Sarah S. Osmundson

Elective induction compared with expectant management in nulliparous women with a favorable cervix.

OBJECTIVE: To compare outcomes of labor between nulliparous women with a favorable cervix who underwent either elective labor induction or expectant management beyond 39 weeks of gestation. METHODS: A retrospective cohort study was conducted of nulliparous women with a singleton gestation who had a favorable cervix (modified Bishop score of at least 5) and delivered between 2006 and 2008. Two hundred ninety-four nulliparous women who underwent elective induction of labor between 39 and 40 5/7 weeks of gestation were compared with 294 nulliparous women who were expectantly managed beyond 39 weeks of gestation. RESULTS: The primary outcome, cesarean delivery, was similar between the two groups (20.8% compared with 20.1%, respectively, P=.84), a result that did not change in multivariable analysis. There were also no significant differences in other maternal (eg, chorioamnionitis, meconium, operative vaginal delivery, third- and fourth-degree lacerations, postpartum hemorrhage), or neonatal (arterial cord pH less than 7.0, Apgar score less than 4 at 5 minutes, neonatal intensive care unit admission) outcomes. Women who underwent an elective labor induction did have longer duration in labor and delivery between admission and delivery (median 12.7 compared with 9.0 hours, P<.001). CONCLUSION: For nulliparous women with a favorable cervix, elective labor induction has a similar chance of resulting in cesarean delivery as expectant management, although it appears to result in an increase in resource use. LEVEL OF EVIDENCE: II

Racial/Ethnic Differences in Gestational Diabetes Prevalence and Contribution of Common Risk Factors

BACKGROUND The White House, the American Heart Association, the Agency for Healthcare Research and Quality, and the National Heart, Lung and Blood Institute have all recently acknowledged the need to disaggregate Asian American subgroups to better understand this heterogeneous racial group. This study aims to assess racial/ethnic differences in relative contribution of risk factors of gestational diabetes mellitus (GDM) among Asian subgroups (Asian Indian, Chinese, Filipino, Japanese, Korean, and Vietnamese), Hispanics, non-Hispanic blacks, and non-Hispanic whites. METHODS Pregnant women in 2007-2012 were identified through California state birth certificate records and linked to the electronic health records in a large mixed-payer ambulatory care organisation in Northern California (n = 24 195). Relative risk and population attributable fraction (PAF) for specific racial/ethnic groups were calculated to assess the contributions of advanced maternal age, overweight/obesity (Centers for Disease Control and Prevention (CDC) standards and World Health Organization (WHO)/American Diabetes Association (ADA) body mass index cut-offs for Asians), family history of type 2 diabetes, and foreign-born status. RESULTS GDM was most prevalent among Asian Indians (19.3%). Relative risks were similar across all race/ethnic groups. Advanced maternal age had higher PAFs in non-Hispanic whites (22.5%) and Hispanics (22.7%). Meanwhile family history (Asian Indians 22.6%, Chinese 22.9%) and foreign-borne status (Chinese 40.2%, Filipinos 30.2%) had higher PAFs in Asian subgroups. Overweight/obesity was the most important GDM risk factor for non-Hispanic whites, Hispanics, Asian Indians, and Filipinos when the WHO/ADA cut-off points were applied. Advanced maternal age was the only risk factor studied that was modified by race/ethnicity, with non-Hispanic white and Hispanic women being more adversely affected than other racial/ethnic groups. CONCLUSIONS Overweight/obesity, advanced maternal age, family history of type 2 diabetes, and foreign-borne status are important risk factors for GDM. The relative contributions of these risk factors differ by race/ethnicity, mainly due to differences in population prevalence of these risk factors.

Body mass index and operative times at cesarean delivery.

OBJECTIVE: To examine the relationship between body mass index (BMI, kg/m2) and incision-to-delivery interval and total operative time at cesarean delivery. METHODS: Women with singleton gestations undergoing uncomplicated primary and repeat cesarean deliveries were identified from the Maternal-Fetal Medicine Units Network Cesarean Registry. Women were classified by BMI category at time of delivery (normal 18.5–24.9, overweight 25.0–29.9, obese 30.0–39.9, and morbidly obese 40 or greater). Incision-to-delivery interval and total operative times during cesarean delivery were compared among the three groups. Primary outcome was prolonged incision-to-delivery interval as defined by 90th percentile or greater of the study population or 18 minutes or longer. RESULTS: Of the 21,372 women included in the analysis, 9,928 were obese (46.5%) and 2,988 (14.0%) were morbidly obese. Longer operative times were found among women with overweight (median [interquartile range] incision-to-delivery: 9.0 [6.0] and total operative time: 45.0 [21.0] minutes), obese (10.0 [7.0]; 48.0 [22.0] minutes), and morbidly obese BMIs (12.0 [8.0]; 55.0 [26.0] minutes) compared with women with normal BMI at delivery (9.0 [5.0]; 43.0 [20.0] minutes) (P<.001). Morbidly obese women had a more frequent incision-to-delivery interval that was 18 minutes or longer (n=602 [20%] compared with 127 [6%] in normal BMI). After adjustments including number of prior cesarean deliveries, incision-to-delivery interval 18 minutes or longer was significantly related to obese (odds ratio [OR] 1.62, 95% confidence interval [CI] 1.31–2.03) and morbidly obese (OR 2.81, 95% CI 2.24–3.56) BMI at delivery. CONCLUSION: Increasing BMI is related to increased incision-to-delivery interval and total operative time at cesarean delivery with morbidly obese BMI exposing women to the highest risk of prolonged incision-to-delivery interval. LEVEL OF EVIDENCE: II

Postdischarge Opioid Use After Cesarean Delivery

OBJECTIVE To characterize postdischarge opioid use and examine factors associated with variation in opioid prescribing and consumption. METHODS We conducted a prospective observational cohort study by recruiting all women undergoing cesarean delivery during an 8-week period, excluding those with major postoperative morbidities or chronic opioid use. Starting on postoperative day 14, women were queried weekly regarding number of opioid pills used, amount remaining, and their pain experience until they had stopped opioid medication. Demographic and delivery information and in-hospital opioid use were recorded. The state Substance Monitoring Program was accessed to ascertain prescription-filling details. Morphine milligram equivalents were calculated to perform opioid use comparisons. Women in the highest quartile of opioid use (top opioid quartile use) were compared with those in the lowest three quartiles (average opioid use). RESULTS Of 251 eligible patients, 246 (98%) agreed to participate. Complete follow-up data were available for 179 (71% of eligible). Most women (83%) used opioids after discharge for a median of 8 days (interquartile range 6-13 days). Of women who filled their prescriptions (165 [92%]), 75% had unused tablets (median per person 75 morphine milligram equivalents, interquartile range 0-187, maximum 630) and the majority (63%) stored tablets in an unlocked location. This amounts to an equivalent of 2,540 unused 5-mg oxycodone tablets over our study period. Women who used all prescribed opioids (n=40 [22%]) were more likely to report that they received too few tablets than women who used some (n=109 [61%]) or none (n=30 [17%]) of the prescribed opioids (33% compared with 4% compared with 5%, P<.001). The top quartile was more likely to be smokers than average users and consumed more opioid morphine milligram equivalents per hour of inpatient stay than average opioid users (1.6, interquartile range 1.1-2.3 compared with 1.0, interquartile range 0.5-1.4, P<.001). CONCLUSION Most women-especially those with normal in-hospital opioid use-are prescribed opioids in excess of the amount needed.

Second-Trimester Placental Location and Postpartum Hemorrhage

The purpose of this study was to assess whether low placentation in the second trimester is an independent risk factor for postpartum hemorrhage.

Maternal proteinuria in twin compared with singleton pregnancies.

OBJECTIVE: To compare 24-hour urinary protein excretion in twin and singleton pregnancies not complicated by hypertension. METHODS: We prospectively evaluated mean 24-hour urinary protein excretion in twin and singleton pregnancies between 24 0/7 weeks and 36 0/7 weeks of gestation. Women with urinary tract infections, chronic hypertension, pregestational diabetes, and renal or autoimmune diseases were excluded. Collection adequacy was assessed by urinary creatinine excretion adjusted for maternal weight. RESULTS: Adequate samples were obtained from 50 twin and 49 singleton pregnancies at a mean gestational age of 30 weeks. At collection, the two groups were similar with regard to maternal age, gestational age, body mass index, and blood pressure. Mean urinary protein excretion was higher in twin compared with singleton pregnancies (269.3±124.1 mg compared with 204.3±92.5 mg, P=.004). Proteinuria (300 mg/day protein or greater) occurred in 38.0% (n=19) of twin and 8.2% (n=4) of singleton pregnancies (P<.001). After adjusting for confounding variables, the difference in mean total protein excretion remained significant (P=.004) and twins were more likely to have proteinuria compared with singleton pregnancies (adjusted odds ratio 9.1, 95% confidence interval 2.1–38.5). Nineteen participants developed a hypertensive disorder at a mean of 7.7 weeks after the urine collection (range 2.6–14.5 weeks). After excluding these women, proteinuria was present in 43% of twin and 7% of singleton pregnancies (P<.001). CONCLUSION: Mean 24-hour urinary protein excretion in twin pregnancies is greater than in singletons. These data suggest a reevaluation of the diagnostic criteria for preeclampsia in twin pregnancies. LEVEL OF EVIDENCE: II

Early Screening and Treatment of Women with Prediabetes: A Randomized Controlled Trial

OBJECTIVE To examine whether women with prediabetes benefit from early treatment for gestational diabetes mellitus (GDM). STUDY DESIGN Women with a glycosylated hemoglobin A1C (A1C) of 5.7 to 6.4% at <14 weeks were recruited. Participants were randomized to usual care or treatment for GDM with diet, blood glucose monitoring, and insulin as needed. The primary outcome was a 75-g oral glucose tolerance test at 26 to 28 weeks. Secondary outcomes included cesarean delivery, birthweight, weight gain, and A1C change. RESULTS Between May 2012 and June 2014, 95 women were enrolled and 83 had data for analysis; 42 were randomized to treatment and 41 to usual care. The groups were similar in baseline characteristics with 40% obese. There was no difference in the primary outcome (treatment 45.2% vs. control 56.1%; relative risk [RR] 0.80; 95% confidence interval [CI] 0.53-1.24) except that women in the treatment group had a significantly lower A1C over time than women in the control group (p = 0.04). Nonobese women (n = 50) treated for GDM experienced a 50% reduction in GDM compared with controls (29.6 vs. 60.9%; RR 0.49; 95% CI 0.25-0.95). CONCLUSION Early treatment for women with a first-trimester A1C of 5.7 to 6.4% did not significantly reduce the risk of GDM except in nonobese women.

Risk factors for classical hysterotomy by gestational age.

OBJECTIVE: To examine the likelihood of classical hysterotomy across preterm gestational ages and to identify factors that increase its occurrence. METHODS: This is a secondary analysis of a prospective observational cohort collected by the Maternal-Fetal Medicine Network of all women with singleton gestations who underwent a cesarean delivery with a known hysterotomy. Comparisons were made based on gestational age. Factors thought to influence hysterotomy type were studied, including maternal age, body mass index, parity, birth weight, small for gestational age (SGA) status, fetal presentation, labor preceding delivery, and emergent delivery. RESULTS: Approximately 36,000 women were eligible for analysis, of whom 34,454 (95.7%) underwent low transverse hysterotomy and 1,562 (4.3%) underwent classical hysterotomy. The median gestational age of women undergoing a classical hysterotomy was 32 weeks and the incidence peaked between 24 0/7 weeks and 25 6/7 weeks (53.2%), declining with each additional week of gestation thereafter (P for trend <.001). In multivariable regression, the likelihood of classical hysterotomy was increased with SGA (n=258; odds ratio [OR] 2.71; confidence interval [CI] 1.78–4.13), birth weight 1,000 g or less (n=467; OR 1.51; CI 1.03–2.24), and noncephalic presentation (n=783; OR 2.03; CI 1.52–2.72). The likelihood of classical hysterotomy was decreased between 23 0/7 and 27 6/7 weeks of gestation and after 32 weeks of gestation when labor preceded delivery, and increased between 28 0/7 and 31 6/7 weeks of gestation and after 32 weeks of gestation by multiparity and previous cesarean delivery. Emergent delivery did not predict classical hysterotomy. CONCLUSIONS: Fifty percent of women at 23–26 weeks of gestation who undergo cesarean delivery have a classical hysterotomy, and the risk declines steadily thereafter. This likelihood is increased by fetal factors, especially SGA and noncephalic presentation. LEVEL OF EVIDENCE: II

Does Infection During Pregnancy Outside of the Time of Delivery Increase the Risk of Cerebral Palsy

Objective We sought to evaluate whether maternal antepartum infection (excluding chorioamnionitis) is associated with cerebral palsy (CP). Study Design This is a secondary analysis from a multicenter trial in women at risk of preterm delivery who received antenatal magnesium sulfate versus placebo. We compared the risk of CP in the children of women who had evidence of antepartum infection over the course of pregnancy to those women who had no evidence of antepartum infection during pregnancy. Results Within a cohort of 2,251 women who met our inclusion criteria, 1,350 women had no history of infection in pregnancy and 801 women had a history of some type of antepartum infection during pregnancy. The incidence of CP was similar between the two groups (4.9 vs 5.0%; p = 0.917). After adjustment for maternal and obstetric confounders, we observed no significantly increased risk of CP among infants born to women with evidence of antepartum infection; (adjusted relative risk [aRR], 1.09 (0.72, 1.66); p = 0.68). Conclusion Compared with women with no evidence of antepartum infection during pregnancy, those women with infections excluding chorioamnionitis may not be at an increased risk of delivering an infant with CP.

Isolated umbilical vein varix with a poor outcome despite close fetal surveillance.

A fetal umbilical vein varix is an enlargement of the umbilical vein, which has been previously defined as an index portion of the umbilical vein that is at least 50% wider than the nondilated portion, dilatation of 9 mm or greater, or greater than 2 SDs above the mean for gestational age.1,2 Characteristics frequently described with respect to an umbilical vein varix include the diameter, presence or absence of turbulent flow or hydrops, and presence or absence of other fetal anomalies. More than 100 cases of umbilical vein varices have been reported in the literature, with varying fetal mortality rates.3 Many of the fatal cases have been associated with chromosomal or other anomalies, and some have been associated with intrauterine growth restriction.4 Multiple case series of isolated fetal intraabdominal umbilical vein varices report an average diameter of 12 mm and a range of 8 to 30 mm.2,5 Mankuta et al3 reported that in pregnancies affected by an umbilical vein varix, the rate of intrauterine growth restriction was 10.7%, and 17% of these varices had turbulent flow. Despite the wide range in the size and presence or absence of turbulence, there were no reported cases of intrauterine fetal demise associated with an isolated umbilical vein varix in the series. Other studies have reported an association between the presence of turbulent flow and poor obstetric outcomes.2,6,7 In the following case, we report a pregnancy affected by an isolated fetal umbilical vein varix presenting at 9 mm of dilatation and progressing to 18 mm of dilatation with turbulence. Despite close monitoring, the patient had an intrauterine fetal demise at 32 weeks. The patient was a 27-year-old woman, gravida 2, para 0, with a history of well-controlled hypothyroidism who had a diagnosis of a 9-mm intra-abdominal umbilical vein varix at 23 weeks’ gestation. At the time of diagnosis, there was low turbulent flow within the varix; otherwise, results of a detailed fetal anatomic survey were normal. The remainder of her medical and pregnancy histories were uncomplicated. She was considered low risk for aneuploidy by sequential screening with nuchal translucency measurement and declined amniocentesis after the diagnosis. Another sonographic examination performed at 28 weeks 2 days showed that the varix had increased to 12 to 14 mm with turbulent flow, and a prominent portal vein was seen (Figure 1). Fetal echocardiography performed at 29 weeks did not show any evidence of cardiac abnormalities. A sonographic examination performed at 30 weeks 2 days showed further progression in the size of the umbilical varix and in the dilatation of the portal vein. At this Clinical Letters