The Effect of Maternal Obesity on Oxytocin Requirements to Achieve Vaginal Delivery.

OBJECTIVE: Our objective was to determine if obese women are more likely to require oxytocin rates > 20 mU/min to achieve vaginal delivery, compared with normal weight women. STUDY DESIGN: This is a retrospective cohort study of deliveries at the MedStar Washington Hospital Center and MedStar Georgetown University Hospital. RESULTS: There were 4,284 births included in the analysis. Thirty-three per cent of deliveries were among women classified as overweight (body mass index [BMI] 25-29.9 kg/m2) and 58% were among women classified as obese (BMI >30.0 kg/m2), 12% were classified as class III obesity (BMI >40 kg/m2). Overall 110 (2.6%) women required an oxytocin rate of >20 mU/min. Doses of oxytocin >20 mU/min for women in the overweight, class I obesity, and class II obesity groups were 2.6, 1.9, and 1.6%, respectively. Deliveries among women with class III obesity had a significantly longer duration of oxytocin exposure (10.7 hours) compared with the normal weight group (8.2 hours, p < 0.001), and had a higher maximum rate of oxytocin compared (10 mU/min) to normal weight women (8 mU/min, p < 0.001). CONCLUSION: Obese women are more likely to require oxytocin rates more than 20 mU/min, higher doses of oxytocin, and greater duration of oxytocin exposure to achieve a vaginal delivery.

Early preterm preeclampsia outcomes by intended mode of delivery.

BACKGROUND: The optimal route of delivery in early-onset preeclampsia before 34 weeks is debated because many clinicians are reluctant to proceed with induction for perceived high risk of failure. OBJECTIVE: Our objective was to investigate labor induction success rates and compare maternal and neonatal outcomes by intended mode of delivery in women with early preterm preeclampsia. STUDY DESIGN: We identified 914 singleton pregnancies with preeclampsia in the Consortium on Safe Labor study for analysis who delivered between 24 0/7 and 33 6/7 weeks. We excluded fetal anomalies, antepartum stillbirth, or spontaneous preterm labor. Maternal and neonatal outcomes were compared between women undergoing induction of labor (n = 460) and planned cesarean delivery (n = 454) and women with successful induction of labor (n = 214) and unsuccessful induction of labor (n = 246). We calculated relative risks and 95% confidence intervals to determine outcomes by Poisson regression model with propensity score adjustment. The calculation of propensity scores considered covariates such as maternal age, gestational age, parity, body mass index, tobacco use, diabetes mellitus, chronic hypertension, hospital type and site, birthweight, history of cesarean delivery, malpresentation/breech, simplified Bishop score, insurance, marital status, and steroid use. RESULTS: Among the 460 women with induction (50%), 47% of deliveries were vaginal. By gestational age, 24 to 27 6/7, 28 to 31 6/7, and 32 to 33 6/7, the induction of labor success rates were 38% (12 of 32), 39% (70 of 180), and 54% (132 of 248), respectively. Induction of labor compared with planned cesarean delivery was less likely to be associated with placental abruption (adjusted relative risk, 0.33; 95% confidence interval, 0.16-0.67), wound infection or separation (adjusted relative risk, 0.23; 95% confidence interval, 0.06-0.85), and neonatal asphyxia (0.12; 95% confidence interval, 0.02-0.78). Women with vaginal delivery compared with those with failed induction of labor had decreased maternal morbidity (adjusted relative risk, 0.27; 95% confidence interval, 0.09-0.82) and no difference in neonatal outcomes. CONCLUSION: About half of women with preterm preeclampsia who attempted an induction had a successful vaginal delivery. The rate of successful vaginal delivery increases with gestational age. Successful induction has the benefit of preventing maternal and fetal comorbidities associated with previous cesarean deliveries in subsequent pregnancies. While overall rates of a composite of serious maternal and neonatal morbidity/mortality did not differ between induction of labor and planned cesarean delivery groups, women with failed induction of labor had increased maternal morbidity highlighting the complex route of delivery counseling required in this high-risk population of women.

Risk factors for retained placenta.

OBJECTIVE: Retained placenta complicates 2-3% of vaginal deliveries and is a known cause of postpartum hemorrhage. Treatment includes manual or operative placental extraction, potentially increasing risks of hemorrhage, infections, and prolonged hospital stays. We sought to evaluate risk factors for retained placenta, defined as more than 30 minutes between the delivery of the fetus and placenta, in a large US obstetrical cohort. STUDY DESIGN: We included singleton, vaginal deliveries ≥24 weeks (n = 91,291) from the Consortium of Safe Labor from 12 US institutions (2002-2008). Multivariable logistic regression analyses estimated the adjusted odds ratios (OR) and 95% confidence intervals (CI) for potential risk factors for retained placenta stratified by parity, adjusting for relevant confounding factors. Characteristics such as stillbirth, maternal age, race, and admission body mass index were examined. RESULTS: Retained placenta complicated 1047 vaginal deliveries (1.12%). Regardless of parity, significant predictors of retained placenta included stillbirth (nulliparous adjusted OR, 5.67; 95% CI, 3.10-10.37; multiparous adjusted OR, 4.56; 95% CI, 2.08-9.94), maternal age ≥30 years, delivery at 24 0/7 to 27 6/7 compared with 34 weeks or later and delivery in a teaching hospital. In nulliparous women, additional risk factors were identified: longer first- or second-stage labor duration, whereas non-Hispanic black compared with non-Hispanic white race was found to be protective. Body mass index was not associated with an increased risk. CONCLUSION: Multiple risk factors for retained placenta were identified, particularly the strong association with stillbirth. It is plausible that there could be something intrinsic about stillbirth that causes a retained placenta, or perhaps there are shared pathways of certain etiologies of stillbirth and a risk of retained placenta.