Obstetrics

cfDNA screening failures occur in 1% to 12% of samples, a rate that has an inverse relationship to gestational age. Recent studies have shown an increased risk for screening failures among obese women. To determine the optimal gestational age for cfDNA testing among obese women, Mary C. Livergood, MD, and colleagues at the Mercy Hospital in St. Louis, Missouri, performed a retrospective cohort study of those undergoing cfDNA testing at one center from 2011 through 2016. Study results recently were published online in the American Journal of Obstetrics and Gynecology.¹

Details of the study

Adjusted odds ratios (aORs) with 95% confidence interval (CI) for a cfDNA screening failure (referred to as a “no call” in the study) were determined for each body mass index (BMI) weight class (TABLE). Each BMI weight class also was compared with the aOR of normal-weight women (BMI <25.0 kg/m²). The predicted probability of a no call was determined for each week of gestational age for normal weight and obese women and the results were compared.¹

Among the 2,385 patients meeting inclusion criteria, 4.4% (n = 105) received a no call. Compared with normal weight women, the aOR of no call increased as weight increased from overweight (aOR, 2.31 [95% CI, 1.21–4.42]) to obesity class III (aOR, 8.55 [95% CI, 4.16–17.56]).¹

At 21 weeks’ gestation, a cut-point was identified for obesity class II/III women (ie, there was no longer a significant difference in the probability of no call when compared with normal-weight women). From 8 to 16 weeks’ gestation, there was a 4.5% reduction in the probability of a no call for obesity class II/III women (aOR, 14.9; 95% CI, 8.95–20.78 and aOR, 10.4; 95% CI, 7.20–13.61; P_trend<.01).¹

Although the authors conclude that a cut-point of 21 weeks’ gestation allowed for optimal sampling of cfDNA in obese women, they also acknowledge that this cut-point limits a woman’s reproductive choices. However, they say that delaying cfDNA testing in obese women is a reasonable strategy to reduce the probability of screening failure.¹

cfDNA screening failures occur in 1% to 12% of samples, a rate that has an inverse relationship to gestational age. Recent studies have shown an increased risk for screening failures among obese women. To determine the optimal gestational age for cfDNA testing among obese women, Mary C. Livergood, MD, and colleagues at the Mercy Hospital in St. Louis, Missouri, performed a retrospective cohort study of those undergoing cfDNA testing at one center from 2011 through 2016. Study results recently were published online in the American Journal of Obstetrics and Gynecology.¹

Details of the study

Adjusted odds ratios (aORs) with 95% confidence interval (CI) for a cfDNA screening failure (referred to as a “no call” in the study) were determined for each body mass index (BMI) weight class (TABLE). Each BMI weight class also was compared with the aOR of normal-weight women (BMI <25.0 kg/m²). The predicted probability of a no call was determined for each week of gestational age for normal weight and obese women and the results were compared.¹

Among the 2,385 patients meeting inclusion criteria, 4.4% (n = 105) received a no call. Compared with normal weight women, the aOR of no call increased as weight increased from overweight (aOR, 2.31 [95% CI, 1.21–4.42]) to obesity class III (aOR, 8.55 [95% CI, 4.16–17.56]).¹

At 21 weeks’ gestation, a cut-point was identified for obesity class II/III women (ie, there was no longer a significant difference in the probability of no call when compared with normal-weight women). From 8 to 16 weeks’ gestation, there was a 4.5% reduction in the probability of a no call for obesity class II/III women (aOR, 14.9; 95% CI, 8.95–20.78 and aOR, 10.4; 95% CI, 7.20–13.61; P_trend<.01).¹

Although the authors conclude that a cut-point of 21 weeks’ gestation allowed for optimal sampling of cfDNA in obese women, they also acknowledge that this cut-point limits a woman’s reproductive choices. However, they say that delaying cfDNA testing in obese women is a reasonable strategy to reduce the probability of screening failure.¹

cfDNA screening failures occur in 1% to 12% of samples, a rate that has an inverse relationship to gestational age. Recent studies have shown an increased risk for screening failures among obese women. To determine the optimal gestational age for cfDNA testing among obese women, Mary C. Livergood, MD, and colleagues at the Mercy Hospital in St. Louis, Missouri, performed a retrospective cohort study of those undergoing cfDNA testing at one center from 2011 through 2016. Study results recently were published online in the American Journal of Obstetrics and Gynecology.¹

Details of the study

Adjusted odds ratios (aORs) with 95% confidence interval (CI) for a cfDNA screening failure (referred to as a “no call” in the study) were determined for each body mass index (BMI) weight class (TABLE). Each BMI weight class also was compared with the aOR of normal-weight women (BMI <25.0 kg/m²). The predicted probability of a no call was determined for each week of gestational age for normal weight and obese women and the results were compared.¹

Among the 2,385 patients meeting inclusion criteria, 4.4% (n = 105) received a no call. Compared with normal weight women, the aOR of no call increased as weight increased from overweight (aOR, 2.31 [95% CI, 1.21–4.42]) to obesity class III (aOR, 8.55 [95% CI, 4.16–17.56]).¹

At 21 weeks’ gestation, a cut-point was identified for obesity class II/III women (ie, there was no longer a significant difference in the probability of no call when compared with normal-weight women). From 8 to 16 weeks’ gestation, there was a 4.5% reduction in the probability of a no call for obesity class II/III women (aOR, 14.9; 95% CI, 8.95–20.78 and aOR, 10.4; 95% CI, 7.20–13.61; P_trend<.01).¹

Although the authors conclude that a cut-point of 21 weeks’ gestation allowed for optimal sampling of cfDNA in obese women, they also acknowledge that this cut-point limits a woman’s reproductive choices. However, they say that delaying cfDNA testing in obese women is a reasonable strategy to reduce the probability of screening failure.¹

Early elective delivery in the United States is at an all-time low of 1.9%, down from 17% in 2010, according to a report by a nonprofit group that monitors safety and care quality in hospitals.

Early elective delivery comprises Cesarean deliveries or inductions performed before 39 weeks without medical necessity, and higher rates are considered a barometer of poor labor management in hospitals. For its annual report on maternity practices, published Feb. 28, the Leapfrog Group, a Washington, D.C.–based nonprofit, collected voluntarily reported data from 1,859 hospitals, or about half of the nation’s hospitals, in 2016.

monkeybusinessimages/Thinkstock

Early elective delivery in the United States is at an all-time low of 1.9%, down from 17% in 2010, according to a report by a nonprofit group that monitors safety and care quality in hospitals.

Early elective delivery comprises Cesarean deliveries or inductions performed before 39 weeks without medical necessity, and higher rates are considered a barometer of poor labor management in hospitals. For its annual report on maternity practices, published Feb. 28, the Leapfrog Group, a Washington, D.C.–based nonprofit, collected voluntarily reported data from 1,859 hospitals, or about half of the nation’s hospitals, in 2016.

monkeybusinessimages/Thinkstock

Early elective delivery in the United States is at an all-time low of 1.9%, down from 17% in 2010, according to a report by a nonprofit group that monitors safety and care quality in hospitals.

Early elective delivery comprises Cesarean deliveries or inductions performed before 39 weeks without medical necessity, and higher rates are considered a barometer of poor labor management in hospitals. For its annual report on maternity practices, published Feb. 28, the Leapfrog Group, a Washington, D.C.–based nonprofit, collected voluntarily reported data from 1,859 hospitals, or about half of the nation’s hospitals, in 2016.

monkeybusinessimages/Thinkstock

LAS VEGAS – Certain cervicovaginal microbiota predispose women to spontaneous preterm birth, according to a new study, while other microbiota were found to be protective against preterm delivery.

The findings stand in contrast to previous clinical trials that “targeted uterine activity and/or uterine infection,” said Michal Elovitz, MD, the first author of a study presented at the annual Pregnancy Meeting sponsored by the Society for Maternal-Fetal Medicine.

[email protected]

On Twitter @karioakes

LAS VEGAS – Certain cervicovaginal microbiota predispose women to spontaneous preterm birth, according to a new study, while other microbiota were found to be protective against preterm delivery.

The findings stand in contrast to previous clinical trials that “targeted uterine activity and/or uterine infection,” said Michal Elovitz, MD, the first author of a study presented at the annual Pregnancy Meeting sponsored by the Society for Maternal-Fetal Medicine.

[email protected]

On Twitter @karioakes

LAS VEGAS – Certain cervicovaginal microbiota predispose women to spontaneous preterm birth, according to a new study, while other microbiota were found to be protective against preterm delivery.

The findings stand in contrast to previous clinical trials that “targeted uterine activity and/or uterine infection,” said Michal Elovitz, MD, the first author of a study presented at the annual Pregnancy Meeting sponsored by the Society for Maternal-Fetal Medicine.

[email protected]

On Twitter @karioakes

ORLANDO – Pregnancy prevention remains a challenge when prescribing isotretinoin to women of childbearing years with acne, Megha M. Tollefson, MD, said at the annual meeting of the American Academy of Dermatology.

Like so many promises having to do with love, a promise of sexual abstinence, however earnest, may at some point fall by the wayside, said Dr. Tollefson of the Mayo Clinic, Rochester, Minn., in a video interview.

ORLANDO – Pregnancy prevention remains a challenge when prescribing isotretinoin to women of childbearing years with acne, Megha M. Tollefson, MD, said at the annual meeting of the American Academy of Dermatology.

Like so many promises having to do with love, a promise of sexual abstinence, however earnest, may at some point fall by the wayside, said Dr. Tollefson of the Mayo Clinic, Rochester, Minn., in a video interview.

ORLANDO – Pregnancy prevention remains a challenge when prescribing isotretinoin to women of childbearing years with acne, Megha M. Tollefson, MD, said at the annual meeting of the American Academy of Dermatology.

Like so many promises having to do with love, a promise of sexual abstinence, however earnest, may at some point fall by the wayside, said Dr. Tollefson of the Mayo Clinic, Rochester, Minn., in a video interview.

ATLANTA – Increasing maternal postpartum–plasma alpha-tocopherol isoform concentration was associated with a decreased likelihood of wheezing at age 2 years, defined as wheezing in the past 12 months, use of asthma medications in the past 12 months, or diagnosis of asthma, results from a large analysis showed.

“For now, this is an association and not causation,” study author Cosby Stone, MD, MPH, said in an interview in advance of the annual meeting of the American Academy of Allergy, Asthma, and Immunology. “We need a clinical trial to evaluate the effect of giving more alpha-tocopherol to mothers during pregnancy before anyone should jump to giving supplements.”

[email protected]

ATLANTA – Increasing maternal postpartum–plasma alpha-tocopherol isoform concentration was associated with a decreased likelihood of wheezing at age 2 years, defined as wheezing in the past 12 months, use of asthma medications in the past 12 months, or diagnosis of asthma, results from a large analysis showed.

“For now, this is an association and not causation,” study author Cosby Stone, MD, MPH, said in an interview in advance of the annual meeting of the American Academy of Allergy, Asthma, and Immunology. “We need a clinical trial to evaluate the effect of giving more alpha-tocopherol to mothers during pregnancy before anyone should jump to giving supplements.”

[email protected]

ATLANTA – Increasing maternal postpartum–plasma alpha-tocopherol isoform concentration was associated with a decreased likelihood of wheezing at age 2 years, defined as wheezing in the past 12 months, use of asthma medications in the past 12 months, or diagnosis of asthma, results from a large analysis showed.

“For now, this is an association and not causation,” study author Cosby Stone, MD, MPH, said in an interview in advance of the annual meeting of the American Academy of Allergy, Asthma, and Immunology. “We need a clinical trial to evaluate the effect of giving more alpha-tocopherol to mothers during pregnancy before anyone should jump to giving supplements.”

[email protected]

Birth defects potentially linked to cases of Zika virus in the United States have increased by a factor of nearly 20 since the virus first made its way into the country, according to new findings by the Centers for Disease Control and Prevention.

“The higher proportion of these defects among pregnancies with laboratory evidence of Zika infection in USZPR [U.S. Zika Pregnancy Registry] supports the relationship between congenital Zika virus infection and these birth defects,” wrote the authors of a new report led by Janet D. Cragan, MD, of the National Center on Birth Defects and Developmental Disabilities at the CDC (MMWR Morb Mortal Wkly Rep. 2017;66:219-22).

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Dr. Cragan and her coauthors retrospectively examined data on birth defects in three regions of the country: Massachusetts during 2013, North Carolina during 2013, and Atlanta during 2013-2014. The investigators focused on birth defects associated with prenatal Zika virus infections, mainly brain abnormalities and microcephaly.

The rate of total birth defects across the three regions was 2.86 per 1,000 live births, with 747 infants and fetuses identified as having one or more defects. Microcephaly and brain abnormalities alone occurred at a rate of 1.50 per 1,000 live births, with eye abnormalities and central nervous system dysfunction also occurring.

These numbers are relatively low when compared with data from Jan. 15 through Sept. 22, 2016. The birth defect rate jumped up to 58.8 per 1,000 live births, according to data from the USZPR, which found evidence of 26 infants and fetuses with brain or cranial defects in 442 completed pregnancies. These infants were all born to mothers with laboratory-confirmed Zika virus infections.

“Among 410 (55%) infants or fetuses with information on the earliest age a birth defect was recorded, 371 (90%) had evidence of a birth defect meeting the Zika definition before age 3 months,” the authors explained. “More than half of those with brain abnormalities or microcephaly or with neural tube defects and other early brain malformations had evidence of these defects noted prenatally (55% and 89%, respectively).”

Dr. Cragan and her colleagues hope that this evidence will further solidify the link between Zika virus and birth defects and pave the way for more population-based studies.

“These data demonstrate the critical contribution of population-based birth defects surveillance to understanding the impact of Zika virus infection during pregnancy,” the authors concluded. “In 2016, CDC provided funding for 45 local, state, and territorial health departments to conduct rapid population-based surveillance for defects potentially related to Zika virus infection, which will provide essential data to monitor the impact of Zika virus infection in the United States.”

[email protected]

Birth defects potentially linked to cases of Zika virus in the United States have increased by a factor of nearly 20 since the virus first made its way into the country, according to new findings by the Centers for Disease Control and Prevention.

“The higher proportion of these defects among pregnancies with laboratory evidence of Zika infection in USZPR [U.S. Zika Pregnancy Registry] supports the relationship between congenital Zika virus infection and these birth defects,” wrote the authors of a new report led by Janet D. Cragan, MD, of the National Center on Birth Defects and Developmental Disabilities at the CDC (MMWR Morb Mortal Wkly Rep. 2017;66:219-22).

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Dr. Cragan and her coauthors retrospectively examined data on birth defects in three regions of the country: Massachusetts during 2013, North Carolina during 2013, and Atlanta during 2013-2014. The investigators focused on birth defects associated with prenatal Zika virus infections, mainly brain abnormalities and microcephaly.

The rate of total birth defects across the three regions was 2.86 per 1,000 live births, with 747 infants and fetuses identified as having one or more defects. Microcephaly and brain abnormalities alone occurred at a rate of 1.50 per 1,000 live births, with eye abnormalities and central nervous system dysfunction also occurring.

These numbers are relatively low when compared with data from Jan. 15 through Sept. 22, 2016. The birth defect rate jumped up to 58.8 per 1,000 live births, according to data from the USZPR, which found evidence of 26 infants and fetuses with brain or cranial defects in 442 completed pregnancies. These infants were all born to mothers with laboratory-confirmed Zika virus infections.

“Among 410 (55%) infants or fetuses with information on the earliest age a birth defect was recorded, 371 (90%) had evidence of a birth defect meeting the Zika definition before age 3 months,” the authors explained. “More than half of those with brain abnormalities or microcephaly or with neural tube defects and other early brain malformations had evidence of these defects noted prenatally (55% and 89%, respectively).”

Dr. Cragan and her colleagues hope that this evidence will further solidify the link between Zika virus and birth defects and pave the way for more population-based studies.

“These data demonstrate the critical contribution of population-based birth defects surveillance to understanding the impact of Zika virus infection during pregnancy,” the authors concluded. “In 2016, CDC provided funding for 45 local, state, and territorial health departments to conduct rapid population-based surveillance for defects potentially related to Zika virus infection, which will provide essential data to monitor the impact of Zika virus infection in the United States.”

[email protected]

Birth defects potentially linked to cases of Zika virus in the United States have increased by a factor of nearly 20 since the virus first made its way into the country, according to new findings by the Centers for Disease Control and Prevention.

“The higher proportion of these defects among pregnancies with laboratory evidence of Zika infection in USZPR [U.S. Zika Pregnancy Registry] supports the relationship between congenital Zika virus infection and these birth defects,” wrote the authors of a new report led by Janet D. Cragan, MD, of the National Center on Birth Defects and Developmental Disabilities at the CDC (MMWR Morb Mortal Wkly Rep. 2017;66:219-22).

[[{"attributes":{},"fields":{}}]]

Dr. Cragan and her coauthors retrospectively examined data on birth defects in three regions of the country: Massachusetts during 2013, North Carolina during 2013, and Atlanta during 2013-2014. The investigators focused on birth defects associated with prenatal Zika virus infections, mainly brain abnormalities and microcephaly.

The rate of total birth defects across the three regions was 2.86 per 1,000 live births, with 747 infants and fetuses identified as having one or more defects. Microcephaly and brain abnormalities alone occurred at a rate of 1.50 per 1,000 live births, with eye abnormalities and central nervous system dysfunction also occurring.

These numbers are relatively low when compared with data from Jan. 15 through Sept. 22, 2016. The birth defect rate jumped up to 58.8 per 1,000 live births, according to data from the USZPR, which found evidence of 26 infants and fetuses with brain or cranial defects in 442 completed pregnancies. These infants were all born to mothers with laboratory-confirmed Zika virus infections.

“Among 410 (55%) infants or fetuses with information on the earliest age a birth defect was recorded, 371 (90%) had evidence of a birth defect meeting the Zika definition before age 3 months,” the authors explained. “More than half of those with brain abnormalities or microcephaly or with neural tube defects and other early brain malformations had evidence of these defects noted prenatally (55% and 89%, respectively).”

Dr. Cragan and her colleagues hope that this evidence will further solidify the link between Zika virus and birth defects and pave the way for more population-based studies.

“These data demonstrate the critical contribution of population-based birth defects surveillance to understanding the impact of Zika virus infection during pregnancy,” the authors concluded. “In 2016, CDC provided funding for 45 local, state, and territorial health departments to conduct rapid population-based surveillance for defects potentially related to Zika virus infection, which will provide essential data to monitor the impact of Zika virus infection in the United States.”

[email protected]

The American College of Obstetricians and Gynecologists is calling on ob.gyns. to establish a standard carrier screening process that is consistently offered to all patients before pregnancy.

This a shift from previous ACOG policy, which recommended carrier screening based mainly on ethnicity.

In a pair of opinions from ACOG’s Committee on Genetics, they highlighted three acceptable screening methods: ethnic-specific screening, panethnic screening, and expanded-carrier screening (Obstet Gynecol. 2017;129:e35-40/Obstet Gynecol. 2017;129:e41-55).

Panethnic and expanded-carrier screening are especially helpful for patients with parents of different ethnic backgrounds or those who do not know their family history, situations that have become more common.

• Test only for diseases with a carrier frequency of 1 in 100 or greater, have a well-defined phenotype, have a detrimental effect on quality of life, cause cognitive or physical impairment, require surgical or medical intervention, or have an onset early in life.
• All patients, regardless of screening strategy and ethnicity, should be checked for cystic fibrosis and spinal muscular atrophy, and also undergo a complete blood count and screening for thalassemias and hemoglobinopathies.
• Prenatal carrier screening does not replace newborn screening, and at the same time, newborn screening does not diminish the potential benefits of prenatal carrier screening.

“Practitioners should be testing patients for these diseases as early as possible,” Dr. Biggio said. “A consistent approach to screening consultation will help with that immensely.”

[email protected]

On Twitter @EAZTweets

The American College of Obstetricians and Gynecologists is calling on ob.gyns. to establish a standard carrier screening process that is consistently offered to all patients before pregnancy.

This a shift from previous ACOG policy, which recommended carrier screening based mainly on ethnicity.

In a pair of opinions from ACOG’s Committee on Genetics, they highlighted three acceptable screening methods: ethnic-specific screening, panethnic screening, and expanded-carrier screening (Obstet Gynecol. 2017;129:e35-40/Obstet Gynecol. 2017;129:e41-55).

Panethnic and expanded-carrier screening are especially helpful for patients with parents of different ethnic backgrounds or those who do not know their family history, situations that have become more common.

• Test only for diseases with a carrier frequency of 1 in 100 or greater, have a well-defined phenotype, have a detrimental effect on quality of life, cause cognitive or physical impairment, require surgical or medical intervention, or have an onset early in life.
• All patients, regardless of screening strategy and ethnicity, should be checked for cystic fibrosis and spinal muscular atrophy, and also undergo a complete blood count and screening for thalassemias and hemoglobinopathies.
• Prenatal carrier screening does not replace newborn screening, and at the same time, newborn screening does not diminish the potential benefits of prenatal carrier screening.

“Practitioners should be testing patients for these diseases as early as possible,” Dr. Biggio said. “A consistent approach to screening consultation will help with that immensely.”

[email protected]

On Twitter @EAZTweets

The American College of Obstetricians and Gynecologists is calling on ob.gyns. to establish a standard carrier screening process that is consistently offered to all patients before pregnancy.

This a shift from previous ACOG policy, which recommended carrier screening based mainly on ethnicity.

In a pair of opinions from ACOG’s Committee on Genetics, they highlighted three acceptable screening methods: ethnic-specific screening, panethnic screening, and expanded-carrier screening (Obstet Gynecol. 2017;129:e35-40/Obstet Gynecol. 2017;129:e41-55).

Panethnic and expanded-carrier screening are especially helpful for patients with parents of different ethnic backgrounds or those who do not know their family history, situations that have become more common.

• Test only for diseases with a carrier frequency of 1 in 100 or greater, have a well-defined phenotype, have a detrimental effect on quality of life, cause cognitive or physical impairment, require surgical or medical intervention, or have an onset early in life.
• All patients, regardless of screening strategy and ethnicity, should be checked for cystic fibrosis and spinal muscular atrophy, and also undergo a complete blood count and screening for thalassemias and hemoglobinopathies.
• Prenatal carrier screening does not replace newborn screening, and at the same time, newborn screening does not diminish the potential benefits of prenatal carrier screening.

“Practitioners should be testing patients for these diseases as early as possible,” Dr. Biggio said. “A consistent approach to screening consultation will help with that immensely.”

[email protected]

On Twitter @EAZTweets

Over the last decade, appreciation of the prevalence of perinatal depression – depression during pregnancy and/or the postpartum period – along with interest and willingness to diagnose and to treat these disorders across primary care, obstetric, and psychiatric clinical settings – has grown.

The passage of the Affordable Care Act in 2010 included the Melanie Blocker Stokes MOTHERS Act, which provides federal funding for programs to enhance awareness of postpartum depression and conduct research into its causes and treatment. At the same time, there has been increasing destigmatization associated with perinatal mood and anxiety disorders across many communities, and enhanced knowledge among clinicians and the public regarding evidence-based treatments, which mitigate suffering from untreated perinatal psychiatric illness.

Dr. Cohen is the director of the Center for Women’s Mental Health at Massachusetts General Hospital in Boston, which provides information resources and conducts clinical care and research in reproductive mental health. He has been a consultant to manufacturers of psychiatric medications.

Over the last decade, appreciation of the prevalence of perinatal depression – depression during pregnancy and/or the postpartum period – along with interest and willingness to diagnose and to treat these disorders across primary care, obstetric, and psychiatric clinical settings – has grown.

The passage of the Affordable Care Act in 2010 included the Melanie Blocker Stokes MOTHERS Act, which provides federal funding for programs to enhance awareness of postpartum depression and conduct research into its causes and treatment. At the same time, there has been increasing destigmatization associated with perinatal mood and anxiety disorders across many communities, and enhanced knowledge among clinicians and the public regarding evidence-based treatments, which mitigate suffering from untreated perinatal psychiatric illness.

Dr. Cohen is the director of the Center for Women’s Mental Health at Massachusetts General Hospital in Boston, which provides information resources and conducts clinical care and research in reproductive mental health. He has been a consultant to manufacturers of psychiatric medications.

Over the last decade, appreciation of the prevalence of perinatal depression – depression during pregnancy and/or the postpartum period – along with interest and willingness to diagnose and to treat these disorders across primary care, obstetric, and psychiatric clinical settings – has grown.

The passage of the Affordable Care Act in 2010 included the Melanie Blocker Stokes MOTHERS Act, which provides federal funding for programs to enhance awareness of postpartum depression and conduct research into its causes and treatment. At the same time, there has been increasing destigmatization associated with perinatal mood and anxiety disorders across many communities, and enhanced knowledge among clinicians and the public regarding evidence-based treatments, which mitigate suffering from untreated perinatal psychiatric illness.

Dr. Cohen is the director of the Center for Women’s Mental Health at Massachusetts General Hospital in Boston, which provides information resources and conducts clinical care and research in reproductive mental health. He has been a consultant to manufacturers of psychiatric medications.

Umbilical cord blood (cord) gas values can aid both in understanding the cause of an infant’s acidosis and in providing reassurance that acute acidosis or asphyxia is not responsible for a compromised infant with a low Apgar score. Together with other clinical measurements (including fetal heart rate [FHR] tracings, Apgar scores, newborn nucleated red cell counts, and neonatal imaging), cord gas analysis can be remarkably helpful in determining the cause for a depressed newborn. It can help us determine, for example, if infant compromise was a result of an asphyxial event, and we often can differentiate whether the event was acute, prolonged, or occurred prior to presentation in labor. We further can use cord gas values to assess whether a decision for operative intervention for nonreassuring fetal well-being was appropriate (see “Brain injury at birth: Cord gas values presented as evidence at trial”). In addition, cord gas analysis can complement methods for determining fetal acidosis changes during labor, enabling improved assessment of FHR tracings.¹⁻³

I recommend checking umbilical cord blood gas values on all operative vaginal deliveries, cesarean deliveries for fetal concern, abnormal FHR patterns, clinical chorioamnionitis, multifetal gestations, premature deliveries, and all infants with low Apgar scores at 1 or 5 minutes. If you think you may need a cord gas analysis, go ahead and obtain it. Cord gas analysis often will aid in justifying your management or provide insight into the infant’s status.

Controversy remains as to the benefit of universal cord gas analysis. Assuming a variable cost of $15 for 2 (artery and vein) blood gas samples per neonate,⁴ the annual cost in the United States would be approximately $60 million. This would likely be cost effective as a result of medicolegal and educational benefits as well as potential improvements in perinatal outcome⁵ and reductions in special care nursery admissions.⁴

CASE 1: A newborn with unexpected acidosis

A 29-year-old woman (G2P1) at 38 weeks’ gestation was admitted to the hospital following an office visit during which oligohydramnios (amniotic fluid index, 3.5 cm) was found. The patient had a history of a prior cesarean delivery for failure to progress, and she desired a repeat cesarean delivery. Fetal monitoring revealed a heart rate of 140 beats per minute with moderate variability and uterine contractions every 3 to 5 minutes associated with moderate variable decelerations. A decision was made to proceed with the surgery. Blood samples were drawn for laboratory analysis, monitoring was discontinued, and the patient was taken to the operating room. An epidural anesthetic was placed and the cesarean delivery proceeded.

On uterine incision, there was no evidence of abruption or uterine rupture, but thick meconium-stained amniotic fluid was observed. A depressed infant was delivered, the umbilical cord clamped, and the infant handed to the pediatric team. Cord samples were obtained and values from the umbilical artery were as follows: pH, 6.80; Pco₂, 120 mm Hg; Po₂, 6 mm Hg; and base deficit extracellular fluid (BD_ECF), 13.8 mmol/L. Values from the umbilical vein were: pH, 7.32; Pco₂, 38 mm Hg; Po₂, 22 mm Hg; and BD_ECF, 5.8 mmol/L. The infant’s Apgar scores were 1, 2, and 7 at 1, 5, and 10 minutes, respectively, and the infant demonstrated encephalopathy, requiring brain cooling.

What happened?

Read how to use cord gas values in practice

Using cord gas values in practice

Before analyzing the circumstances in Case 1,it is important to consider several key questions, including:

• What are the normal levels of cord pH, O₂, CO₂, and base deficit (BD)?
• How does cord gas indicate what happened during labor?
• What are the preventable errors in cord gas sampling or interpretation?

For a review of fetal cord gas physiology, see “Physiology of fetal cord gases: The basics”.

Normal values: The “20, 30, 40, 50 rule”

Among the values reported for umbilical blood gas, the pH, Pco₂, and Po₂ are measured, whereas BD is calculated. The normal values for umbilical pH and blood gases are often included with laboratory results, although typically with a broad, overlapping range of values that may make it difficult to determine which is umbilical artery or vein (TABLE 1).^6,7

I recommend using the “20, 30, 40, 50 rule” as a simple tool for remembering normal umbilical artery and vein Po₂ and Pco₂ values (TABLE 2):

• Po₂ values are lower than Pco₂ values; thus, the 20 and 30 represent Po₂ values
• as fetal umbilical artery Po₂ is lower than umbilical vein Po₂, 20 mm Hg represents the umbilical artery and 30 mm Hg represents the vein
• Pco₂ values are higher in the umbilical artery than in the vein; thus, 50 mm Hg represents the umbilical artery and 40 mm Hg represents the umbilical vein.

Umbilical cord BD values change in relation to labor and FHR decelerations.⁸ Prior to labor, the normal fetus has a slight degree of acidosis (BD, 2 mmol/L). During the latent phase of labor, fetal BD typically does not change. With the increased frequency of contractions, BD may increase 1 mmol/L for every 3 to 6 hours during the active phase and up to 1 mmol/L per hour during the second stage, depending on FHR responses. Thus, following vaginal delivery the average umbilical artery BD is approximately 5 mmol/L and the umbilical vein BD is approximately 4 mmol/L. As lactate crosses the placenta slowly, BD values are typically only 1 mmol/L less in the umbilical vein than in the artery, unless there has been an obstruction to placental flow (see Case 1).

For pH, the umbilical artery value is always lower than that of the vein, a result of both the higher umbilical artery Pco₂ as well as the slightly higher levels of lactic acid before placental clearance. Fetal pH levels typically decrease during labor associated with the increased BD described above. However, short-term effects of increased CO₂ (respiratory acidosis) or CO₂ clearance may cause fluctuations in pH that do not correlate with the degree of metabolic acidosis.

Possible causes of abnormal cord gas values

Because of the nearly fully saturated maternal hemoglobin under normal conditions, fetal arterial and venous Po₂ levels cannot be increased significantly above normal values. However, reduced fetal Po₂ and increased fetal Pco₂ may occur with poor gas exchange between the maternal and fetal compartments (eg, placental abruption) or maternal respiratory compromise.

In contrast, reduced fetal Pco₂ may occur under conditions of maternal hyperventilation and lower maternal Pco₂ values. Decreased pH levels may be due to respiratory or metabolic acidosis, the former of which is generally benign. Elevated BD typically is a result of fetal metabolic acidosis, and values approaching 12 mmol/L should be avoided, if possible, as this level may be associated with newborn neurologic injury.⁹

Effect of maternal oxygen administration on fetal oxygenation

Although maternal oxygen administration is commonly used during labor and delivery, controversy remains as to the benefit of oxygen supplementation.¹⁰ In a normal mother with oxygen saturation above 95%, the administration of oxygen will increase maternal arterial Po₂ levels and thus dissolved oxygen. Because maternal hemoglobin is normally almost fully saturated at room air Po₂ levels, there is little change in the bound oxygen and thus little change in the maternal arterial O₂ content or maternal uterine venous Po₂ levels. As fetal umbilical vein Po₂ levels equilibrate to maternal uterine vein Po₂ levels, there is minimal change in fetal oxygenation.

However, maternal oxygen supplementation may have marked benefit in cases in which maternal arterial Po₂ is low (respiratory compromise). In this case, the steep fetal oxygen saturation curve may produce a large increase in fetal umbilical vein oxygen content. Thus, strongly consider oxygen supplementation for mothers with impaired cardiorespiratory function, and recognize that maternal oxygen supplementation for normal mothers may result in nominal benefit for compromised fetuses.

How did the Case 1 circumstances lead to newborn acidosis?

Most noticeable in this case is the large difference in BD between the umbilical artery and vein and the high Pco₂in the artery. Under conditions without interruption of fetal placental flow, either the umbilical artery and/or vein will provide a similar assessment of fetal or newborn metabolic acidosis (that is, BD).

Whereas BD normally is only about 1 mmol/L greater in the umbilical artery versus in the vein, occasionally the arterial value is markedly greater than the vein value. This can occur when there is a cessation of blood flow through the placenta, as a result of complete umbilical cord obstruction, or when there is a uterine abruption. In these situations, the umbilical vein (which has not had blood flow) represents the fetal status prior to the occlusion event. In contrast, despite bradycardia, fetal heart pulsations mix blood within the umbilical artery and therefore the artery generally represents the fetal status at the time of birth.

In response to complete cord occlusion, fetal BD increases by approximately 1 mmol/L every 2 minutes. Consequently, an 8 mmol/L difference in BD between the umbilical artery and vein is consistent with a 16-minute period of umbilical occlusion or placental abruption. Also in response to complete umbilical cord occlusion, Pco₂ values rise by approximately 7 mm Hg per minute of the occlusion, although this may not be linear at higher levels. Thus, the BD difference suggests there was likely a complete cord occlusion for the 16 minutes prior to birth.

The umbilical vein BD is also elevated for early labor. This value suggests that repetitive, intermittent cord occlusions (evident on the initial fetal monitor tracing) likely resulted in this moderate acidosis prior to the complete cord occlusion in the final 16 minutes.

Thus, BD and Pco₂ levels can be used to time the onset of umbilical cord occlusion or abruption. Since pH is an inverse logarithmic function, it cannot be used to time the onset or duration of cord occlusion. Remember that BD values should be adjusted for extracellular fluid under conditions of markedly elevated Pco₂.

Read more cases plus procedures, equipment for cord sampling

Illustration: Kimberly Martens for OBG Management

CASE 2: An infant with unusual umbilical artery values

An infant born via vacuum delivery for a prolonged second stage of labor had 1- and 5-minute Apgar scores of 8 and 9, respectively. Cord gas values were obtained, and analysis revealed that for the umbilical artery, the pH was 7.29; Pco₂, 20 mm Hg; and Po₂, 60 mm Hg. For the umbilical vein, the pH was 7.32; Pco₂, 38 mm Hg; and Po₂, 22 mm Hg.

The resident asked, “How is the Po₂ higher in the artery than in the vein?”

The curious Case 2 values suggest an air bubble

Although it is possible that the aberrant values in Case 2 could have resulted from switching the artery and vein samples, the pH is lower in the artery, and both the artery Po₂ and Pco₂ levels do not appear physiologic. The likely explanation for these values is that an air bubble was contained in the syringe. Since normal room air (21% O₂) has a Po₂ of 159 mm Hg and a Pco₂ of less than 1 mm Hg, exposure of cord blood gases to air bubbles will significantly increase the Po₂ and markedly reduce the Pco₂ values of the sample. Take care to avoid air bubbles in the syringes used to obtain samples for analysis.

Related article:
Is neonatal injury more likely outside of a 30-minute decision-to-incision time interval for cesarean delivery?

CASE 3: A vigorous baby with significant acidosis

A baby with 1- and 5-minute Apgar scores of 9 and 9 was delivered by cesarean and remained vigorous. Umbilical cord analysis revealed an umbilical artery pH level of 7.15, with normal Po₂ and Pco₂ values. What could be the explanation?

Was there a collection error in Case 3?

On occasion, a falsely low pH level and, thus, a falsely elevated BD may result from excessive heparin in the collection syringe. Heparin is acidotic and should be used only to coat the syringe. Although syringes in current use are often pre-heparinized, if one is drawing up heparin into the syringe, it should be coated and then fully expelled.

Umbilical cord sampling: Procedures and equipment

Many issues remain regarding the optimal storage of cord samples. Ideally, a doubly clamped section of the cord promptly should be sampled into glass syringes that can be placed on ice and rapidly measured for cord values.

Stability of umbilical cord samples within the cord is within 20 to 30 minutes. Delayed sampling of clamped cord sections generally has minimal effect on pH and Pco₂ values.¹¹ The BD does not change to a clinically significant degree over 15 to 30 minutes despite the cord specimen remaining at room temperature. However, one report demonstrated an increase in lactate and BD by 20 minutes under these conditions; this likely was a result of metabolism from endothelial or blood cells.¹² I therefore recommend that clamped cord be sampled as soon as is feasible and ideally not beyond 20 to 30 minutes.

Plastic syringes can introduce interference. Several studies have demonstrated that collection of samples in plastic may result in an increase in Po₂ values, likely due to the high room air Po₂ diffusing through the plastic to the blood sample.

Use glass, and “ice” the sample if necessary. Although it has been suggested that placing samples on ice minimizes metabolism, the cooled plastic may in fact be more susceptible to oxygen diffusion. Thus, unless samples will be analyzed promptly, it is best to use glass syringes on ice.^13,14

Related article:
Protecting the newborn brain—the final frontier in obstetric and neonatal care

What if the umbilical cord is torn?

Sometimes the umbilical cord is torn and discarded or cannot be accessed for other reasons. A sample can still be obtained, however, by aspirating the placental surface artery and vein vessels. Although there is some potential variance in pH, Po₂, and Pco₂ levels, the BD values of placental vessels have a high correlation with those of umbilical vessels and therefore can be used when the cord is not available.¹⁵

How do you obtain cord analysis when delaying cord clamping?

The American College of Obstetricians and Gynecologists (ACOG) now advises delayed cord clamping in term and preterm deliveries, which raises the question of how you obtain a blood sample in this setting. Importantly, ACOG recommends delayed cord clamping only in vigorous infants,¹⁶ whereas potentially compromised infants should be transferred rapidly for newborn care. Although several studies have demonstrated some variation in cord gas values with delayed cord clamping,^17–21 clamping after pulsation has ceased or after the recommended 30 to 60 seconds following birth results in minimal change in BD values. Thus, do not hesitate to perform delayed cord clamping in vigorous infants.

Share your thoughts! Send your Letter to the Editor to [email protected]. Please include your name and the city and state in which you practice.

Umbilical cord blood (cord) gas values can aid both in understanding the cause of an infant’s acidosis and in providing reassurance that acute acidosis or asphyxia is not responsible for a compromised infant with a low Apgar score. Together with other clinical measurements (including fetal heart rate [FHR] tracings, Apgar scores, newborn nucleated red cell counts, and neonatal imaging), cord gas analysis can be remarkably helpful in determining the cause for a depressed newborn. It can help us determine, for example, if infant compromise was a result of an asphyxial event, and we often can differentiate whether the event was acute, prolonged, or occurred prior to presentation in labor. We further can use cord gas values to assess whether a decision for operative intervention for nonreassuring fetal well-being was appropriate (see “Brain injury at birth: Cord gas values presented as evidence at trial”). In addition, cord gas analysis can complement methods for determining fetal acidosis changes during labor, enabling improved assessment of FHR tracings.¹⁻³

I recommend checking umbilical cord blood gas values on all operative vaginal deliveries, cesarean deliveries for fetal concern, abnormal FHR patterns, clinical chorioamnionitis, multifetal gestations, premature deliveries, and all infants with low Apgar scores at 1 or 5 minutes. If you think you may need a cord gas analysis, go ahead and obtain it. Cord gas analysis often will aid in justifying your management or provide insight into the infant’s status.

Controversy remains as to the benefit of universal cord gas analysis. Assuming a variable cost of $15 for 2 (artery and vein) blood gas samples per neonate,⁴ the annual cost in the United States would be approximately $60 million. This would likely be cost effective as a result of medicolegal and educational benefits as well as potential improvements in perinatal outcome⁵ and reductions in special care nursery admissions.⁴

CASE 1: A newborn with unexpected acidosis

A 29-year-old woman (G2P1) at 38 weeks’ gestation was admitted to the hospital following an office visit during which oligohydramnios (amniotic fluid index, 3.5 cm) was found. The patient had a history of a prior cesarean delivery for failure to progress, and she desired a repeat cesarean delivery. Fetal monitoring revealed a heart rate of 140 beats per minute with moderate variability and uterine contractions every 3 to 5 minutes associated with moderate variable decelerations. A decision was made to proceed with the surgery. Blood samples were drawn for laboratory analysis, monitoring was discontinued, and the patient was taken to the operating room. An epidural anesthetic was placed and the cesarean delivery proceeded.

On uterine incision, there was no evidence of abruption or uterine rupture, but thick meconium-stained amniotic fluid was observed. A depressed infant was delivered, the umbilical cord clamped, and the infant handed to the pediatric team. Cord samples were obtained and values from the umbilical artery were as follows: pH, 6.80; Pco₂, 120 mm Hg; Po₂, 6 mm Hg; and base deficit extracellular fluid (BD_ECF), 13.8 mmol/L. Values from the umbilical vein were: pH, 7.32; Pco₂, 38 mm Hg; Po₂, 22 mm Hg; and BD_ECF, 5.8 mmol/L. The infant’s Apgar scores were 1, 2, and 7 at 1, 5, and 10 minutes, respectively, and the infant demonstrated encephalopathy, requiring brain cooling.

What happened?

Read how to use cord gas values in practice

Using cord gas values in practice

Before analyzing the circumstances in Case 1,it is important to consider several key questions, including:

• What are the normal levels of cord pH, O₂, CO₂, and base deficit (BD)?
• How does cord gas indicate what happened during labor?
• What are the preventable errors in cord gas sampling or interpretation?

For a review of fetal cord gas physiology, see “Physiology of fetal cord gases: The basics”.

Normal values: The “20, 30, 40, 50 rule”

Among the values reported for umbilical blood gas, the pH, Pco₂, and Po₂ are measured, whereas BD is calculated. The normal values for umbilical pH and blood gases are often included with laboratory results, although typically with a broad, overlapping range of values that may make it difficult to determine which is umbilical artery or vein (TABLE 1).^6,7

I recommend using the “20, 30, 40, 50 rule” as a simple tool for remembering normal umbilical artery and vein Po₂ and Pco₂ values (TABLE 2):

• Po₂ values are lower than Pco₂ values; thus, the 20 and 30 represent Po₂ values
• as fetal umbilical artery Po₂ is lower than umbilical vein Po₂, 20 mm Hg represents the umbilical artery and 30 mm Hg represents the vein
• Pco₂ values are higher in the umbilical artery than in the vein; thus, 50 mm Hg represents the umbilical artery and 40 mm Hg represents the umbilical vein.

Umbilical cord BD values change in relation to labor and FHR decelerations.⁸ Prior to labor, the normal fetus has a slight degree of acidosis (BD, 2 mmol/L). During the latent phase of labor, fetal BD typically does not change. With the increased frequency of contractions, BD may increase 1 mmol/L for every 3 to 6 hours during the active phase and up to 1 mmol/L per hour during the second stage, depending on FHR responses. Thus, following vaginal delivery the average umbilical artery BD is approximately 5 mmol/L and the umbilical vein BD is approximately 4 mmol/L. As lactate crosses the placenta slowly, BD values are typically only 1 mmol/L less in the umbilical vein than in the artery, unless there has been an obstruction to placental flow (see Case 1).

For pH, the umbilical artery value is always lower than that of the vein, a result of both the higher umbilical artery Pco₂ as well as the slightly higher levels of lactic acid before placental clearance. Fetal pH levels typically decrease during labor associated with the increased BD described above. However, short-term effects of increased CO₂ (respiratory acidosis) or CO₂ clearance may cause fluctuations in pH that do not correlate with the degree of metabolic acidosis.

Possible causes of abnormal cord gas values

Because of the nearly fully saturated maternal hemoglobin under normal conditions, fetal arterial and venous Po₂ levels cannot be increased significantly above normal values. However, reduced fetal Po₂ and increased fetal Pco₂ may occur with poor gas exchange between the maternal and fetal compartments (eg, placental abruption) or maternal respiratory compromise.

In contrast, reduced fetal Pco₂ may occur under conditions of maternal hyperventilation and lower maternal Pco₂ values. Decreased pH levels may be due to respiratory or metabolic acidosis, the former of which is generally benign. Elevated BD typically is a result of fetal metabolic acidosis, and values approaching 12 mmol/L should be avoided, if possible, as this level may be associated with newborn neurologic injury.⁹

Effect of maternal oxygen administration on fetal oxygenation

Although maternal oxygen administration is commonly used during labor and delivery, controversy remains as to the benefit of oxygen supplementation.¹⁰ In a normal mother with oxygen saturation above 95%, the administration of oxygen will increase maternal arterial Po₂ levels and thus dissolved oxygen. Because maternal hemoglobin is normally almost fully saturated at room air Po₂ levels, there is little change in the bound oxygen and thus little change in the maternal arterial O₂ content or maternal uterine venous Po₂ levels. As fetal umbilical vein Po₂ levels equilibrate to maternal uterine vein Po₂ levels, there is minimal change in fetal oxygenation.

However, maternal oxygen supplementation may have marked benefit in cases in which maternal arterial Po₂ is low (respiratory compromise). In this case, the steep fetal oxygen saturation curve may produce a large increase in fetal umbilical vein oxygen content. Thus, strongly consider oxygen supplementation for mothers with impaired cardiorespiratory function, and recognize that maternal oxygen supplementation for normal mothers may result in nominal benefit for compromised fetuses.

How did the Case 1 circumstances lead to newborn acidosis?

Most noticeable in this case is the large difference in BD between the umbilical artery and vein and the high Pco₂in the artery. Under conditions without interruption of fetal placental flow, either the umbilical artery and/or vein will provide a similar assessment of fetal or newborn metabolic acidosis (that is, BD).

Whereas BD normally is only about 1 mmol/L greater in the umbilical artery versus in the vein, occasionally the arterial value is markedly greater than the vein value. This can occur when there is a cessation of blood flow through the placenta, as a result of complete umbilical cord obstruction, or when there is a uterine abruption. In these situations, the umbilical vein (which has not had blood flow) represents the fetal status prior to the occlusion event. In contrast, despite bradycardia, fetal heart pulsations mix blood within the umbilical artery and therefore the artery generally represents the fetal status at the time of birth.

In response to complete cord occlusion, fetal BD increases by approximately 1 mmol/L every 2 minutes. Consequently, an 8 mmol/L difference in BD between the umbilical artery and vein is consistent with a 16-minute period of umbilical occlusion or placental abruption. Also in response to complete umbilical cord occlusion, Pco₂ values rise by approximately 7 mm Hg per minute of the occlusion, although this may not be linear at higher levels. Thus, the BD difference suggests there was likely a complete cord occlusion for the 16 minutes prior to birth.

The umbilical vein BD is also elevated for early labor. This value suggests that repetitive, intermittent cord occlusions (evident on the initial fetal monitor tracing) likely resulted in this moderate acidosis prior to the complete cord occlusion in the final 16 minutes.

Thus, BD and Pco₂ levels can be used to time the onset of umbilical cord occlusion or abruption. Since pH is an inverse logarithmic function, it cannot be used to time the onset or duration of cord occlusion. Remember that BD values should be adjusted for extracellular fluid under conditions of markedly elevated Pco₂.

Read more cases plus procedures, equipment for cord sampling

Illustration: Kimberly Martens for OBG Management

CASE 2: An infant with unusual umbilical artery values

An infant born via vacuum delivery for a prolonged second stage of labor had 1- and 5-minute Apgar scores of 8 and 9, respectively. Cord gas values were obtained, and analysis revealed that for the umbilical artery, the pH was 7.29; Pco₂, 20 mm Hg; and Po₂, 60 mm Hg. For the umbilical vein, the pH was 7.32; Pco₂, 38 mm Hg; and Po₂, 22 mm Hg.

The resident asked, “How is the Po₂ higher in the artery than in the vein?”

The curious Case 2 values suggest an air bubble

Although it is possible that the aberrant values in Case 2 could have resulted from switching the artery and vein samples, the pH is lower in the artery, and both the artery Po₂ and Pco₂ levels do not appear physiologic. The likely explanation for these values is that an air bubble was contained in the syringe. Since normal room air (21% O₂) has a Po₂ of 159 mm Hg and a Pco₂ of less than 1 mm Hg, exposure of cord blood gases to air bubbles will significantly increase the Po₂ and markedly reduce the Pco₂ values of the sample. Take care to avoid air bubbles in the syringes used to obtain samples for analysis.

Related article:
Is neonatal injury more likely outside of a 30-minute decision-to-incision time interval for cesarean delivery?

CASE 3: A vigorous baby with significant acidosis

A baby with 1- and 5-minute Apgar scores of 9 and 9 was delivered by cesarean and remained vigorous. Umbilical cord analysis revealed an umbilical artery pH level of 7.15, with normal Po₂ and Pco₂ values. What could be the explanation?

Was there a collection error in Case 3?

On occasion, a falsely low pH level and, thus, a falsely elevated BD may result from excessive heparin in the collection syringe. Heparin is acidotic and should be used only to coat the syringe. Although syringes in current use are often pre-heparinized, if one is drawing up heparin into the syringe, it should be coated and then fully expelled.

Umbilical cord sampling: Procedures and equipment

Many issues remain regarding the optimal storage of cord samples. Ideally, a doubly clamped section of the cord promptly should be sampled into glass syringes that can be placed on ice and rapidly measured for cord values.

Stability of umbilical cord samples within the cord is within 20 to 30 minutes. Delayed sampling of clamped cord sections generally has minimal effect on pH and Pco₂ values.¹¹ The BD does not change to a clinically significant degree over 15 to 30 minutes despite the cord specimen remaining at room temperature. However, one report demonstrated an increase in lactate and BD by 20 minutes under these conditions; this likely was a result of metabolism from endothelial or blood cells.¹² I therefore recommend that clamped cord be sampled as soon as is feasible and ideally not beyond 20 to 30 minutes.

Plastic syringes can introduce interference. Several studies have demonstrated that collection of samples in plastic may result in an increase in Po₂ values, likely due to the high room air Po₂ diffusing through the plastic to the blood sample.

Use glass, and “ice” the sample if necessary. Although it has been suggested that placing samples on ice minimizes metabolism, the cooled plastic may in fact be more susceptible to oxygen diffusion. Thus, unless samples will be analyzed promptly, it is best to use glass syringes on ice.^13,14

Related article:
Protecting the newborn brain—the final frontier in obstetric and neonatal care

What if the umbilical cord is torn?

Sometimes the umbilical cord is torn and discarded or cannot be accessed for other reasons. A sample can still be obtained, however, by aspirating the placental surface artery and vein vessels. Although there is some potential variance in pH, Po₂, and Pco₂ levels, the BD values of placental vessels have a high correlation with those of umbilical vessels and therefore can be used when the cord is not available.¹⁵

How do you obtain cord analysis when delaying cord clamping?

The American College of Obstetricians and Gynecologists (ACOG) now advises delayed cord clamping in term and preterm deliveries, which raises the question of how you obtain a blood sample in this setting. Importantly, ACOG recommends delayed cord clamping only in vigorous infants,¹⁶ whereas potentially compromised infants should be transferred rapidly for newborn care. Although several studies have demonstrated some variation in cord gas values with delayed cord clamping,^17–21 clamping after pulsation has ceased or after the recommended 30 to 60 seconds following birth results in minimal change in BD values. Thus, do not hesitate to perform delayed cord clamping in vigorous infants.

Share your thoughts! Send your Letter to the Editor to [email protected]. Please include your name and the city and state in which you practice.

Umbilical cord blood (cord) gas values can aid both in understanding the cause of an infant’s acidosis and in providing reassurance that acute acidosis or asphyxia is not responsible for a compromised infant with a low Apgar score. Together with other clinical measurements (including fetal heart rate [FHR] tracings, Apgar scores, newborn nucleated red cell counts, and neonatal imaging), cord gas analysis can be remarkably helpful in determining the cause for a depressed newborn. It can help us determine, for example, if infant compromise was a result of an asphyxial event, and we often can differentiate whether the event was acute, prolonged, or occurred prior to presentation in labor. We further can use cord gas values to assess whether a decision for operative intervention for nonreassuring fetal well-being was appropriate (see “Brain injury at birth: Cord gas values presented as evidence at trial”). In addition, cord gas analysis can complement methods for determining fetal acidosis changes during labor, enabling improved assessment of FHR tracings.¹⁻³

I recommend checking umbilical cord blood gas values on all operative vaginal deliveries, cesarean deliveries for fetal concern, abnormal FHR patterns, clinical chorioamnionitis, multifetal gestations, premature deliveries, and all infants with low Apgar scores at 1 or 5 minutes. If you think you may need a cord gas analysis, go ahead and obtain it. Cord gas analysis often will aid in justifying your management or provide insight into the infant’s status.

Controversy remains as to the benefit of universal cord gas analysis. Assuming a variable cost of $15 for 2 (artery and vein) blood gas samples per neonate,⁴ the annual cost in the United States would be approximately $60 million. This would likely be cost effective as a result of medicolegal and educational benefits as well as potential improvements in perinatal outcome⁵ and reductions in special care nursery admissions.⁴

CASE 1: A newborn with unexpected acidosis

A 29-year-old woman (G2P1) at 38 weeks’ gestation was admitted to the hospital following an office visit during which oligohydramnios (amniotic fluid index, 3.5 cm) was found. The patient had a history of a prior cesarean delivery for failure to progress, and she desired a repeat cesarean delivery. Fetal monitoring revealed a heart rate of 140 beats per minute with moderate variability and uterine contractions every 3 to 5 minutes associated with moderate variable decelerations. A decision was made to proceed with the surgery. Blood samples were drawn for laboratory analysis, monitoring was discontinued, and the patient was taken to the operating room. An epidural anesthetic was placed and the cesarean delivery proceeded.

On uterine incision, there was no evidence of abruption or uterine rupture, but thick meconium-stained amniotic fluid was observed. A depressed infant was delivered, the umbilical cord clamped, and the infant handed to the pediatric team. Cord samples were obtained and values from the umbilical artery were as follows: pH, 6.80; Pco₂, 120 mm Hg; Po₂, 6 mm Hg; and base deficit extracellular fluid (BD_ECF), 13.8 mmol/L. Values from the umbilical vein were: pH, 7.32; Pco₂, 38 mm Hg; Po₂, 22 mm Hg; and BD_ECF, 5.8 mmol/L. The infant’s Apgar scores were 1, 2, and 7 at 1, 5, and 10 minutes, respectively, and the infant demonstrated encephalopathy, requiring brain cooling.

What happened?

Read how to use cord gas values in practice

Using cord gas values in practice

Before analyzing the circumstances in Case 1,it is important to consider several key questions, including:

• What are the normal levels of cord pH, O₂, CO₂, and base deficit (BD)?
• How does cord gas indicate what happened during labor?
• What are the preventable errors in cord gas sampling or interpretation?

For a review of fetal cord gas physiology, see “Physiology of fetal cord gases: The basics”.

Normal values: The “20, 30, 40, 50 rule”

Among the values reported for umbilical blood gas, the pH, Pco₂, and Po₂ are measured, whereas BD is calculated. The normal values for umbilical pH and blood gases are often included with laboratory results, although typically with a broad, overlapping range of values that may make it difficult to determine which is umbilical artery or vein (TABLE 1).^6,7

I recommend using the “20, 30, 40, 50 rule” as a simple tool for remembering normal umbilical artery and vein Po₂ and Pco₂ values (TABLE 2):

• Po₂ values are lower than Pco₂ values; thus, the 20 and 30 represent Po₂ values
• as fetal umbilical artery Po₂ is lower than umbilical vein Po₂, 20 mm Hg represents the umbilical artery and 30 mm Hg represents the vein
• Pco₂ values are higher in the umbilical artery than in the vein; thus, 50 mm Hg represents the umbilical artery and 40 mm Hg represents the umbilical vein.

Umbilical cord BD values change in relation to labor and FHR decelerations.⁸ Prior to labor, the normal fetus has a slight degree of acidosis (BD, 2 mmol/L). During the latent phase of labor, fetal BD typically does not change. With the increased frequency of contractions, BD may increase 1 mmol/L for every 3 to 6 hours during the active phase and up to 1 mmol/L per hour during the second stage, depending on FHR responses. Thus, following vaginal delivery the average umbilical artery BD is approximately 5 mmol/L and the umbilical vein BD is approximately 4 mmol/L. As lactate crosses the placenta slowly, BD values are typically only 1 mmol/L less in the umbilical vein than in the artery, unless there has been an obstruction to placental flow (see Case 1).

For pH, the umbilical artery value is always lower than that of the vein, a result of both the higher umbilical artery Pco₂ as well as the slightly higher levels of lactic acid before placental clearance. Fetal pH levels typically decrease during labor associated with the increased BD described above. However, short-term effects of increased CO₂ (respiratory acidosis) or CO₂ clearance may cause fluctuations in pH that do not correlate with the degree of metabolic acidosis.

Possible causes of abnormal cord gas values

Because of the nearly fully saturated maternal hemoglobin under normal conditions, fetal arterial and venous Po₂ levels cannot be increased significantly above normal values. However, reduced fetal Po₂ and increased fetal Pco₂ may occur with poor gas exchange between the maternal and fetal compartments (eg, placental abruption) or maternal respiratory compromise.

In contrast, reduced fetal Pco₂ may occur under conditions of maternal hyperventilation and lower maternal Pco₂ values. Decreased pH levels may be due to respiratory or metabolic acidosis, the former of which is generally benign. Elevated BD typically is a result of fetal metabolic acidosis, and values approaching 12 mmol/L should be avoided, if possible, as this level may be associated with newborn neurologic injury.⁹

Effect of maternal oxygen administration on fetal oxygenation

Although maternal oxygen administration is commonly used during labor and delivery, controversy remains as to the benefit of oxygen supplementation.¹⁰ In a normal mother with oxygen saturation above 95%, the administration of oxygen will increase maternal arterial Po₂ levels and thus dissolved oxygen. Because maternal hemoglobin is normally almost fully saturated at room air Po₂ levels, there is little change in the bound oxygen and thus little change in the maternal arterial O₂ content or maternal uterine venous Po₂ levels. As fetal umbilical vein Po₂ levels equilibrate to maternal uterine vein Po₂ levels, there is minimal change in fetal oxygenation.

However, maternal oxygen supplementation may have marked benefit in cases in which maternal arterial Po₂ is low (respiratory compromise). In this case, the steep fetal oxygen saturation curve may produce a large increase in fetal umbilical vein oxygen content. Thus, strongly consider oxygen supplementation for mothers with impaired cardiorespiratory function, and recognize that maternal oxygen supplementation for normal mothers may result in nominal benefit for compromised fetuses.

How did the Case 1 circumstances lead to newborn acidosis?

Most noticeable in this case is the large difference in BD between the umbilical artery and vein and the high Pco₂in the artery. Under conditions without interruption of fetal placental flow, either the umbilical artery and/or vein will provide a similar assessment of fetal or newborn metabolic acidosis (that is, BD).

Whereas BD normally is only about 1 mmol/L greater in the umbilical artery versus in the vein, occasionally the arterial value is markedly greater than the vein value. This can occur when there is a cessation of blood flow through the placenta, as a result of complete umbilical cord obstruction, or when there is a uterine abruption. In these situations, the umbilical vein (which has not had blood flow) represents the fetal status prior to the occlusion event. In contrast, despite bradycardia, fetal heart pulsations mix blood within the umbilical artery and therefore the artery generally represents the fetal status at the time of birth.

In response to complete cord occlusion, fetal BD increases by approximately 1 mmol/L every 2 minutes. Consequently, an 8 mmol/L difference in BD between the umbilical artery and vein is consistent with a 16-minute period of umbilical occlusion or placental abruption. Also in response to complete umbilical cord occlusion, Pco₂ values rise by approximately 7 mm Hg per minute of the occlusion, although this may not be linear at higher levels. Thus, the BD difference suggests there was likely a complete cord occlusion for the 16 minutes prior to birth.

The umbilical vein BD is also elevated for early labor. This value suggests that repetitive, intermittent cord occlusions (evident on the initial fetal monitor tracing) likely resulted in this moderate acidosis prior to the complete cord occlusion in the final 16 minutes.

Thus, BD and Pco₂ levels can be used to time the onset of umbilical cord occlusion or abruption. Since pH is an inverse logarithmic function, it cannot be used to time the onset or duration of cord occlusion. Remember that BD values should be adjusted for extracellular fluid under conditions of markedly elevated Pco₂.

Read more cases plus procedures, equipment for cord sampling

Illustration: Kimberly Martens for OBG Management

CASE 2: An infant with unusual umbilical artery values

An infant born via vacuum delivery for a prolonged second stage of labor had 1- and 5-minute Apgar scores of 8 and 9, respectively. Cord gas values were obtained, and analysis revealed that for the umbilical artery, the pH was 7.29; Pco₂, 20 mm Hg; and Po₂, 60 mm Hg. For the umbilical vein, the pH was 7.32; Pco₂, 38 mm Hg; and Po₂, 22 mm Hg.

The resident asked, “How is the Po₂ higher in the artery than in the vein?”

The curious Case 2 values suggest an air bubble

Although it is possible that the aberrant values in Case 2 could have resulted from switching the artery and vein samples, the pH is lower in the artery, and both the artery Po₂ and Pco₂ levels do not appear physiologic. The likely explanation for these values is that an air bubble was contained in the syringe. Since normal room air (21% O₂) has a Po₂ of 159 mm Hg and a Pco₂ of less than 1 mm Hg, exposure of cord blood gases to air bubbles will significantly increase the Po₂ and markedly reduce the Pco₂ values of the sample. Take care to avoid air bubbles in the syringes used to obtain samples for analysis.

Related article:
Is neonatal injury more likely outside of a 30-minute decision-to-incision time interval for cesarean delivery?

CASE 3: A vigorous baby with significant acidosis

A baby with 1- and 5-minute Apgar scores of 9 and 9 was delivered by cesarean and remained vigorous. Umbilical cord analysis revealed an umbilical artery pH level of 7.15, with normal Po₂ and Pco₂ values. What could be the explanation?

Was there a collection error in Case 3?

On occasion, a falsely low pH level and, thus, a falsely elevated BD may result from excessive heparin in the collection syringe. Heparin is acidotic and should be used only to coat the syringe. Although syringes in current use are often pre-heparinized, if one is drawing up heparin into the syringe, it should be coated and then fully expelled.

Umbilical cord sampling: Procedures and equipment

Many issues remain regarding the optimal storage of cord samples. Ideally, a doubly clamped section of the cord promptly should be sampled into glass syringes that can be placed on ice and rapidly measured for cord values.

Stability of umbilical cord samples within the cord is within 20 to 30 minutes. Delayed sampling of clamped cord sections generally has minimal effect on pH and Pco₂ values.¹¹ The BD does not change to a clinically significant degree over 15 to 30 minutes despite the cord specimen remaining at room temperature. However, one report demonstrated an increase in lactate and BD by 20 minutes under these conditions; this likely was a result of metabolism from endothelial or blood cells.¹² I therefore recommend that clamped cord be sampled as soon as is feasible and ideally not beyond 20 to 30 minutes.

Plastic syringes can introduce interference. Several studies have demonstrated that collection of samples in plastic may result in an increase in Po₂ values, likely due to the high room air Po₂ diffusing through the plastic to the blood sample.

Use glass, and “ice” the sample if necessary. Although it has been suggested that placing samples on ice minimizes metabolism, the cooled plastic may in fact be more susceptible to oxygen diffusion. Thus, unless samples will be analyzed promptly, it is best to use glass syringes on ice.^13,14

Related article:
Protecting the newborn brain—the final frontier in obstetric and neonatal care

What if the umbilical cord is torn?

Sometimes the umbilical cord is torn and discarded or cannot be accessed for other reasons. A sample can still be obtained, however, by aspirating the placental surface artery and vein vessels. Although there is some potential variance in pH, Po₂, and Pco₂ levels, the BD values of placental vessels have a high correlation with those of umbilical vessels and therefore can be used when the cord is not available.¹⁵

How do you obtain cord analysis when delaying cord clamping?

The American College of Obstetricians and Gynecologists (ACOG) now advises delayed cord clamping in term and preterm deliveries, which raises the question of how you obtain a blood sample in this setting. Importantly, ACOG recommends delayed cord clamping only in vigorous infants,¹⁶ whereas potentially compromised infants should be transferred rapidly for newborn care. Although several studies have demonstrated some variation in cord gas values with delayed cord clamping,^17–21 clamping after pulsation has ceased or after the recommended 30 to 60 seconds following birth results in minimal change in BD values. Thus, do not hesitate to perform delayed cord clamping in vigorous infants.

Share your thoughts! Send your Letter to the Editor to [email protected]. Please include your name and the city and state in which you practice.

She wanted to labor on hands and knees

During prenatal visits, a woman, pregnant with her fourth child, discussed undergoing labor and delivery in any position other than on her back; the ObGyn agreed. When she arrived at the hospital in labor, the patient told the nurse that she preferred to labor on her hands and knees. The nurse disagreed because of the fetal heart-rate monitor.

When the patient began hard labor, she turned herself over onto her hands and knees and again informed the nurse that she could not labor on her back. The nurse flipped the patient onto her back by taking her wrists and pulling the patient’s hands out from under her. The nurse then delayed delivery until the ObGyn arrived by putting pressure on the baby’s head. During delivery, a second nurse forcibly pressed the patient’s left knee back toward her chest, leaving her legs in an asymmetric position.

Two months later, the patient reported chronic severe pelvic pain and was found to have pudendal neuralgia. She underwent nerve blocks and takes medication for chronic pain.

PATIENT’S CLAIM:

The ObGyn did not assume responsibility when he arrived for the delivery. The nurses did not follow the standard of care. The patient’s injury was the result of tension and compression due to malpositioning of the patient’s legs during delivery.

DEFENDANTS’ DEFENSE:

There was no breach in the standard of care. The patient’s injury, if any, had not been caused by the delivery.

VERDICT:

A $16 million Alabama verdict was returned.

Related article:
10 tips for overcoming common challenges of intrapartum fetal monitoring

Late-term abortion: $1.4M award

Although genetic testing was scheduled for a 37-year-old woman’s 15-week prenatal visit, the ObGyn’s staff failed to draw blood. At 19 weeks’ gestation (April 24), blood was drawn. The ObGyn signed off on test results that showed a high risk for fetal anomaly on May 2, but the patient was not informed until May 22. The ObGyn scheduled amniocentesis for June 3. On May 30, the hospital, based in Illinois, cancelled the test, telling the ObGyn that it was because the patient was over 24 weeks’ pregnant and there was no labor and delivery unit to respond if complications arose. Instead of notifying the patient, the ObGyn arranged for amniocentesis to be performed elsewhere on June 3. The ObGyn saw the amniocentesis results on June 13, but did not tell the patient until July 3, when he advised her to terminate the pregnancy because the baby had severe cardiac defects and Down syndrome; he felt the child would not survive or have very poor quality of life. The ObGyn arranged for the patient to undergo a third-trimester abortion in Kansas and paid all expenses. On July 14, the patient began the 5-day abortion process at 30+ weeks’ gestation.

PATIENT’S CLAIM:

She was never offered additional genetic testing or expedited amniocentesis. She was not told that abortion is illegal in Illinois after 23 6/7 weeks’ gestation. The ObGyn had a motive for paying for her abortion. He never counseled her about options to keep the child. She endured extreme pain and emotional trauma during the abortion and was later found to have posttraumatic stress disorder, multidepressive disorder, and anxiety as a result of the experience. She countered the ObGyn’s contact information claim by saying that her phone number had not changed.

PHYSICIAN’S DEFENSE:

The ObGyn admitted negligence in failing to timely communicate test results but contended that the patient was more than 50% responsible for any delay by failing to update her contact information when she moved. The ObGyn denied causation of any injuries or damage.

VERDICT:

A $1,439,250 Illinois verdict was returned.

Related article:
4 Supreme Court decisions important to ObGyns from the 2015−2016 term

Did delay in delivery cause infant's death?

A woman presented to the hospital in labor. During delivery, the patient’s ObGyn encountered shoulder dystocia. The infant died shortly after birth.

PARENTS’ CLAIM:

The ObGyn and hospital nurses were negligent. The nurses failed to monitor labor and properly communicate with the ObGyn. The ObGyn failed to appreciate the baby’s large size and order a cesarean delivery. The infant’s death was due to a hypoxic event during delivery.

DEFENDANTS’ DEFENSE:

The baby gained an unexpected amount of weight between the last prenatal visit and labor. There was no reason to expect a complication to vaginal delivery. The nurses denied negligence. The child’s sudden death was caused by a genetic cardiac condition.

VERDICT:

A Tennessee defense verdict was returned.

Related article:
Shoulder dystocia: Taking the fear out of management

These cases were selected by the editors of OBG Management from Medical Malpractice Verdicts, Settlements & Experts, with permission of the editor, Lewis Laska (www.verdictslaska.com). The information available to the editors about the cases presented here is sometimes incomplete. Moreover, the cases may or may not have merit. Nevertheless, these cases represent the types of clinical situations that typically result in litigation and are meant to illustrate nationwide variation in jury verdicts and awards.

Share your thoughts! Send your Letter to the Editor to [email protected]. Please include your name and the city and state in which you practice.

She wanted to labor on hands and knees

During prenatal visits, a woman, pregnant with her fourth child, discussed undergoing labor and delivery in any position other than on her back; the ObGyn agreed. When she arrived at the hospital in labor, the patient told the nurse that she preferred to labor on her hands and knees. The nurse disagreed because of the fetal heart-rate monitor.

When the patient began hard labor, she turned herself over onto her hands and knees and again informed the nurse that she could not labor on her back. The nurse flipped the patient onto her back by taking her wrists and pulling the patient’s hands out from under her. The nurse then delayed delivery until the ObGyn arrived by putting pressure on the baby’s head. During delivery, a second nurse forcibly pressed the patient’s left knee back toward her chest, leaving her legs in an asymmetric position.

Two months later, the patient reported chronic severe pelvic pain and was found to have pudendal neuralgia. She underwent nerve blocks and takes medication for chronic pain.

PATIENT’S CLAIM:

The ObGyn did not assume responsibility when he arrived for the delivery. The nurses did not follow the standard of care. The patient’s injury was the result of tension and compression due to malpositioning of the patient’s legs during delivery.

DEFENDANTS’ DEFENSE:

There was no breach in the standard of care. The patient’s injury, if any, had not been caused by the delivery.

VERDICT:

A $16 million Alabama verdict was returned.

Related article:
10 tips for overcoming common challenges of intrapartum fetal monitoring

Late-term abortion: $1.4M award

Although genetic testing was scheduled for a 37-year-old woman’s 15-week prenatal visit, the ObGyn’s staff failed to draw blood. At 19 weeks’ gestation (April 24), blood was drawn. The ObGyn signed off on test results that showed a high risk for fetal anomaly on May 2, but the patient was not informed until May 22. The ObGyn scheduled amniocentesis for June 3. On May 30, the hospital, based in Illinois, cancelled the test, telling the ObGyn that it was because the patient was over 24 weeks’ pregnant and there was no labor and delivery unit to respond if complications arose. Instead of notifying the patient, the ObGyn arranged for amniocentesis to be performed elsewhere on June 3. The ObGyn saw the amniocentesis results on June 13, but did not tell the patient until July 3, when he advised her to terminate the pregnancy because the baby had severe cardiac defects and Down syndrome; he felt the child would not survive or have very poor quality of life. The ObGyn arranged for the patient to undergo a third-trimester abortion in Kansas and paid all expenses. On July 14, the patient began the 5-day abortion process at 30+ weeks’ gestation.

PATIENT’S CLAIM:

She was never offered additional genetic testing or expedited amniocentesis. She was not told that abortion is illegal in Illinois after 23 6/7 weeks’ gestation. The ObGyn had a motive for paying for her abortion. He never counseled her about options to keep the child. She endured extreme pain and emotional trauma during the abortion and was later found to have posttraumatic stress disorder, multidepressive disorder, and anxiety as a result of the experience. She countered the ObGyn’s contact information claim by saying that her phone number had not changed.

PHYSICIAN’S DEFENSE:

The ObGyn admitted negligence in failing to timely communicate test results but contended that the patient was more than 50% responsible for any delay by failing to update her contact information when she moved. The ObGyn denied causation of any injuries or damage.

VERDICT:

A $1,439,250 Illinois verdict was returned.

Related article:
4 Supreme Court decisions important to ObGyns from the 2015−2016 term

Did delay in delivery cause infant's death?

A woman presented to the hospital in labor. During delivery, the patient’s ObGyn encountered shoulder dystocia. The infant died shortly after birth.

PARENTS’ CLAIM:

The ObGyn and hospital nurses were negligent. The nurses failed to monitor labor and properly communicate with the ObGyn. The ObGyn failed to appreciate the baby’s large size and order a cesarean delivery. The infant’s death was due to a hypoxic event during delivery.

DEFENDANTS’ DEFENSE:

The baby gained an unexpected amount of weight between the last prenatal visit and labor. There was no reason to expect a complication to vaginal delivery. The nurses denied negligence. The child’s sudden death was caused by a genetic cardiac condition.

VERDICT:

A Tennessee defense verdict was returned.

Related article:
Shoulder dystocia: Taking the fear out of management

These cases were selected by the editors of OBG Management from Medical Malpractice Verdicts, Settlements & Experts, with permission of the editor, Lewis Laska (www.verdictslaska.com). The information available to the editors about the cases presented here is sometimes incomplete. Moreover, the cases may or may not have merit. Nevertheless, these cases represent the types of clinical situations that typically result in litigation and are meant to illustrate nationwide variation in jury verdicts and awards.

Share your thoughts! Send your Letter to the Editor to [email protected]. Please include your name and the city and state in which you practice.

She wanted to labor on hands and knees

During prenatal visits, a woman, pregnant with her fourth child, discussed undergoing labor and delivery in any position other than on her back; the ObGyn agreed. When she arrived at the hospital in labor, the patient told the nurse that she preferred to labor on her hands and knees. The nurse disagreed because of the fetal heart-rate monitor.

When the patient began hard labor, she turned herself over onto her hands and knees and again informed the nurse that she could not labor on her back. The nurse flipped the patient onto her back by taking her wrists and pulling the patient’s hands out from under her. The nurse then delayed delivery until the ObGyn arrived by putting pressure on the baby’s head. During delivery, a second nurse forcibly pressed the patient’s left knee back toward her chest, leaving her legs in an asymmetric position.

Two months later, the patient reported chronic severe pelvic pain and was found to have pudendal neuralgia. She underwent nerve blocks and takes medication for chronic pain.

PATIENT’S CLAIM:

The ObGyn did not assume responsibility when he arrived for the delivery. The nurses did not follow the standard of care. The patient’s injury was the result of tension and compression due to malpositioning of the patient’s legs during delivery.

DEFENDANTS’ DEFENSE:

There was no breach in the standard of care. The patient’s injury, if any, had not been caused by the delivery.

VERDICT:

A $16 million Alabama verdict was returned.

Related article:
10 tips for overcoming common challenges of intrapartum fetal monitoring

Late-term abortion: $1.4M award

Although genetic testing was scheduled for a 37-year-old woman’s 15-week prenatal visit, the ObGyn’s staff failed to draw blood. At 19 weeks’ gestation (April 24), blood was drawn. The ObGyn signed off on test results that showed a high risk for fetal anomaly on May 2, but the patient was not informed until May 22. The ObGyn scheduled amniocentesis for June 3. On May 30, the hospital, based in Illinois, cancelled the test, telling the ObGyn that it was because the patient was over 24 weeks’ pregnant and there was no labor and delivery unit to respond if complications arose. Instead of notifying the patient, the ObGyn arranged for amniocentesis to be performed elsewhere on June 3. The ObGyn saw the amniocentesis results on June 13, but did not tell the patient until July 3, when he advised her to terminate the pregnancy because the baby had severe cardiac defects and Down syndrome; he felt the child would not survive or have very poor quality of life. The ObGyn arranged for the patient to undergo a third-trimester abortion in Kansas and paid all expenses. On July 14, the patient began the 5-day abortion process at 30+ weeks’ gestation.

PATIENT’S CLAIM:

She was never offered additional genetic testing or expedited amniocentesis. She was not told that abortion is illegal in Illinois after 23 6/7 weeks’ gestation. The ObGyn had a motive for paying for her abortion. He never counseled her about options to keep the child. She endured extreme pain and emotional trauma during the abortion and was later found to have posttraumatic stress disorder, multidepressive disorder, and anxiety as a result of the experience. She countered the ObGyn’s contact information claim by saying that her phone number had not changed.

PHYSICIAN’S DEFENSE:

The ObGyn admitted negligence in failing to timely communicate test results but contended that the patient was more than 50% responsible for any delay by failing to update her contact information when she moved. The ObGyn denied causation of any injuries or damage.

VERDICT:

A $1,439,250 Illinois verdict was returned.

Related article:
4 Supreme Court decisions important to ObGyns from the 2015−2016 term

Did delay in delivery cause infant's death?

A woman presented to the hospital in labor. During delivery, the patient’s ObGyn encountered shoulder dystocia. The infant died shortly after birth.

PARENTS’ CLAIM:

The ObGyn and hospital nurses were negligent. The nurses failed to monitor labor and properly communicate with the ObGyn. The ObGyn failed to appreciate the baby’s large size and order a cesarean delivery. The infant’s death was due to a hypoxic event during delivery.

DEFENDANTS’ DEFENSE:

The baby gained an unexpected amount of weight between the last prenatal visit and labor. There was no reason to expect a complication to vaginal delivery. The nurses denied negligence. The child’s sudden death was caused by a genetic cardiac condition.

VERDICT:

A Tennessee defense verdict was returned.

Related article:
Shoulder dystocia: Taking the fear out of management

These cases were selected by the editors of OBG Management from Medical Malpractice Verdicts, Settlements & Experts, with permission of the editor, Lewis Laska (www.verdictslaska.com). The information available to the editors about the cases presented here is sometimes incomplete. Moreover, the cases may or may not have merit. Nevertheless, these cases represent the types of clinical situations that typically result in litigation and are meant to illustrate nationwide variation in jury verdicts and awards.

Share your thoughts! Send your Letter to the Editor to [email protected]. Please include your name and the city and state in which you practice.