ACOG 2014

CHICAGO – Uterine perforation rates are low for both the levonorgestrel intrauterine device and copper devices, and do not differ significantly between the two, according to the multinational EURAS-IUD study of more than 61,400 women.

Between 2006 and 2013, the rate of perforation among new users of levonorgestrel IUDs was 1.4/1,000 insertions and the rate for copper IUDs was 1.1/1,000 insertions, according to Dr. Klaas Heinemannn of ZEG-Berlin, who presented his prize-winning abstract at the annual meeting of the American Congress of Obstetricians and Gynecologists.

However, a striking difference was seen in the perforation rate among first-ever vs. repeat IUD users: 2.5/1,000 levonorgestrel IUDs and 1.4/1,000 for copper IUDs among first-time users, compared with 0.5/1,000 for both types among repeat users.

© EduardoLuzzatti/iStockphoto.com

Of the 81 perforations, 64 were associated with known potential risk factors. For example, 35 women who experienced perforation were breastfeeding at the time of insertion, and 25 of those were breastfeeding at least six times daily. Seven women were treated with prostaglandin prior to insertion.

Breastfeeding was associated with a sixfold increase in risk of perforation with both the levonorgestrel and copper IUDs, Dr. Heinemann said.

None of the perforations in this study led to serious illness or injury to an internal organ, he noted.

Levonorgestrel IUD use was associated with a 10-fold decrease in the contraceptive failure rate, compared with copper IUDs. The rate of contraceptive failure did not differ significantly between the different types of copper IUDs used in the study. Similarly, the ectopic pregnancy rate was lower in the levonorgestrel IUD group, he noted.

The prospective, noninterventional EUSAR-IUD cohort study included 61,448 women from Germany, Austria, United Kingdom, Finland, Poland, and Sweden. The women completed follow-up questionnaires at 12 months after enrollment, and all patient-reported outcomes of interest were validated by the treating physician.

Most (about 70%) of the women used levonorgestrel IUDs, and about 30% used copper IUDs. Half were first-time users.

Only 2% of participants were lost to follow-up, with no significant difference between the two groups.

Differences between the groups remained significant after adjustment for a number of variables, including age, body mass index, time since last delivery, and breastfeeding.

The most striking difference in use was age. Women in their 20s and 30s used copper IUDs at more than twice the rate of levonorgestrel IUDs, while those aged 40 years and older used levonorgestrel IUDs at twice the rate of copper IUDs.

Although this study is limited by its observational nature, the results suggest that there is no clinically relevant increase in the risk of uterine perforation with either type of IUD, Dr. Heinemann said.

"However, we found a striking difference in the contraceptive failure rate," he said.

Based on the findings, the Safety Monitoring and Advisory Council that oversaw the study concluded that "the health benefits of IUDs outweigh the rare risk of perforation, including for women postpartum and those breastfeeding. No new restrictions in IUD use are warranted based on this study."

This study was supported by an unconditional grant from Bayer Healthcare, which markets Mirena (levonorgestrel-releasing intrauterine system). Dr. Heinemann reported having no disclosures.

CHICAGO – Uterine perforation rates are low for both the levonorgestrel intrauterine device and copper devices, and do not differ significantly between the two, according to the multinational EURAS-IUD study of more than 61,400 women.

Between 2006 and 2013, the rate of perforation among new users of levonorgestrel IUDs was 1.4/1,000 insertions and the rate for copper IUDs was 1.1/1,000 insertions, according to Dr. Klaas Heinemannn of ZEG-Berlin, who presented his prize-winning abstract at the annual meeting of the American Congress of Obstetricians and Gynecologists.

However, a striking difference was seen in the perforation rate among first-ever vs. repeat IUD users: 2.5/1,000 levonorgestrel IUDs and 1.4/1,000 for copper IUDs among first-time users, compared with 0.5/1,000 for both types among repeat users.

© EduardoLuzzatti/iStockphoto.com

Of the 81 perforations, 64 were associated with known potential risk factors. For example, 35 women who experienced perforation were breastfeeding at the time of insertion, and 25 of those were breastfeeding at least six times daily. Seven women were treated with prostaglandin prior to insertion.

Breastfeeding was associated with a sixfold increase in risk of perforation with both the levonorgestrel and copper IUDs, Dr. Heinemann said.

None of the perforations in this study led to serious illness or injury to an internal organ, he noted.

Levonorgestrel IUD use was associated with a 10-fold decrease in the contraceptive failure rate, compared with copper IUDs. The rate of contraceptive failure did not differ significantly between the different types of copper IUDs used in the study. Similarly, the ectopic pregnancy rate was lower in the levonorgestrel IUD group, he noted.

The prospective, noninterventional EUSAR-IUD cohort study included 61,448 women from Germany, Austria, United Kingdom, Finland, Poland, and Sweden. The women completed follow-up questionnaires at 12 months after enrollment, and all patient-reported outcomes of interest were validated by the treating physician.

Most (about 70%) of the women used levonorgestrel IUDs, and about 30% used copper IUDs. Half were first-time users.

Only 2% of participants were lost to follow-up, with no significant difference between the two groups.

Differences between the groups remained significant after adjustment for a number of variables, including age, body mass index, time since last delivery, and breastfeeding.

The most striking difference in use was age. Women in their 20s and 30s used copper IUDs at more than twice the rate of levonorgestrel IUDs, while those aged 40 years and older used levonorgestrel IUDs at twice the rate of copper IUDs.

Although this study is limited by its observational nature, the results suggest that there is no clinically relevant increase in the risk of uterine perforation with either type of IUD, Dr. Heinemann said.

"However, we found a striking difference in the contraceptive failure rate," he said.

Based on the findings, the Safety Monitoring and Advisory Council that oversaw the study concluded that "the health benefits of IUDs outweigh the rare risk of perforation, including for women postpartum and those breastfeeding. No new restrictions in IUD use are warranted based on this study."

This study was supported by an unconditional grant from Bayer Healthcare, which markets Mirena (levonorgestrel-releasing intrauterine system). Dr. Heinemann reported having no disclosures.

CHICAGO – Uterine perforation rates are low for both the levonorgestrel intrauterine device and copper devices, and do not differ significantly between the two, according to the multinational EURAS-IUD study of more than 61,400 women.

Between 2006 and 2013, the rate of perforation among new users of levonorgestrel IUDs was 1.4/1,000 insertions and the rate for copper IUDs was 1.1/1,000 insertions, according to Dr. Klaas Heinemannn of ZEG-Berlin, who presented his prize-winning abstract at the annual meeting of the American Congress of Obstetricians and Gynecologists.

However, a striking difference was seen in the perforation rate among first-ever vs. repeat IUD users: 2.5/1,000 levonorgestrel IUDs and 1.4/1,000 for copper IUDs among first-time users, compared with 0.5/1,000 for both types among repeat users.

© EduardoLuzzatti/iStockphoto.com

Of the 81 perforations, 64 were associated with known potential risk factors. For example, 35 women who experienced perforation were breastfeeding at the time of insertion, and 25 of those were breastfeeding at least six times daily. Seven women were treated with prostaglandin prior to insertion.

Breastfeeding was associated with a sixfold increase in risk of perforation with both the levonorgestrel and copper IUDs, Dr. Heinemann said.

None of the perforations in this study led to serious illness or injury to an internal organ, he noted.

Levonorgestrel IUD use was associated with a 10-fold decrease in the contraceptive failure rate, compared with copper IUDs. The rate of contraceptive failure did not differ significantly between the different types of copper IUDs used in the study. Similarly, the ectopic pregnancy rate was lower in the levonorgestrel IUD group, he noted.

The prospective, noninterventional EUSAR-IUD cohort study included 61,448 women from Germany, Austria, United Kingdom, Finland, Poland, and Sweden. The women completed follow-up questionnaires at 12 months after enrollment, and all patient-reported outcomes of interest were validated by the treating physician.

Most (about 70%) of the women used levonorgestrel IUDs, and about 30% used copper IUDs. Half were first-time users.

Only 2% of participants were lost to follow-up, with no significant difference between the two groups.

Differences between the groups remained significant after adjustment for a number of variables, including age, body mass index, time since last delivery, and breastfeeding.

The most striking difference in use was age. Women in their 20s and 30s used copper IUDs at more than twice the rate of levonorgestrel IUDs, while those aged 40 years and older used levonorgestrel IUDs at twice the rate of copper IUDs.

Although this study is limited by its observational nature, the results suggest that there is no clinically relevant increase in the risk of uterine perforation with either type of IUD, Dr. Heinemann said.

"However, we found a striking difference in the contraceptive failure rate," he said.

Based on the findings, the Safety Monitoring and Advisory Council that oversaw the study concluded that "the health benefits of IUDs outweigh the rare risk of perforation, including for women postpartum and those breastfeeding. No new restrictions in IUD use are warranted based on this study."

This study was supported by an unconditional grant from Bayer Healthcare, which markets Mirena (levonorgestrel-releasing intrauterine system). Dr. Heinemann reported having no disclosures.

Women who experience stillbirth or infant death have extraordinarily high rates of depression and anxiety, which are inadequately addressed, according to findings from the Michigan Mother’s Study.

The effects were particularly pronounced among African American women, according to Dr. Katherine J. Gold who will present the findings of her award-winning abstract on Wednesday at the annual meeting of the American Congress of Obstetricians and Gynecologists.

At 9 months after delivery, the rates of positive screens for a number of mental health issues were dramatically and statistically significantly higher in 377 bereaved women who experienced stillbirth or infant death in the first month, compared with 232 control mothers with live birth who participated in the 2-year longitudinal population-based cohort study. The rates were 23% vs. 8% for depression, 41% vs. 12% for posttraumatic stress disorder, 19% vs. 7% for general anxiety disorder, 19% vs. 6% for social phobia, and 12% vs. 6% for panic disorder for the groups, respectively, said Dr. Gold of the University of Michigan, Ann Arbor.

"These high rates of symptoms were significant even when controlling for demographic factors, prior mental health problems, social support, and interpersonal violence," Dr. Gold said in an interview.

Also, the rates of these mental health issues were similar among mothers who experienced stillbirth and those who experienced infant death, suggesting that both losses can be powerful and traumatic experiences.

Although bereaved African American women had similar levels of distress as other bereaved women, they were significantly less likely to have received treatment, Dr. Gold noted.

This study is the first population-based study to look at mental health outcomes among women who experience perinatal death.

"The findings suggest that bereaved mothers have dramatically higher levels of persistent distress, which may be underrecognized by health care providers. It is important for physicians and midwives to assess for mental health symptoms after a loss," she said adding that because it has been shown that depression during a subsequent pregnancy poses substantial risk to fetal and infant outcomes, identifying and treating depression in women before and during subsequent pregnancy is critical for improving outcomes.

Dr. Gold reported having no disclosures.

Women who experience stillbirth or infant death have extraordinarily high rates of depression and anxiety, which are inadequately addressed, according to findings from the Michigan Mother’s Study.

The effects were particularly pronounced among African American women, according to Dr. Katherine J. Gold who will present the findings of her award-winning abstract on Wednesday at the annual meeting of the American Congress of Obstetricians and Gynecologists.

At 9 months after delivery, the rates of positive screens for a number of mental health issues were dramatically and statistically significantly higher in 377 bereaved women who experienced stillbirth or infant death in the first month, compared with 232 control mothers with live birth who participated in the 2-year longitudinal population-based cohort study. The rates were 23% vs. 8% for depression, 41% vs. 12% for posttraumatic stress disorder, 19% vs. 7% for general anxiety disorder, 19% vs. 6% for social phobia, and 12% vs. 6% for panic disorder for the groups, respectively, said Dr. Gold of the University of Michigan, Ann Arbor.

"These high rates of symptoms were significant even when controlling for demographic factors, prior mental health problems, social support, and interpersonal violence," Dr. Gold said in an interview.

Also, the rates of these mental health issues were similar among mothers who experienced stillbirth and those who experienced infant death, suggesting that both losses can be powerful and traumatic experiences.

Although bereaved African American women had similar levels of distress as other bereaved women, they were significantly less likely to have received treatment, Dr. Gold noted.

This study is the first population-based study to look at mental health outcomes among women who experience perinatal death.

"The findings suggest that bereaved mothers have dramatically higher levels of persistent distress, which may be underrecognized by health care providers. It is important for physicians and midwives to assess for mental health symptoms after a loss," she said adding that because it has been shown that depression during a subsequent pregnancy poses substantial risk to fetal and infant outcomes, identifying and treating depression in women before and during subsequent pregnancy is critical for improving outcomes.

Dr. Gold reported having no disclosures.

Women who experience stillbirth or infant death have extraordinarily high rates of depression and anxiety, which are inadequately addressed, according to findings from the Michigan Mother’s Study.

The effects were particularly pronounced among African American women, according to Dr. Katherine J. Gold who will present the findings of her award-winning abstract on Wednesday at the annual meeting of the American Congress of Obstetricians and Gynecologists.

At 9 months after delivery, the rates of positive screens for a number of mental health issues were dramatically and statistically significantly higher in 377 bereaved women who experienced stillbirth or infant death in the first month, compared with 232 control mothers with live birth who participated in the 2-year longitudinal population-based cohort study. The rates were 23% vs. 8% for depression, 41% vs. 12% for posttraumatic stress disorder, 19% vs. 7% for general anxiety disorder, 19% vs. 6% for social phobia, and 12% vs. 6% for panic disorder for the groups, respectively, said Dr. Gold of the University of Michigan, Ann Arbor.

"These high rates of symptoms were significant even when controlling for demographic factors, prior mental health problems, social support, and interpersonal violence," Dr. Gold said in an interview.

Also, the rates of these mental health issues were similar among mothers who experienced stillbirth and those who experienced infant death, suggesting that both losses can be powerful and traumatic experiences.

Although bereaved African American women had similar levels of distress as other bereaved women, they were significantly less likely to have received treatment, Dr. Gold noted.

This study is the first population-based study to look at mental health outcomes among women who experience perinatal death.

"The findings suggest that bereaved mothers have dramatically higher levels of persistent distress, which may be underrecognized by health care providers. It is important for physicians and midwives to assess for mental health symptoms after a loss," she said adding that because it has been shown that depression during a subsequent pregnancy poses substantial risk to fetal and infant outcomes, identifying and treating depression in women before and during subsequent pregnancy is critical for improving outcomes.

Dr. Gold reported having no disclosures.

Applying topical liquid lidocaine to the vulvar vestibule prior to penetration allows for comfortable intercourse in breast cancer survivors with severe menopausal dyspareunia, according to findings from a randomized, controlled study involving 46 women.

During a double-blind phase of the study, patients randomized to apply 4% aqueous lidocaine had less intercourse pain than those who applied saline (median pain scores of 1.0 and 5.3 out of 10, respectively), according to Dr. Martha F. Goetsch of Oregon Health and Science University, Portland, who will report the finding at the annual meeting of the American Congress of Obstetricians and Gynecologists.

During an open-label phase of the study in which all patients were allowed to apply lidocaine, 37 of 41 (90%) reported comfortable penetration, and sexual distress scores decreased from a median of 30.5 to a median of 14. Additionally, 17 of 20 women (85%) who were abstaining from intercourse because of the discomfort had resumed penetrative intimacy, said Dr. Goetsch, whose abstract was awarded first prize among oral presentations by ACOG.

Patients included in the study were estrogen-deficient breast cancer survivors with severe penetrative dyspareunia not associated with pelvic muscle or organ pain. All had severe vulvovaginal atrophy. During the 1-month blinded phase of the study, the women applied either the lidocaine or the saline to the vulvar vestibule for 3 minutes prior to penetration. Effects of twice-weekly tampon insertion or intercourse were documented in a diary. No partners complained of numbness resulting from the lidocaine.

The findings are notable, because breast cancer survivors number in the millions in the United States alone.

"They often suffer from severe dyspareunia and are urged to refrain from using estrogen, which is the therapy most effective for dyspareunia in menopause," Dr. Goetsch said in an interview.

Furthermore, prior research has focused primarily on vaginal atrophy as the cause of dyspareunia in postmenopausal women.

"This study showed that pain could be prevented even though atrophy was unchanged," she said, noting that this suggests that perhaps atrophy is the wrong therapeutic focus.

"Success came with therapy to the vestibule, not the vagina," she said.

Dr. Goetsch reported having no disclosures.

Applying topical liquid lidocaine to the vulvar vestibule prior to penetration allows for comfortable intercourse in breast cancer survivors with severe menopausal dyspareunia, according to findings from a randomized, controlled study involving 46 women.

During a double-blind phase of the study, patients randomized to apply 4% aqueous lidocaine had less intercourse pain than those who applied saline (median pain scores of 1.0 and 5.3 out of 10, respectively), according to Dr. Martha F. Goetsch of Oregon Health and Science University, Portland, who will report the finding at the annual meeting of the American Congress of Obstetricians and Gynecologists.

During an open-label phase of the study in which all patients were allowed to apply lidocaine, 37 of 41 (90%) reported comfortable penetration, and sexual distress scores decreased from a median of 30.5 to a median of 14. Additionally, 17 of 20 women (85%) who were abstaining from intercourse because of the discomfort had resumed penetrative intimacy, said Dr. Goetsch, whose abstract was awarded first prize among oral presentations by ACOG.

Patients included in the study were estrogen-deficient breast cancer survivors with severe penetrative dyspareunia not associated with pelvic muscle or organ pain. All had severe vulvovaginal atrophy. During the 1-month blinded phase of the study, the women applied either the lidocaine or the saline to the vulvar vestibule for 3 minutes prior to penetration. Effects of twice-weekly tampon insertion or intercourse were documented in a diary. No partners complained of numbness resulting from the lidocaine.

The findings are notable, because breast cancer survivors number in the millions in the United States alone.

"They often suffer from severe dyspareunia and are urged to refrain from using estrogen, which is the therapy most effective for dyspareunia in menopause," Dr. Goetsch said in an interview.

Furthermore, prior research has focused primarily on vaginal atrophy as the cause of dyspareunia in postmenopausal women.

"This study showed that pain could be prevented even though atrophy was unchanged," she said, noting that this suggests that perhaps atrophy is the wrong therapeutic focus.

"Success came with therapy to the vestibule, not the vagina," she said.

Dr. Goetsch reported having no disclosures.

Applying topical liquid lidocaine to the vulvar vestibule prior to penetration allows for comfortable intercourse in breast cancer survivors with severe menopausal dyspareunia, according to findings from a randomized, controlled study involving 46 women.

During a double-blind phase of the study, patients randomized to apply 4% aqueous lidocaine had less intercourse pain than those who applied saline (median pain scores of 1.0 and 5.3 out of 10, respectively), according to Dr. Martha F. Goetsch of Oregon Health and Science University, Portland, who will report the finding at the annual meeting of the American Congress of Obstetricians and Gynecologists.

During an open-label phase of the study in which all patients were allowed to apply lidocaine, 37 of 41 (90%) reported comfortable penetration, and sexual distress scores decreased from a median of 30.5 to a median of 14. Additionally, 17 of 20 women (85%) who were abstaining from intercourse because of the discomfort had resumed penetrative intimacy, said Dr. Goetsch, whose abstract was awarded first prize among oral presentations by ACOG.

Patients included in the study were estrogen-deficient breast cancer survivors with severe penetrative dyspareunia not associated with pelvic muscle or organ pain. All had severe vulvovaginal atrophy. During the 1-month blinded phase of the study, the women applied either the lidocaine or the saline to the vulvar vestibule for 3 minutes prior to penetration. Effects of twice-weekly tampon insertion or intercourse were documented in a diary. No partners complained of numbness resulting from the lidocaine.

The findings are notable, because breast cancer survivors number in the millions in the United States alone.

"They often suffer from severe dyspareunia and are urged to refrain from using estrogen, which is the therapy most effective for dyspareunia in menopause," Dr. Goetsch said in an interview.

Furthermore, prior research has focused primarily on vaginal atrophy as the cause of dyspareunia in postmenopausal women.

"This study showed that pain could be prevented even though atrophy was unchanged," she said, noting that this suggests that perhaps atrophy is the wrong therapeutic focus.

"Success came with therapy to the vestibule, not the vagina," she said.

Dr. Goetsch reported having no disclosures.

Women with twin pregnancies who have inadequate gestational weight gain during the second trimester have a more than twofold increase in the risk of preterm birth before 32 weeks, compared with those with adequate weight gain, findings from a retrospective cohort study suggest.

Inadequate weight gain between 20 and 28 weeks’ of gestation was the strongest predictor of preterm birth before 32 weeks in the study of 489 women with twin pregnancies, according to Dr. Kate E. Pettit, who will report the findings on Monday at the annual meeting of the American Congress of Obstetricians and Gynecologists in Chicago.

The rate of preterm birth prior to 32 weeks was 37.6% among women with inadequate weight gain during weeks 20-28, compared with 15.2% among those with adequate weight gain during that time period. Inadequate weight gain prior to 20 weeks was not associated with preterm birth, said Dr. Pettit of the University of California, San Diego, and her associates.

Other factors found to be associated with preterm birth in this study were monochorionicity and short cervical length, she noted.

All viable twin pregnancies delivered in the UCSD Health System between 2001 and 2013 were included in the study. Adequacy of weight gain was determined by dividing the minimum Institute of Medicine weight gain recommendation by 37 weeks.

"This study affirms the association between poor total gestational weight gain and preterm birth, and highlights the likely crucial period of time of 20-28 weeks of gestation that may be a target for future intervention trials," Dr. Pettit said in an interview.

The higher rate of preterm birth prior to 32 weeks’ of gestation among those with inadequate weight gain was attributable to spontaneous preterm birth, as there was no difference in the rates of indicated preterm birth among those with and without adequate weight gain, she explained, noting that "the biologic plausibility of the effect of gestational weight gain on the rate of spontaneous preterm birth is unknown."

"However, there is much room for improvement in gestational weight gain counseling, and a need for additional interventional trials to determine if adequacy of gestational weight gain at 20-28 weeks’ will, in fact, be one of the modifiable factors in the quest to reduce preterm birth in twin pregnancies," she said in an interview.

Interventions could include early goal-setting, nutritional assessment, and activity modification, she added.

Dr. Pettit reported having no disclosures.

Women with twin pregnancies who have inadequate gestational weight gain during the second trimester have a more than twofold increase in the risk of preterm birth before 32 weeks, compared with those with adequate weight gain, findings from a retrospective cohort study suggest.

Inadequate weight gain between 20 and 28 weeks’ of gestation was the strongest predictor of preterm birth before 32 weeks in the study of 489 women with twin pregnancies, according to Dr. Kate E. Pettit, who will report the findings on Monday at the annual meeting of the American Congress of Obstetricians and Gynecologists in Chicago.

The rate of preterm birth prior to 32 weeks was 37.6% among women with inadequate weight gain during weeks 20-28, compared with 15.2% among those with adequate weight gain during that time period. Inadequate weight gain prior to 20 weeks was not associated with preterm birth, said Dr. Pettit of the University of California, San Diego, and her associates.

Other factors found to be associated with preterm birth in this study were monochorionicity and short cervical length, she noted.

All viable twin pregnancies delivered in the UCSD Health System between 2001 and 2013 were included in the study. Adequacy of weight gain was determined by dividing the minimum Institute of Medicine weight gain recommendation by 37 weeks.

"This study affirms the association between poor total gestational weight gain and preterm birth, and highlights the likely crucial period of time of 20-28 weeks of gestation that may be a target for future intervention trials," Dr. Pettit said in an interview.

The higher rate of preterm birth prior to 32 weeks’ of gestation among those with inadequate weight gain was attributable to spontaneous preterm birth, as there was no difference in the rates of indicated preterm birth among those with and without adequate weight gain, she explained, noting that "the biologic plausibility of the effect of gestational weight gain on the rate of spontaneous preterm birth is unknown."

"However, there is much room for improvement in gestational weight gain counseling, and a need for additional interventional trials to determine if adequacy of gestational weight gain at 20-28 weeks’ will, in fact, be one of the modifiable factors in the quest to reduce preterm birth in twin pregnancies," she said in an interview.

Interventions could include early goal-setting, nutritional assessment, and activity modification, she added.

Dr. Pettit reported having no disclosures.

Women with twin pregnancies who have inadequate gestational weight gain during the second trimester have a more than twofold increase in the risk of preterm birth before 32 weeks, compared with those with adequate weight gain, findings from a retrospective cohort study suggest.

Inadequate weight gain between 20 and 28 weeks’ of gestation was the strongest predictor of preterm birth before 32 weeks in the study of 489 women with twin pregnancies, according to Dr. Kate E. Pettit, who will report the findings on Monday at the annual meeting of the American Congress of Obstetricians and Gynecologists in Chicago.

The rate of preterm birth prior to 32 weeks was 37.6% among women with inadequate weight gain during weeks 20-28, compared with 15.2% among those with adequate weight gain during that time period. Inadequate weight gain prior to 20 weeks was not associated with preterm birth, said Dr. Pettit of the University of California, San Diego, and her associates.

Other factors found to be associated with preterm birth in this study were monochorionicity and short cervical length, she noted.

All viable twin pregnancies delivered in the UCSD Health System between 2001 and 2013 were included in the study. Adequacy of weight gain was determined by dividing the minimum Institute of Medicine weight gain recommendation by 37 weeks.

"This study affirms the association between poor total gestational weight gain and preterm birth, and highlights the likely crucial period of time of 20-28 weeks of gestation that may be a target for future intervention trials," Dr. Pettit said in an interview.

The higher rate of preterm birth prior to 32 weeks’ of gestation among those with inadequate weight gain was attributable to spontaneous preterm birth, as there was no difference in the rates of indicated preterm birth among those with and without adequate weight gain, she explained, noting that "the biologic plausibility of the effect of gestational weight gain on the rate of spontaneous preterm birth is unknown."

"However, there is much room for improvement in gestational weight gain counseling, and a need for additional interventional trials to determine if adequacy of gestational weight gain at 20-28 weeks’ will, in fact, be one of the modifiable factors in the quest to reduce preterm birth in twin pregnancies," she said in an interview.

Interventions could include early goal-setting, nutritional assessment, and activity modification, she added.

Dr. Pettit reported having no disclosures.