).

In response to the question of how they shared household responsibilities, women reported a belief that they contributed more to household chores than their partners (mean=4.4 and 3.8 for women and men, respectively; P=.000). This finding is consistent with women’s slightly higher estimated contributions to household tasks (P=NS). Partners’ perceptions about how they shared household work were congruent: 90% of couples had summed congruency scores in the 7 to 9 range, which allows for no more than a 1-point deviation from a perfect summed congruency score of 8. On average men were more satisfied than women with their partner’s contribution to household work (mean=6.0 and 5.4 for men and women, respectively; P=.000). The projected prenatal to postpartum changes in workload were considerable for both men and women (Table 2). Women predicted an 85% increase, and men anticipated a 53% expansion of total workload, with a net result of women planning to work 9 hours per week more than men at 6 months postpartum (P <.001). Both men and women predicted significant increases in time spent on household tasks, child care, and total work; the projected changes in effort related to child care and total work were significantly greater for women than men (P=.000), as shown in Table 3. Both men and women planned to reduce their paid work commitments after childbirth, women to a greater degree than men (P=.000).

Discussion

The results indicate that while men shouldered heavier workloads prenatally, women anticipated working longer hours than men at 6 months postpartum by 9 hours per week. This amounts to an 85% (48.7 hours/week) increase in workload for women, compared with a 53% (33.3 hours/week) increase for men. Although both are astounding increases, women clearly anticipated a larger expansion of work than men. Such dramatic changes in work responsibilities realized by new mothers might be at least partially responsible for the mental and physical problems that often plague women after childbirth.^8,12

The projected postpartum difference in workload between men and women was not unexpected, given the findings of Kahn¹ that on average, adult women of all ages in the United States bear heavier total workloads than men. It is noteworthy, however, that this gender difference in workloads was anticipated even by a group of couples who had had an opportunity to systematically study and preplan their postpartum work distribution.

It appears that to some degree these planned gender discrepancies in postpartum work responsibilities might be explained on the basis of traditional sex role assumptions. Women planned to take on more of the child care and household responsibilities after childbirth than men: 79 versus 52 hours per week. To help compensate for this considerable expansion of unpaid work, expectant mothers also planned to trim an average of 11.7 hours per week from their paid jobs compared with expectant fathers’ anticipated drop of 2.2 hours per week. For many women this change would likely result in part-time work. Previous studies have documented that both men and women tend to work part-time more in the childbearing years than at any other time in their adult lives, and women’s use of part-time work hours during this period of life tends to be much greater than men’s, often 2 to 3 times more.¹³ These data reinforce the need for couples to consider many complex issues in their postpartum workload planning, such as whether their dissimilar reductions in paid work will have a differential impact on their career satisfaction and opportunities and whether their joint plans for curtailing employment hours could ultimately benefit the family unit by improving child and family development.

Although expectant fathers and mothers in this study tended to follow traditional patterns in their qualitative division of various household responsibilities, they devoted similar amounts of total time to household tasks (18.2 and 20.0 hours/week, respectively). This finding contrasts with that of previous studies showing a much greater share of household work being performed by women,^1,14,15 often twice as much or more.^1,14,16 The results could be related to several factors. First, the observed prenatal work patterns may be somewhat atypical for these couples: Several women indicated that they had cut back on their housework or employment hours because of pregnancy-associated fatigue or other health problems. Second, this was a very homogenous population of employed young couples without children, in contrast to the more diverse samples (which included adults with children and more unemployed wives) used in many previous studies. Alternatively, these findings might represent a societal trend toward men and women sharing housework more equitably.

Importantly for many of these parents, the changes in work that they anticipated after giving birth likely represent the largest and most abrupt increase in work responsibilities that they will face in their adult lives. Unfortunately, it is a change for which many parents are ill-prepared. This lack of preparation is likely due, at least in part, to the paucity of information available on new parents’ actual workloads (no specific information was found in the medical, sociological, and psychological searches), society’s tendency to focus on the health needs of newborns and children more than those of their parents, and the absence of a consistent method for educating adolescents and young adults about the responsibilities of supporting and nurturing a family.

Each of these needs will be addressed. First, additional research is needed on changes in work responsibilities for new parents from more diverse populations, and we need a greater understanding of how these work responsibilities affect health and marital well-being (the goal of the ongoing randomized controlled trial). Second, we need a broader view of postpartum care, such that the physical, mental, and social needs of both the parents and newborn are considered in an ongoing manner. This is a perspective that family physicians are uniquely positioned to adopt and foster within the context of prenatal and postpartum care for the family unit. Moreover, family physicians could also be part of the solution to the third need, that of teaching would-be parents about postpartum work and family responsibilities. These efforts may pay important dividends in strengthening the fiber of the family and improving the well-being of its individual members.

Limitations

The limitations of this study include the modest response rate, the potential for selection bias, and the relatively homogeneous sample. In addition, parents’ estimations of work time may not be completely accurate, and these simple estimations do not account for such factors as the intensity of work at any given time (as when one juggles numerous responsibilities concurrently) or the issue of who holds the ultimate responsibility for a given task. Though future workload projections may be even more inaccurate than current estimations, the results shown here are more than individuals’ guesses about their future work; they represent couples’ intentional plans for sharing postpartum work responsibilities.

Conclusions

These expectant first-time parents anticipated considerable expansions in their work activities after childbirth, with women planning a greater share of the total postpartum workload. This information is important for new parents and for the health care providers who attend them as they resume their household, family, and paid work responsibilities after childbirth.

Acknowledgments

This study was funded by the University of Minnesota graduate school.

The author would like to thank Anne Marie Weber-Main for her editing assistance and Bruce Center for his help with data analysis.

The birth of a first child is a time of major transition for a couple, marked by significant changes in the roles and responsibilities of both parents. The nature of their responsibilities change, and the volume of their work increases markedly. Comparative data from a national longitudinal study indicate that adults of childbearing age (25-44 years) invest more combined total work hours into the home and workplace than other adults, with workloads of 82 to 84 hours per week for employed women and 70 to 71 hours per week for employed men compared with less than 67 and 61 hours per week for older women and men, respectively.¹ The way partners respond to these workload issues can have an impact on marital happiness, as shown by several studies demonstrating an association between wives’ marital satisfaction and their husbands’ participation in household work.^2-7 The sharing of work responsibility is particularly important in the first few months after childbirth, with research demonstrating a significant association between the mother’s mental health and the degree of her partner’s emotional and practical support.⁸ However, many new mothers perceive a decline in their husbands’ participation in household chores and expressions of caring over the first postpartum year.⁹

Is this move to a more traditional division of labor intentional? Would it persist if couples were given the opportunity to learn about and plan for their postpartum responsibilities? Would a more equitable division of family and household work enhance the mental and physical health of women and men and increase their marital happiness in these early childbearing years? These questions form the basis of this research in postpartum health and family systems and are particularly relevant to family physicians who work within a broad definition of health that considers the context of community and family. Though it is common for family physicians to refer expectant parents to prenatal classes on childbirth and infant care, couples typically have few or no opportunities to formally prepare themselves for their postpartum lifestyle changes, including their new and increasing work responsibilities. Parenting classes address the needs of the child and the parent-child relationship¹⁰ while couples’ groups look at partners’ communication and conflict management,¹¹ but few structured opportunities exist for couples to plan for family and household work needs after their child is born.

There were 3 goals for this study: (1) describe the work patterns of a group of employed couples living together and expecting their first child; (2) provide a formal opportunity for couples to establish a plan for sharing postpartum work; and (3) evaluate gender differences in anticipated changes in workload from before to after childbirth. Of special interest was learning how couples intended to share postpartum work responsibilities (eg, equally vs unequally) when given a formal opportunity to actively plan for postpartum work distribution. This descriptive study represents the initial phase of a randomized controlled trial testing the impact of a prenatal work planning session (conducted in the context of childbirth education classes) on the partners’ postpartum work distribution, selected mental and physical health outcomes, and marital satisfaction.

Methods

English-speaking couples living together and expecting their first child were eligible for this study. Participants were recruited from prenatal classes offered through 2 St. Paul HealthEast hospitals from November 1998 through August 1999. Research assistants visited 30 of 34 HealthEast prenatal classes during the third class session to describe the study, enroll participants, and distribute prenatal surveys. Potential subjects were told that couples randomized to the intervention would attend 2 breakout sessions that would address emotional and practical support around the time of childbirth. Data for this study were derived from prenatal surveys and from worksheets indicating partners’ anticipated postpartum work time commitments.

The prenatal survey completed independently by all subjects during the third prenatal class session was used to gather demographic data (age, sex, education, race, marital status, and employment status); information on work responsibilities, including the number of hours per week devoted to employment and various household chores; perceptions of equity of household responsibilities among partners (measured on a 1 to 7 scale where 1=partner does everything, 4=we share equally, and 7=I do everything); and satisfaction with the partner’s contribution to household responsibilities (1=very dissatisfied and 7=very satisfied).

Approximately half of the enrolled couples were then randomized to the intervention, which consisted of 2 30-minute breakout sessions held during the fourth and fifth prenatal classes. In the first session partners were asked to tell each other what the other person did to make them feel loved and cared for. During the second breakout session each couple completed a worksheet together that asked them to list the amount of time each partner planned to spend at 6 months postpartum doing various tasks, caring for their child, and participating in paid employment. Suggested time estimates for the work tasks (in hours per week) were provided (Table 1) based on the results of a previous pilot study that asked first-time parents to estimate their actual workloads at 6 months postpartum. Parents were also asked to indicate any time contributed to these areas by outside sources (eg, babysitter, daycare provider, relative, housekeeper).

Student t tests were used to investigate gender differences in the amount of time invested in work prenatally, perceived degree of sharing household tasks with the partner, satisfaction with the partner’s contribution to household work, and projected prenatal to postpartum work changes. Paired t tests were used to examine subjects’ anticipated prenatal to postpartum changes in workload. Congruency in partners’ perceptions about how they currently share household responsibilities was determined by summing their responses to the question, “Please circle the number that best describes how you and your partner currently share household responsibilities.” Responses were given on a 1 to 7 scale where 1=“partner does everything,” 4=“We share equally,” and 7=“I do everything.” Thus, a summed score of 8 indicated perfect congruency.

Results

Of the 722 expectant parents informed of the study, 76 were ineligible to participate (usually because they were not living with a partner), 346 refused to participate (the most common reason for refusal was concern about leaving the large classroom for a breakout session), and 300 (149 men and 151 women) agreed to participate, for a response rate of 46% (300/646). The mean age of the participants was 29.3 years (standard deviation=4.6); 93.3% were white; 88.6% were married; 97.9% were employed; and 62% had a 4-year college or advanced degree. A total of 132 people (66 men and 66 women) participated in the breakout sessions.

The amount of time expectant fathers and mothers devoted to various household tasks and employment prenatally is shown in Table 1. Although men and women contributed similar amounts of time to household work—18.2 and 20.0 hours, respectively—they tended to divide these tasks according to traditional work patterns, with men investing more time in household repairs, lawn care, and snow removal, and women spending more time with cooking, cleaning, laundry, and shopping. Compared with women, men worked longer hours at their jobs, and this resulted in a heavier mean total prenatal workload for men by 8.4 hours per week (P=.000).

In response to the question of how they shared household responsibilities, women reported a belief that they contributed more to household chores than their partners (mean=4.4 and 3.8 for women and men, respectively; P=.000). This finding is consistent with women’s slightly higher estimated contributions to household tasks (P=NS). Partners’ perceptions about how they shared household work were congruent: 90% of couples had summed congruency scores in the 7 to 9 range, which allows for no more than a 1-point deviation from a perfect summed congruency score of 8. On average men were more satisfied than women with their partner’s contribution to household work (mean=6.0 and 5.4 for men and women, respectively; P=.000). The projected prenatal to postpartum changes in workload were considerable for both men and women (Table 2). Women predicted an 85% increase, and men anticipated a 53% expansion of total workload, with a net result of women planning to work 9 hours per week more than men at 6 months postpartum (P <.001). Both men and women predicted significant increases in time spent on household tasks, child care, and total work; the projected changes in effort related to child care and total work were significantly greater for women than men (P=.000), as shown in Table 3. Both men and women planned to reduce their paid work commitments after childbirth, women to a greater degree than men (P=.000).

Discussion

The results indicate that while men shouldered heavier workloads prenatally, women anticipated working longer hours than men at 6 months postpartum by 9 hours per week. This amounts to an 85% (48.7 hours/week) increase in workload for women, compared with a 53% (33.3 hours/week) increase for men. Although both are astounding increases, women clearly anticipated a larger expansion of work than men. Such dramatic changes in work responsibilities realized by new mothers might be at least partially responsible for the mental and physical problems that often plague women after childbirth.^8,12

The projected postpartum difference in workload between men and women was not unexpected, given the findings of Kahn¹ that on average, adult women of all ages in the United States bear heavier total workloads than men. It is noteworthy, however, that this gender difference in workloads was anticipated even by a group of couples who had had an opportunity to systematically study and preplan their postpartum work distribution.

It appears that to some degree these planned gender discrepancies in postpartum work responsibilities might be explained on the basis of traditional sex role assumptions. Women planned to take on more of the child care and household responsibilities after childbirth than men: 79 versus 52 hours per week. To help compensate for this considerable expansion of unpaid work, expectant mothers also planned to trim an average of 11.7 hours per week from their paid jobs compared with expectant fathers’ anticipated drop of 2.2 hours per week. For many women this change would likely result in part-time work. Previous studies have documented that both men and women tend to work part-time more in the childbearing years than at any other time in their adult lives, and women’s use of part-time work hours during this period of life tends to be much greater than men’s, often 2 to 3 times more.¹³ These data reinforce the need for couples to consider many complex issues in their postpartum workload planning, such as whether their dissimilar reductions in paid work will have a differential impact on their career satisfaction and opportunities and whether their joint plans for curtailing employment hours could ultimately benefit the family unit by improving child and family development.

Although expectant fathers and mothers in this study tended to follow traditional patterns in their qualitative division of various household responsibilities, they devoted similar amounts of total time to household tasks (18.2 and 20.0 hours/week, respectively). This finding contrasts with that of previous studies showing a much greater share of household work being performed by women,^1,14,15 often twice as much or more.^1,14,16 The results could be related to several factors. First, the observed prenatal work patterns may be somewhat atypical for these couples: Several women indicated that they had cut back on their housework or employment hours because of pregnancy-associated fatigue or other health problems. Second, this was a very homogenous population of employed young couples without children, in contrast to the more diverse samples (which included adults with children and more unemployed wives) used in many previous studies. Alternatively, these findings might represent a societal trend toward men and women sharing housework more equitably.

Importantly for many of these parents, the changes in work that they anticipated after giving birth likely represent the largest and most abrupt increase in work responsibilities that they will face in their adult lives. Unfortunately, it is a change for which many parents are ill-prepared. This lack of preparation is likely due, at least in part, to the paucity of information available on new parents’ actual workloads (no specific information was found in the medical, sociological, and psychological searches), society’s tendency to focus on the health needs of newborns and children more than those of their parents, and the absence of a consistent method for educating adolescents and young adults about the responsibilities of supporting and nurturing a family.

Each of these needs will be addressed. First, additional research is needed on changes in work responsibilities for new parents from more diverse populations, and we need a greater understanding of how these work responsibilities affect health and marital well-being (the goal of the ongoing randomized controlled trial). Second, we need a broader view of postpartum care, such that the physical, mental, and social needs of both the parents and newborn are considered in an ongoing manner. This is a perspective that family physicians are uniquely positioned to adopt and foster within the context of prenatal and postpartum care for the family unit. Moreover, family physicians could also be part of the solution to the third need, that of teaching would-be parents about postpartum work and family responsibilities. These efforts may pay important dividends in strengthening the fiber of the family and improving the well-being of its individual members.

Limitations

The limitations of this study include the modest response rate, the potential for selection bias, and the relatively homogeneous sample. In addition, parents’ estimations of work time may not be completely accurate, and these simple estimations do not account for such factors as the intensity of work at any given time (as when one juggles numerous responsibilities concurrently) or the issue of who holds the ultimate responsibility for a given task. Though future workload projections may be even more inaccurate than current estimations, the results shown here are more than individuals’ guesses about their future work; they represent couples’ intentional plans for sharing postpartum work responsibilities.

Conclusions

These expectant first-time parents anticipated considerable expansions in their work activities after childbirth, with women planning a greater share of the total postpartum workload. This information is important for new parents and for the health care providers who attend them as they resume their household, family, and paid work responsibilities after childbirth.

Acknowledgments

This study was funded by the University of Minnesota graduate school.

The author would like to thank Anne Marie Weber-Main for her editing assistance and Bruce Center for his help with data analysis.

Preterm delivery is one of the most important—and most costly—problems in obstetric medicine. Despite recent advances, nearly 10% of all infants in this country are born preterm.¹ Advances in the care of premature newborns, such as the administration of antenatal corticosteroids, the use of surfactant, and other developments in respiratory technology have improved outcomes, yet a greater emphasis on identifying and managing the causes of premature delivery is needed.

Recent research has indicated that maternal infection probably plays a much greater role in the occurrence of preterm labor than was previously understood. Bacterial byproducts have been shown to stimulate endogenous phospholipase A2, which induces the formation of prostaglandin, an important stimulant of uterine contractions.² Further, neutrophils and their constituent enzymes, together with bacteria and their proteases, weaken the amniochorion, predisposing a woman to premature rupture of membranes.³ A study⁴ comparing placentas from 21 women who delivered before 36 weeks’ gestation with those from 66 women who delivered at term found the rate of infected placentas to be 62% and 12%, respectively.

Specific genital infections have been linked to preterm labor, including sexually transmitted infections secondary to Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis.⁵ Bacterial vaginosis, which is more common and not necessarily sexually transmitted, is associated with a 1.4- to 6.9-fold increased risk of preterm delivery.^6-9 The relatively high prevalence of bacterial vaginosis in the obstetric population (10% to 32%),¹⁰ coupled with evidence that screening and treating the condition reduces the rate of preterm deliveries,^11-13 makes detection important for reducing perinatal morbidity and mortality.

There is scant evidence that can be used to determine the optimal screening regimen for bacterial vaginosis in pregnancy. It is unclear, for example, whether all women should be routinely screened, how often the screening should occur, and which tests should be used. The vaginal pH test may be a valuable screening tool. It is a quick, inexpensive test where values >4.5 indicate the presence of either bacterial vaginosis or trichomoniasis. The sensitivity for detecting bacterial vaginosis with pH testing ranges from 84% to 97%.¹⁴ An elevated vaginal pH level has been shown to be 100% sensitive and 92% specific in screening nonpregnant premenopausal women for aerobic bacterial pathogens (b-hemolytic streptococci, Gardnerella vaginalis, or mixed aerobic organisms).¹⁵ However, little is known about the utility of the vaginal pH level as a screening tool in pregnancy.

The purpose of our study was to determine whether regular prenatal vaginal pH level screening resulted in more frequent diagnoses and treatment of bacterial vaginosis, trichomoniasis, and other genital infections and thus fewer preterm deliveries. In addition, we sought to determine the effectiveness of using recent vaginal symptoms and vaginal pH levels to diagnose bacterial vaginosis and trichomoniasis.

Methods

We enrolled pregnant women of less than 34 weeks’ gestation attending 1 of 3 participating clinics located in the Minneapolis/St. Paul, Minnesota, metropolitan area between July 1, 1996, and December 31, 1997. We calculated that a sample size of 208 women would detect a 50% increase in the diagnosis of bacterial vaginosis with a power of .80 and an a of .05. Women who participated in the study were randomized into experimental and control groups at the initial prenatal visit, using computer-generated random number tables and sealed envelopes containing the patient’s group assignment and study protocol. A study protocol was placed in the patient’s chart to facilitate group-specific clinical procedures and data collection Table 1; therefore, health care providers and subjects were not blinded to the intervention (vaginal pH testing).

During the first prenatal visit, patients from both groups were managed the same: symptoms of preterm labor (regular uterine contractions) and vaginal infection (discharge, burning, itching, and odor) were investigated and recorded as present or absent. The following laboratory tests were performed: vaginal pH, wet mount, dieoxyribonucleic acid (DNA) probe for C trachomatis and N gonorrhoeae, and urinalysis.

At each subsequent prenatal visit, women from both groups were asked about symptoms of preterm labor, vaginal infection, and urinary tract infection. Women in either group who reported symptoms of preterm labor had a wet mount examination, DNA probe, and urinalysis performed; women with vaginal symptoms had a wet mount and DNA probe performed. Experimental and control group subjects differed in that experimental group members had a vaginal pH level tested by their physician at each prenatal visit (controls did not have pH testing after the initial visit), and women with a pH level >4.5 also had a wet mount examination performed. The vaginal pH level was tested using a strip of specially formulated pH paper with an enhanced range in the spectrum of interest (pH = 4.0 to 5.5; paper manufactured by Micro Essential Laboratory, Brooklyn, NY). Participating study physicians were instructed in the technique for determining vaginal pH levels. The patient’s physician recorded the pH value in the medical record.

For the purposes of our study, a wet mount evaluation by a medical technologist was used to diagnose bacterial vaginosis, trichomoniasis, and vulvovaginal candidiasis. Participating medical technologists were formally trained in laboratory procedures and were required to have proficiency testing on wet mount examinations 3 times a year. The medical technologists were blinded to participants’ group assignments. Our selection of the wet mount examination as the confirmatory diagnostic test for vaginal infections was made on the basis of its applicability to each of the 3 types of infection, its utility for private practice (relatively easy to perform and inexpensive), and on previous data reporting its relatively high sensitivity for the diagnosis of G vaginalis, the most prevalent bacteria in bacterial vaginosis. The sensitivity of the wet mount for detecting G vaginalis and T vaginalis is 90% and 100%, respectively, when synthetic oligonucleotide probes are used as a gold standard.¹⁶ Other researchers have also used medical technologists’ readings of wet mounts as a standard for the diagnosis of bacterial vaginosis.¹⁷

Women from both experimental and control groups who were diagnosed with a specific vaginal or cervical infection were given standard antimicrobial treatments specified in the study protocol. Although most women diagnosed with bacterial vaginosis or trichomoniasis received oral antibiotics (metronidazole 500 mg twice daily for 7 days or clindamycin 300 mg twice daily for 7 days), a minority were treated with vaginal antimicrobials.

Hospital charts were also reviewed for gestational age at the time of delivery. Gestational age was determined using clinical parameters with ultrasound confirmation for cases where clinical dates were uncertain. Women who delivered at 20 weeks’ to less than 37 weeks’ gestation were categorized as having had a preterm delivery, consistent with accepted definitions.¹⁸

We used the chi-square test to look for significant differences between the 2 groups in infection, antibiotic treatment, and preterm delivery rates. The sensitivity and specificity of vaginal pH values and symptom reports for detecting bacterial vaginosis and T vaginalis were determined using data from the initial prenatal visits, where both vaginal pH and wet mount examinations were routinely performed.

Results

We invited a total of 243 women to participate in our study. Not all eligible patients who were pregnant at the time of the study were asked to participate because of staff changes and work demands. One hundred one declined to participate because of a reluctance to undergo routine vaginal examinations. Twenty-one additional women initially expressed interest in the study, but subsequently transferred care or had a spontaneous or induced abortion before their first formal prenatal visit. The 121 women randomized into our study (63 women in the experimental group; 58 in the control group) represented an overall response rate of 50% (number of participants divided by number of women invited to participate). Two women were pregnant twice during the course of the study, resulting in 123 total pregnancies. There were 910 prenatal visits during the course of the study, with an average of 7.4 prenatal visits per pregnancy. When our study population was compared with nonparticipating obstetrical patients at the 3 clinic sites, no differences were seen in age and proportion of women insured by public assistance. However, compared with nonparticipants, the study sample included a higher proportion of whites.

The mean age of the participants was 24.8 years (standard deviation = 5.4), and 60.2% of the women were on public assistance. The population included several ethnic groups: 47.2% were African American; 36.6% white; 4.1% Native American; 3.3% Asian; 1.6% Hispanic; and 7.2% unknown or other. There were no differences between experimental and control groups in age, ethnicity, and proportion of women on public assistance.

Women who underwent regular vaginal pH screening in addition to standard prenatal care showed significantly higher rates for the diagnosis of bacterial vaginosis, more frequent diagnosis of trichomoniasis (not statistically significant), higher antibiotic treatment rates for bacterial vaginosis and trichomoniasis (46.9% vs 27.1%, P = .024), and a lower rate of preterm births (not statistically significant; Table 2.

The sensitivity of a high vaginal pH level or vaginal symptoms in identifying women with bacterial vaginosis or trichomoniasis was 84.4% Table 3. Although the specificity of either of these tests for identifying bacterial vaginosis or trichomoniasis was modest (57.1%), it rose to 78.5% when both a high pH value and vaginal symptoms were present. Of the 27 women were given a diagnosis of and treatment for bacterial vaginosis and had follow-up wet mount evaluations,¹⁵ (55.6%) had recurrent or persistent bacterial vaginosis.

Discussion

In our study, regular testing for vaginal pH levels at prenatal examinations resulted in significantly more diagnoses of bacterial vaginosis and more antibiotic prescriptions. Increased recognition and treatment of bacterial vaginosis may have contributed to the reduced number of preterm deliveries seen in the experimental group; however, we did not calculate our sample size using preterm delivery as a primary outcome, and the number of women we recruited fell short of the number required to detect a significant difference in the preterm delivery rate.

Given the randomized design of this study, the 1.8-fold increase in the rate of diagnosis of bacterial vaginosis among experimental subjects compared with controls (48.4% vs 27.1%) was likely a result of the increased screening with vaginal pH testing. It is noteworthy that the prevalence of bacterial vaginosis in the control group (27%) is near the upper end of the 10% to 32% range reported for other previously studied obstetric populations.¹⁰ This high-normal rate of infection may be related to the relatively high proportion of women of lower socioeconomic status, a group known to be at risk for preterm labor.¹⁹ In addition, our procedure of asking both experimental and control subjects about symptoms of vaginal infection as a routine part of each prenatal visit may have increased the rate of detecting infections for both groups. Given the high-risk nature of our population, it is notable that our controls had a preterm birth rate (10.2%) comparable with that of the general population,¹ and the experimental group’s preterm birth rate (4.7%) was less than half that of the controls.

A high vaginal pH value, vaginal symptoms, or both had 84% sensitivity to detect bacterial vaginosis or trichomoniasis. Inquiring about a history of vaginal symptoms and testing for vaginal pH levels are inexpensive procedures that could easily be implemented as part of routine prenatal care. If larger studies confirm its impact on the detection of infection and the preterm delivery rate, vaginal pH testing will merit wide use as a screening tool, with its results confirmed by more specific diagnostic procedures, such as the wet mount or Gram stain.

Nearly half of our sample received antimicrobial prescriptions for vaginal infections. Yet 56% of those treated who also had follow-up wet mount examinations had either persistent or recurrent bacterial vaginosis. This rate is 3 times higher than the 18% recurrence rate previously reported²⁰ and may indicate either noncompliance, resistance to the medication, or a tendency toward recurrence. Women who continue to have evidence of infection may remain at risk for preterm birth. A more effective strategy for eliminating bacterial vaginosis resulting in a lower rate of persistence or recurrence in the experimental group may have improved the preterm labor outcomes for women undergoing regular screening.

Limitations

An important limitation of this study is the relatively small sample size. Although we demonstrated a significant difference in our primary outcome (infection rates), the more compelling clinical outcome is preterm delivery rate. McGregor and colleagues¹¹ demonstrated a 50% reduction in bacterial-vaginosis–linked idiopathic preterm births with a program of screening for and treating bacterial vaginosis.¹¹ To have 80% power to show a reduction in preterm birth from 10% to 5%, we would have needed a sample size of 336 mothers in each group—a number beyond our capacity to fund and recruit.

Our difficulty in recruiting women resulted from our failure to invite all eligible women to participate and from the refusals to participate because we required frequent vaginal examinations. The observation that so many women disliked the idea of regular prenatal vaginal examinations suggests that we should investigate ways of making the vaginal pH test more acceptable, perhaps through self-testing. It is also possible that other populations (eg, women with previous preterm births or women of higher socioeconomic status) would be more open to regular pH testing.

Additional limitations of our study include potential selection bias, which may reduce the generalizability of our findings, and the fact that patients and providers were not blinded to the intervention. It would be helpful to minimize these potential sources of bias in a large-scale blinded randomized trial. Future studies should also differentiate the causes of positive results in follow-up tests and should examine the benefit of treating asymptomatic infections and doing follow-up tests for cure.

Conclusions

Our frequent screening procedures significantly increased the recognition of bacterial vaginosis and the treatment of infected women. Since vaginal symptoms and elevated pH levels appear to be useful in screening for bacterial vaginosis and trichomoniasis, frequent pH testing should be evaluated in larger studies.

Acknowledgments

This study was supported by a grant from the UCare Foundation.

Preterm delivery is one of the most important—and most costly—problems in obstetric medicine. Despite recent advances, nearly 10% of all infants in this country are born preterm.¹ Advances in the care of premature newborns, such as the administration of antenatal corticosteroids, the use of surfactant, and other developments in respiratory technology have improved outcomes, yet a greater emphasis on identifying and managing the causes of premature delivery is needed.

Recent research has indicated that maternal infection probably plays a much greater role in the occurrence of preterm labor than was previously understood. Bacterial byproducts have been shown to stimulate endogenous phospholipase A2, which induces the formation of prostaglandin, an important stimulant of uterine contractions.² Further, neutrophils and their constituent enzymes, together with bacteria and their proteases, weaken the amniochorion, predisposing a woman to premature rupture of membranes.³ A study⁴ comparing placentas from 21 women who delivered before 36 weeks’ gestation with those from 66 women who delivered at term found the rate of infected placentas to be 62% and 12%, respectively.

Specific genital infections have been linked to preterm labor, including sexually transmitted infections secondary to Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis.⁵ Bacterial vaginosis, which is more common and not necessarily sexually transmitted, is associated with a 1.4- to 6.9-fold increased risk of preterm delivery.^6-9 The relatively high prevalence of bacterial vaginosis in the obstetric population (10% to 32%),¹⁰ coupled with evidence that screening and treating the condition reduces the rate of preterm deliveries,^11-13 makes detection important for reducing perinatal morbidity and mortality.

There is scant evidence that can be used to determine the optimal screening regimen for bacterial vaginosis in pregnancy. It is unclear, for example, whether all women should be routinely screened, how often the screening should occur, and which tests should be used. The vaginal pH test may be a valuable screening tool. It is a quick, inexpensive test where values >4.5 indicate the presence of either bacterial vaginosis or trichomoniasis. The sensitivity for detecting bacterial vaginosis with pH testing ranges from 84% to 97%.¹⁴ An elevated vaginal pH level has been shown to be 100% sensitive and 92% specific in screening nonpregnant premenopausal women for aerobic bacterial pathogens (b-hemolytic streptococci, Gardnerella vaginalis, or mixed aerobic organisms).¹⁵ However, little is known about the utility of the vaginal pH level as a screening tool in pregnancy.

The purpose of our study was to determine whether regular prenatal vaginal pH level screening resulted in more frequent diagnoses and treatment of bacterial vaginosis, trichomoniasis, and other genital infections and thus fewer preterm deliveries. In addition, we sought to determine the effectiveness of using recent vaginal symptoms and vaginal pH levels to diagnose bacterial vaginosis and trichomoniasis.

Methods

We enrolled pregnant women of less than 34 weeks’ gestation attending 1 of 3 participating clinics located in the Minneapolis/St. Paul, Minnesota, metropolitan area between July 1, 1996, and December 31, 1997. We calculated that a sample size of 208 women would detect a 50% increase in the diagnosis of bacterial vaginosis with a power of .80 and an a of .05. Women who participated in the study were randomized into experimental and control groups at the initial prenatal visit, using computer-generated random number tables and sealed envelopes containing the patient’s group assignment and study protocol. A study protocol was placed in the patient’s chart to facilitate group-specific clinical procedures and data collection Table 1; therefore, health care providers and subjects were not blinded to the intervention (vaginal pH testing).

During the first prenatal visit, patients from both groups were managed the same: symptoms of preterm labor (regular uterine contractions) and vaginal infection (discharge, burning, itching, and odor) were investigated and recorded as present or absent. The following laboratory tests were performed: vaginal pH, wet mount, dieoxyribonucleic acid (DNA) probe for C trachomatis and N gonorrhoeae, and urinalysis.

At each subsequent prenatal visit, women from both groups were asked about symptoms of preterm labor, vaginal infection, and urinary tract infection. Women in either group who reported symptoms of preterm labor had a wet mount examination, DNA probe, and urinalysis performed; women with vaginal symptoms had a wet mount and DNA probe performed. Experimental and control group subjects differed in that experimental group members had a vaginal pH level tested by their physician at each prenatal visit (controls did not have pH testing after the initial visit), and women with a pH level >4.5 also had a wet mount examination performed. The vaginal pH level was tested using a strip of specially formulated pH paper with an enhanced range in the spectrum of interest (pH = 4.0 to 5.5; paper manufactured by Micro Essential Laboratory, Brooklyn, NY). Participating study physicians were instructed in the technique for determining vaginal pH levels. The patient’s physician recorded the pH value in the medical record.

For the purposes of our study, a wet mount evaluation by a medical technologist was used to diagnose bacterial vaginosis, trichomoniasis, and vulvovaginal candidiasis. Participating medical technologists were formally trained in laboratory procedures and were required to have proficiency testing on wet mount examinations 3 times a year. The medical technologists were blinded to participants’ group assignments. Our selection of the wet mount examination as the confirmatory diagnostic test for vaginal infections was made on the basis of its applicability to each of the 3 types of infection, its utility for private practice (relatively easy to perform and inexpensive), and on previous data reporting its relatively high sensitivity for the diagnosis of G vaginalis, the most prevalent bacteria in bacterial vaginosis. The sensitivity of the wet mount for detecting G vaginalis and T vaginalis is 90% and 100%, respectively, when synthetic oligonucleotide probes are used as a gold standard.¹⁶ Other researchers have also used medical technologists’ readings of wet mounts as a standard for the diagnosis of bacterial vaginosis.¹⁷

Women from both experimental and control groups who were diagnosed with a specific vaginal or cervical infection were given standard antimicrobial treatments specified in the study protocol. Although most women diagnosed with bacterial vaginosis or trichomoniasis received oral antibiotics (metronidazole 500 mg twice daily for 7 days or clindamycin 300 mg twice daily for 7 days), a minority were treated with vaginal antimicrobials.

Hospital charts were also reviewed for gestational age at the time of delivery. Gestational age was determined using clinical parameters with ultrasound confirmation for cases where clinical dates were uncertain. Women who delivered at 20 weeks’ to less than 37 weeks’ gestation were categorized as having had a preterm delivery, consistent with accepted definitions.¹⁸

We used the chi-square test to look for significant differences between the 2 groups in infection, antibiotic treatment, and preterm delivery rates. The sensitivity and specificity of vaginal pH values and symptom reports for detecting bacterial vaginosis and T vaginalis were determined using data from the initial prenatal visits, where both vaginal pH and wet mount examinations were routinely performed.

Results

We invited a total of 243 women to participate in our study. Not all eligible patients who were pregnant at the time of the study were asked to participate because of staff changes and work demands. One hundred one declined to participate because of a reluctance to undergo routine vaginal examinations. Twenty-one additional women initially expressed interest in the study, but subsequently transferred care or had a spontaneous or induced abortion before their first formal prenatal visit. The 121 women randomized into our study (63 women in the experimental group; 58 in the control group) represented an overall response rate of 50% (number of participants divided by number of women invited to participate). Two women were pregnant twice during the course of the study, resulting in 123 total pregnancies. There were 910 prenatal visits during the course of the study, with an average of 7.4 prenatal visits per pregnancy. When our study population was compared with nonparticipating obstetrical patients at the 3 clinic sites, no differences were seen in age and proportion of women insured by public assistance. However, compared with nonparticipants, the study sample included a higher proportion of whites.

The mean age of the participants was 24.8 years (standard deviation = 5.4), and 60.2% of the women were on public assistance. The population included several ethnic groups: 47.2% were African American; 36.6% white; 4.1% Native American; 3.3% Asian; 1.6% Hispanic; and 7.2% unknown or other. There were no differences between experimental and control groups in age, ethnicity, and proportion of women on public assistance.

Women who underwent regular vaginal pH screening in addition to standard prenatal care showed significantly higher rates for the diagnosis of bacterial vaginosis, more frequent diagnosis of trichomoniasis (not statistically significant), higher antibiotic treatment rates for bacterial vaginosis and trichomoniasis (46.9% vs 27.1%, P = .024), and a lower rate of preterm births (not statistically significant; Table 2.

The sensitivity of a high vaginal pH level or vaginal symptoms in identifying women with bacterial vaginosis or trichomoniasis was 84.4% Table 3. Although the specificity of either of these tests for identifying bacterial vaginosis or trichomoniasis was modest (57.1%), it rose to 78.5% when both a high pH value and vaginal symptoms were present. Of the 27 women were given a diagnosis of and treatment for bacterial vaginosis and had follow-up wet mount evaluations,¹⁵ (55.6%) had recurrent or persistent bacterial vaginosis.

Discussion

In our study, regular testing for vaginal pH levels at prenatal examinations resulted in significantly more diagnoses of bacterial vaginosis and more antibiotic prescriptions. Increased recognition and treatment of bacterial vaginosis may have contributed to the reduced number of preterm deliveries seen in the experimental group; however, we did not calculate our sample size using preterm delivery as a primary outcome, and the number of women we recruited fell short of the number required to detect a significant difference in the preterm delivery rate.

Given the randomized design of this study, the 1.8-fold increase in the rate of diagnosis of bacterial vaginosis among experimental subjects compared with controls (48.4% vs 27.1%) was likely a result of the increased screening with vaginal pH testing. It is noteworthy that the prevalence of bacterial vaginosis in the control group (27%) is near the upper end of the 10% to 32% range reported for other previously studied obstetric populations.¹⁰ This high-normal rate of infection may be related to the relatively high proportion of women of lower socioeconomic status, a group known to be at risk for preterm labor.¹⁹ In addition, our procedure of asking both experimental and control subjects about symptoms of vaginal infection as a routine part of each prenatal visit may have increased the rate of detecting infections for both groups. Given the high-risk nature of our population, it is notable that our controls had a preterm birth rate (10.2%) comparable with that of the general population,¹ and the experimental group’s preterm birth rate (4.7%) was less than half that of the controls.

A high vaginal pH value, vaginal symptoms, or both had 84% sensitivity to detect bacterial vaginosis or trichomoniasis. Inquiring about a history of vaginal symptoms and testing for vaginal pH levels are inexpensive procedures that could easily be implemented as part of routine prenatal care. If larger studies confirm its impact on the detection of infection and the preterm delivery rate, vaginal pH testing will merit wide use as a screening tool, with its results confirmed by more specific diagnostic procedures, such as the wet mount or Gram stain.

Nearly half of our sample received antimicrobial prescriptions for vaginal infections. Yet 56% of those treated who also had follow-up wet mount examinations had either persistent or recurrent bacterial vaginosis. This rate is 3 times higher than the 18% recurrence rate previously reported²⁰ and may indicate either noncompliance, resistance to the medication, or a tendency toward recurrence. Women who continue to have evidence of infection may remain at risk for preterm birth. A more effective strategy for eliminating bacterial vaginosis resulting in a lower rate of persistence or recurrence in the experimental group may have improved the preterm labor outcomes for women undergoing regular screening.

Limitations

An important limitation of this study is the relatively small sample size. Although we demonstrated a significant difference in our primary outcome (infection rates), the more compelling clinical outcome is preterm delivery rate. McGregor and colleagues¹¹ demonstrated a 50% reduction in bacterial-vaginosis–linked idiopathic preterm births with a program of screening for and treating bacterial vaginosis.¹¹ To have 80% power to show a reduction in preterm birth from 10% to 5%, we would have needed a sample size of 336 mothers in each group—a number beyond our capacity to fund and recruit.

Our difficulty in recruiting women resulted from our failure to invite all eligible women to participate and from the refusals to participate because we required frequent vaginal examinations. The observation that so many women disliked the idea of regular prenatal vaginal examinations suggests that we should investigate ways of making the vaginal pH test more acceptable, perhaps through self-testing. It is also possible that other populations (eg, women with previous preterm births or women of higher socioeconomic status) would be more open to regular pH testing.

Additional limitations of our study include potential selection bias, which may reduce the generalizability of our findings, and the fact that patients and providers were not blinded to the intervention. It would be helpful to minimize these potential sources of bias in a large-scale blinded randomized trial. Future studies should also differentiate the causes of positive results in follow-up tests and should examine the benefit of treating asymptomatic infections and doing follow-up tests for cure.

Conclusions

Our frequent screening procedures significantly increased the recognition of bacterial vaginosis and the treatment of infected women. Since vaginal symptoms and elevated pH levels appear to be useful in screening for bacterial vaginosis and trichomoniasis, frequent pH testing should be evaluated in larger studies.

Acknowledgments

This study was supported by a grant from the UCare Foundation.

Preterm delivery is one of the most important—and most costly—problems in obstetric medicine. Despite recent advances, nearly 10% of all infants in this country are born preterm.¹ Advances in the care of premature newborns, such as the administration of antenatal corticosteroids, the use of surfactant, and other developments in respiratory technology have improved outcomes, yet a greater emphasis on identifying and managing the causes of premature delivery is needed.

Recent research has indicated that maternal infection probably plays a much greater role in the occurrence of preterm labor than was previously understood. Bacterial byproducts have been shown to stimulate endogenous phospholipase A2, which induces the formation of prostaglandin, an important stimulant of uterine contractions.² Further, neutrophils and their constituent enzymes, together with bacteria and their proteases, weaken the amniochorion, predisposing a woman to premature rupture of membranes.³ A study⁴ comparing placentas from 21 women who delivered before 36 weeks’ gestation with those from 66 women who delivered at term found the rate of infected placentas to be 62% and 12%, respectively.

Specific genital infections have been linked to preterm labor, including sexually transmitted infections secondary to Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis.⁵ Bacterial vaginosis, which is more common and not necessarily sexually transmitted, is associated with a 1.4- to 6.9-fold increased risk of preterm delivery.^6-9 The relatively high prevalence of bacterial vaginosis in the obstetric population (10% to 32%),¹⁰ coupled with evidence that screening and treating the condition reduces the rate of preterm deliveries,^11-13 makes detection important for reducing perinatal morbidity and mortality.

There is scant evidence that can be used to determine the optimal screening regimen for bacterial vaginosis in pregnancy. It is unclear, for example, whether all women should be routinely screened, how often the screening should occur, and which tests should be used. The vaginal pH test may be a valuable screening tool. It is a quick, inexpensive test where values >4.5 indicate the presence of either bacterial vaginosis or trichomoniasis. The sensitivity for detecting bacterial vaginosis with pH testing ranges from 84% to 97%.¹⁴ An elevated vaginal pH level has been shown to be 100% sensitive and 92% specific in screening nonpregnant premenopausal women for aerobic bacterial pathogens (b-hemolytic streptococci, Gardnerella vaginalis, or mixed aerobic organisms).¹⁵ However, little is known about the utility of the vaginal pH level as a screening tool in pregnancy.

The purpose of our study was to determine whether regular prenatal vaginal pH level screening resulted in more frequent diagnoses and treatment of bacterial vaginosis, trichomoniasis, and other genital infections and thus fewer preterm deliveries. In addition, we sought to determine the effectiveness of using recent vaginal symptoms and vaginal pH levels to diagnose bacterial vaginosis and trichomoniasis.

Methods

We enrolled pregnant women of less than 34 weeks’ gestation attending 1 of 3 participating clinics located in the Minneapolis/St. Paul, Minnesota, metropolitan area between July 1, 1996, and December 31, 1997. We calculated that a sample size of 208 women would detect a 50% increase in the diagnosis of bacterial vaginosis with a power of .80 and an a of .05. Women who participated in the study were randomized into experimental and control groups at the initial prenatal visit, using computer-generated random number tables and sealed envelopes containing the patient’s group assignment and study protocol. A study protocol was placed in the patient’s chart to facilitate group-specific clinical procedures and data collection Table 1; therefore, health care providers and subjects were not blinded to the intervention (vaginal pH testing).

During the first prenatal visit, patients from both groups were managed the same: symptoms of preterm labor (regular uterine contractions) and vaginal infection (discharge, burning, itching, and odor) were investigated and recorded as present or absent. The following laboratory tests were performed: vaginal pH, wet mount, dieoxyribonucleic acid (DNA) probe for C trachomatis and N gonorrhoeae, and urinalysis.

At each subsequent prenatal visit, women from both groups were asked about symptoms of preterm labor, vaginal infection, and urinary tract infection. Women in either group who reported symptoms of preterm labor had a wet mount examination, DNA probe, and urinalysis performed; women with vaginal symptoms had a wet mount and DNA probe performed. Experimental and control group subjects differed in that experimental group members had a vaginal pH level tested by their physician at each prenatal visit (controls did not have pH testing after the initial visit), and women with a pH level >4.5 also had a wet mount examination performed. The vaginal pH level was tested using a strip of specially formulated pH paper with an enhanced range in the spectrum of interest (pH = 4.0 to 5.5; paper manufactured by Micro Essential Laboratory, Brooklyn, NY). Participating study physicians were instructed in the technique for determining vaginal pH levels. The patient’s physician recorded the pH value in the medical record.

For the purposes of our study, a wet mount evaluation by a medical technologist was used to diagnose bacterial vaginosis, trichomoniasis, and vulvovaginal candidiasis. Participating medical technologists were formally trained in laboratory procedures and were required to have proficiency testing on wet mount examinations 3 times a year. The medical technologists were blinded to participants’ group assignments. Our selection of the wet mount examination as the confirmatory diagnostic test for vaginal infections was made on the basis of its applicability to each of the 3 types of infection, its utility for private practice (relatively easy to perform and inexpensive), and on previous data reporting its relatively high sensitivity for the diagnosis of G vaginalis, the most prevalent bacteria in bacterial vaginosis. The sensitivity of the wet mount for detecting G vaginalis and T vaginalis is 90% and 100%, respectively, when synthetic oligonucleotide probes are used as a gold standard.¹⁶ Other researchers have also used medical technologists’ readings of wet mounts as a standard for the diagnosis of bacterial vaginosis.¹⁷

Women from both experimental and control groups who were diagnosed with a specific vaginal or cervical infection were given standard antimicrobial treatments specified in the study protocol. Although most women diagnosed with bacterial vaginosis or trichomoniasis received oral antibiotics (metronidazole 500 mg twice daily for 7 days or clindamycin 300 mg twice daily for 7 days), a minority were treated with vaginal antimicrobials.

Hospital charts were also reviewed for gestational age at the time of delivery. Gestational age was determined using clinical parameters with ultrasound confirmation for cases where clinical dates were uncertain. Women who delivered at 20 weeks’ to less than 37 weeks’ gestation were categorized as having had a preterm delivery, consistent with accepted definitions.¹⁸

We used the chi-square test to look for significant differences between the 2 groups in infection, antibiotic treatment, and preterm delivery rates. The sensitivity and specificity of vaginal pH values and symptom reports for detecting bacterial vaginosis and T vaginalis were determined using data from the initial prenatal visits, where both vaginal pH and wet mount examinations were routinely performed.

Results

We invited a total of 243 women to participate in our study. Not all eligible patients who were pregnant at the time of the study were asked to participate because of staff changes and work demands. One hundred one declined to participate because of a reluctance to undergo routine vaginal examinations. Twenty-one additional women initially expressed interest in the study, but subsequently transferred care or had a spontaneous or induced abortion before their first formal prenatal visit. The 121 women randomized into our study (63 women in the experimental group; 58 in the control group) represented an overall response rate of 50% (number of participants divided by number of women invited to participate). Two women were pregnant twice during the course of the study, resulting in 123 total pregnancies. There were 910 prenatal visits during the course of the study, with an average of 7.4 prenatal visits per pregnancy. When our study population was compared with nonparticipating obstetrical patients at the 3 clinic sites, no differences were seen in age and proportion of women insured by public assistance. However, compared with nonparticipants, the study sample included a higher proportion of whites.

The mean age of the participants was 24.8 years (standard deviation = 5.4), and 60.2% of the women were on public assistance. The population included several ethnic groups: 47.2% were African American; 36.6% white; 4.1% Native American; 3.3% Asian; 1.6% Hispanic; and 7.2% unknown or other. There were no differences between experimental and control groups in age, ethnicity, and proportion of women on public assistance.

Women who underwent regular vaginal pH screening in addition to standard prenatal care showed significantly higher rates for the diagnosis of bacterial vaginosis, more frequent diagnosis of trichomoniasis (not statistically significant), higher antibiotic treatment rates for bacterial vaginosis and trichomoniasis (46.9% vs 27.1%, P = .024), and a lower rate of preterm births (not statistically significant; Table 2.

The sensitivity of a high vaginal pH level or vaginal symptoms in identifying women with bacterial vaginosis or trichomoniasis was 84.4% Table 3. Although the specificity of either of these tests for identifying bacterial vaginosis or trichomoniasis was modest (57.1%), it rose to 78.5% when both a high pH value and vaginal symptoms were present. Of the 27 women were given a diagnosis of and treatment for bacterial vaginosis and had follow-up wet mount evaluations,¹⁵ (55.6%) had recurrent or persistent bacterial vaginosis.

Discussion

In our study, regular testing for vaginal pH levels at prenatal examinations resulted in significantly more diagnoses of bacterial vaginosis and more antibiotic prescriptions. Increased recognition and treatment of bacterial vaginosis may have contributed to the reduced number of preterm deliveries seen in the experimental group; however, we did not calculate our sample size using preterm delivery as a primary outcome, and the number of women we recruited fell short of the number required to detect a significant difference in the preterm delivery rate.

Given the randomized design of this study, the 1.8-fold increase in the rate of diagnosis of bacterial vaginosis among experimental subjects compared with controls (48.4% vs 27.1%) was likely a result of the increased screening with vaginal pH testing. It is noteworthy that the prevalence of bacterial vaginosis in the control group (27%) is near the upper end of the 10% to 32% range reported for other previously studied obstetric populations.¹⁰ This high-normal rate of infection may be related to the relatively high proportion of women of lower socioeconomic status, a group known to be at risk for preterm labor.¹⁹ In addition, our procedure of asking both experimental and control subjects about symptoms of vaginal infection as a routine part of each prenatal visit may have increased the rate of detecting infections for both groups. Given the high-risk nature of our population, it is notable that our controls had a preterm birth rate (10.2%) comparable with that of the general population,¹ and the experimental group’s preterm birth rate (4.7%) was less than half that of the controls.

A high vaginal pH value, vaginal symptoms, or both had 84% sensitivity to detect bacterial vaginosis or trichomoniasis. Inquiring about a history of vaginal symptoms and testing for vaginal pH levels are inexpensive procedures that could easily be implemented as part of routine prenatal care. If larger studies confirm its impact on the detection of infection and the preterm delivery rate, vaginal pH testing will merit wide use as a screening tool, with its results confirmed by more specific diagnostic procedures, such as the wet mount or Gram stain.

Nearly half of our sample received antimicrobial prescriptions for vaginal infections. Yet 56% of those treated who also had follow-up wet mount examinations had either persistent or recurrent bacterial vaginosis. This rate is 3 times higher than the 18% recurrence rate previously reported²⁰ and may indicate either noncompliance, resistance to the medication, or a tendency toward recurrence. Women who continue to have evidence of infection may remain at risk for preterm birth. A more effective strategy for eliminating bacterial vaginosis resulting in a lower rate of persistence or recurrence in the experimental group may have improved the preterm labor outcomes for women undergoing regular screening.

Limitations

An important limitation of this study is the relatively small sample size. Although we demonstrated a significant difference in our primary outcome (infection rates), the more compelling clinical outcome is preterm delivery rate. McGregor and colleagues¹¹ demonstrated a 50% reduction in bacterial-vaginosis–linked idiopathic preterm births with a program of screening for and treating bacterial vaginosis.¹¹ To have 80% power to show a reduction in preterm birth from 10% to 5%, we would have needed a sample size of 336 mothers in each group—a number beyond our capacity to fund and recruit.

Our difficulty in recruiting women resulted from our failure to invite all eligible women to participate and from the refusals to participate because we required frequent vaginal examinations. The observation that so many women disliked the idea of regular prenatal vaginal examinations suggests that we should investigate ways of making the vaginal pH test more acceptable, perhaps through self-testing. It is also possible that other populations (eg, women with previous preterm births or women of higher socioeconomic status) would be more open to regular pH testing.

Additional limitations of our study include potential selection bias, which may reduce the generalizability of our findings, and the fact that patients and providers were not blinded to the intervention. It would be helpful to minimize these potential sources of bias in a large-scale blinded randomized trial. Future studies should also differentiate the causes of positive results in follow-up tests and should examine the benefit of treating asymptomatic infections and doing follow-up tests for cure.

Conclusions

Our frequent screening procedures significantly increased the recognition of bacterial vaginosis and the treatment of infected women. Since vaginal symptoms and elevated pH levels appear to be useful in screening for bacterial vaginosis and trichomoniasis, frequent pH testing should be evaluated in larger studies.

Acknowledgments

This study was supported by a grant from the UCare Foundation.