Brian L Shaffer

The association between persistent occiput posterior position and neonatal outcomes

OBJECTIVE: To examine the effect of persistent occiput posterior position on neonatal outcome. METHODS: This is a retrospective cohort study of 31,392 term, cephalic, singleton births. Women with neonates born in persistent occiput posterior position at delivery were compared to those with occiput anterior position. Women with occiput transverse position were excluded. The association between occiput posterior position and neonatal outcomes, including 5-minute Apgar scores, umbilical cord gases, meconium-stained amniotic fluid, meconium aspiration syndrome, birth trauma, admission to the intensive care nursery, and length of stay were examined using &khgr;2 and Student t tests. Potential confounders (maternal age, ethnicity, parity, gestational age, epidural anesthesia, labor induction, length of labor, meconium, chorioamnionitis, birth weight, and year of delivery) were controlled for by using multivariable logistic regression and linear regression analyses. RESULTS: There were 2,591 (8.2%) neonates delivered in occiput posterior position of the total cohort of 31,392 deliveries. Compared with occiput anterior, neonates delivered in occiput posterior position had higher risks for adverse outcomes, including 5-minute Apgar score less than 7 (odds ratio [OR] 1.50, 95% confidence interval [CI] 1.17–1.91), acidemic umbilical cord gases (OR 2.05, 95% CI 1.52–2.77), meconium-stained amniotic fluid (OR 1.29, 95% CI 1.17–1.42), birth trauma (OR 1.77, 95% CI 1.22–2.57), admission to the intensive care nursery (OR 1.57, 95% CI 1.28–1.92), and longer neonatal stay in the hospital (OR 2.69, 95% CI 2.22–3.25). CONCLUSION: Persistent occiput posterior position at delivery is associated with higher risks of adverse neonatal outcomes compared with neonates delivered in the occiput anterior position. This information may be important in counseling women who experience persistent occiput posterior position in labor. Level of Evidence: II-2

Labor induction with a foley balloon inflated to 30 mL compared with 60 mL: A randomized controlled trial

OBJECTIVE: To compare 30-mL and 60-mL Foley balloon inflation for labor induction and the effect on length of labor and mode of delivery. METHODS: Women with term, vertex, singleton pregnancies (n=192) and a Bishop score less than 5 were assigned randomly to receive a transcervical Foley balloon inflated to either 30 mL or 60 mL. Exclusion criteria were painful, regular contractions on admission, ruptured membranes, low-lying placenta, or prior hysterotomy. Randomization was stratified by parity, and health care providers were blinded to Foley balloon size. Primary outcome was delivery within 24 hours of Foley balloon placement. Secondary outcomes included delivery within 12 hours, time from Foley balloon placement to expulsion, cervical dilation after Foley balloon expulsion, maximum oxytocin dose, method of delivery, chorioamnionitis, meconium, cervical laceration, abruption, 5-minute Apgar score, and umbilical cord gases. RESULTS: A higher proportion of women randomly assigned to the 60-mL Foley balloon achieved delivery within 12 hours of placement compared with the 30-mL Foley balloon group (26% compared with 14%, P=.04). This difference was more pronounced among nulliparous women. There was no difference in median time interval to delivery or proportion of women who achieved delivery within 24 hours. Median cervical dilation after Foley balloon expulsion was higher in the 60-mL Foley balloon group (4 cm compared with 3 cm, P<.01). There were no differences in the frequencies of cesarean delivery, maternal morbidity, or neonatal outcomes. CONCLUSION: Labor induction using Foley balloons inflated to 60 mL was more likely to achieve delivery within 12 hours compared with 30-mL inflation. There were no differences in delivery within 24 hours, cesarean delivery, labor complications, or neonatal outcomes. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00451308. LEVEL OF EVIDENCE: I

Manual rotation to reduce caesarean delivery in persistent occiput posterior or transverse position

Objective. To examine mode of delivery and perinatal outcomes in women with occiput posterior (OP) or transverse (OT) position in the second stage of labour with a trial of manual rotation compared to expectant management. Methods. A retrospective cohort study was designed to examine mode of delivery and perinatal morbidity in women who underwent a trial of manual rotation (n = 731) compared to expectant management (n = 2527) during the second stage of labour with the fetus in OP/OT position. Chi-square test was used to compare categorical outcomes and multivariable logistic regression models were used to control for potential confounders. Results. Compared to expectant management, women with manual rotation were less likely to have: caesarean delivery (CD) [adjusted odds ratio (aOR) 0.12; 95% confidence interval (CI) 0.09–0.16], severe perineal laceration [aOR 0.64; (0.47–0.88)], postpartum haemorrhage [aOR 0.75; (0.62–0.98)], and chorioamnionitis [aOR 0.68; (0.50–0.92)]. The number of rotations attempted to avert one CD was 4. In contrast, women who had a trial of rotation had an increased risk of cervical laceration [aOR 2.46; (1.1–5.4)]. Conclusions. Compared with expectant management, a trial of manual rotation with persistent fetal OP/OT position is associated with a reduction in CD and adverse maternal outcomes.

Associated factors and outcomes of persistent occiput posterior position: A retrospective cohort study from 1976 to 2001

Objective. To identify maternal and fetal risk factors associated with persistent occiput posterior position at delivery, and to examine the association of occiput posterior position with subsequent obstetric outcomes. Methods. This is a retrospective cohort study of 30 839 term, cephalic, singleton births. Women with persistent occiput posterior (OP) position at delivery were compared to those with occiput anterior (OA) position. Demographics, obstetric history, and labor management were evaluated and subsequent obstetric outcomes examined. Potential confounding variables were controlled for using multivariate logistic regression analysis. Results. The overall frequency of OP position was 8.3% in the study population. When compared to Caucasians, a higher rate of OP was observed among African-Americans (OR = 1.4, 95% CI 1.25–1.64) while no other racial/ethnic differences were noted. Other associated factors included nulliparity, maternal age ≥35, gestational age ≥41 weeks, and birth weight >4000 g, as well as artificial rupture of the membranes (AROM) and epidural anesthesia (p < 0.001 for all). Persistent OP was associated with increased rates of operative vaginal (OR = 4.14, 95% CI 3.57–4.81) and cesarean deliveries (OR = 13.45, 95% CI 11.94–15.15) and other peripartum complications including third or fourth degree perineal lacerations (OR = 2.38, 95% CI 2.03–2.79), and chorioamnionitis (OR = 2.10, 95% CI 1.81–2.44). Conclusion. Epidural use, AROM, African-American ethnicity, nulliparity, and birth weight >4000 g are associated with persistent OP position at delivery, with higher rates of operative deliveries and obstetric complications. This information can be useful in counseling patients regarding risks and associated outcomes of persistent OP position.

Second stage of labor and epidural use: a larger effect than previously suggested.

OBJECTIVE: To examine the length of second stage of labor with and without an epidural during labor. METHODS: This was a retrospective cohort study of 42,268 women who delivered vaginally with normal neonatal outcomes. Median lengths and 95th percentiles of second stage of labor were compared by epidural use with stratification by parity. Statistical comparisons were performed using the Kruskal-Wallis test and Kaplan-Meier survival analysis. RESULTS: Compared with women without epidural use, the 95th percentile length of second stage for nulliparous women was 197 minutes without epidural and 336 minutes with epidural (P<.001), a difference of 2 hours and 19 minutes. For multiparous women, the 95th percentile length of second stage was 81 minutes without epidural and 255 minutes with epidural (P<.001), a difference of 2 hours and 54 minutes. CONCLUSION: Although recommendations for intervention during the second stage of labor have been made based on a 1-hour difference in the setting of epidural use, it appears that the 95th percentile duration is actually more than 2 hours longer with epidural during labor for both nulliparous and multiparous women. LEVEL OF EVIDENCE: II

History of miscarriage and increased incidence of fetal aneuploidy in subsequent pregnancy.

OBJECTIVE: The purpose of this study was to examine the association between history of spontaneous abortion and aneuploidy in a subsequent pregnancy. METHODS: This was a retrospective cohort study of women who underwent fetal karyotype analysis with amniocentesis or chorionic villus sampling at a single prenatal diagnosis center. Information on spontaneous abortions, parity, maternal age, ethnicity, type of prenatal diagnosis, and karyotype was assessed. Univariable and multivariable analyses were conducted. RESULTS: A total of 46,939 women were included in our analysis. Women with no prior spontaneous abortions had a 1.39% risk for any aneuploidy. In women with one prior spontaneous abortion, this risk increased to 1.67%; for women with 2 previous spontaneous abortions, the risk increased to 1.84%; and for those women who had had 3 or more prior spontaneous abortions, the risk increased further to 2.18% (P < .007). When controlling for maternal age, parity, ethnicity, and mode of prenatal diagnosis and compared with women with no prior spontaneous abortions, women with one prior spontaneous abortion (adjusted odds ratio [AOR] 1.21, 95% confidence interval [CI] 1.01–1.47) or 3 or more prior spontaneous abortions (AOR 1.51, 95% CI 1.02–2.25) had a statistically significant increase in aneuploidy in a subsequent pregnancy. Women with 2 prior spontaneous abortions had an AOR of 1.26 for aneuploidy, but the 95% CI contained unity. CONCLUSION: An increased risk of karyotypic abnormality identified at the time of prenatal diagnosis is demonstrated in patients with an increasing number of spontaneous abortions. This study provides information regarding this risk among women presenting for prenatal diagnosis. According to our data, for a woman with an a priori risk of 1 in 300 for Down syndrome, 3 prior spontaneous abortions would increase that risk by 47% to 1 in 204. These results should be confirmed in low-risk populations. LEVEL OF EVIDENCE: II-2

Length of the First Stage of Labor and Associated Perinatal Outcomes in Nulliparous Women

OBJECTIVE: To estimate whether length of the first stage of labor is associated with adverse maternal and neonatal outcomes. METHODS: This is a retrospective cohort study of nulliparous women with term, singleton gestations delivered in one academic center between 1990 and 2008. The length of the first stage was stratified into three subgroups: less than the 5th percentile, 5th to 95th percentile, and greater than the 95th percentile. Maternal and neonatal outcomes were compared using the &khgr;2 test. Multivariable logistic regression models were used to control for confounders. RESULTS: Of the 10,661 nulliparous women meeting study criteria, the median (50th percentile) length of the first stage was 10.5 hours. Compared with women with a first stage between 2.8 and 30 hours (5th to 95th percentile thresholds), the risk of cesarean delivery was higher (6.1% compared with 13.5%; adjusted odds ratio [OR], 2.28, 95% confidence interval [CI], 1.92–2.72) in women with a first stage longer than 30 hours (greater than the 95th percentile). These women also had higher odds of chorioamnionitis (12.5% compared with 23.5%; adjusted OR, 1.58; 95% CI, 1.25–1.98) and neonatal admission to the neonatal intensive care unit (4.7% compared with 9.8%; adjusted OR, 1.53; 95% CI, 1.18–1.97) but no other associated adverse neonatal outcomes. CONCLUSION: Women with a prolonged first stage of labor have higher odds of cesarean delivery and chorioamnionitis, but their neonates are not at risk of increased morbidity. LEVEL OF EVIDENCE: II

Perinatal outcomes in the setting of active phase arrest of labor

OBJECTIVE: To examine the association between active phase arrest and perinatal outcomes. METHODS: This was a retrospective cohort study of women with term, singleton, cephalic gestations diagnosed with active phase arrest of labor, defined as no cervical change for 2 hours despite adequate uterine contractions. Women with active phase arrest who underwent a cesarean delivery were compared with those who delivered vaginally, and women who delivered vaginally with active phase arrest were compared with those without active phase arrest. The association between active phase arrest, mode of delivery, and perinatal outcomes was evaluated using univariable and multivariable logistic regression models. RESULTS: We identified 1,014 women with active phase arrest: 33% (335) went on to deliver vaginally, and the rest had cesarean deliveries. Cesarean delivery was associated with an increased risk of chorioamnionitis (adjusted odds ratio [aOR] 3.37, 95% confidence interval [CI] 2.21–5.15), endomyometritis (aOR 48.41, 95% CI 6.61–354), postpartum hemorrhage (aOR 5.18, 95% CI 3.42–7.85), and severe postpartum hemorrhage (aOR 14.97, 95% CI 1.77–126). There were no differences in adverse neonatal outcomes. Among women who delivered vaginally, women with active phase arrest had significantly increased odds of chorioamnionitis (aOR 2.70, 95% CI 1.22–2.36) and shoulder dystocia (aOR 2.37, 95% CI 1.33–4.25). However, there were no differences in the serious sequelae associated with these outcomes, including neonatal sepsis or Erbs palsy. CONCLUSION: Efforts to achieve vaginal delivery in the setting of active phase arrest may reduce the maternal risks associated with cesarean delivery without additional risk to the neonate. LEVEL OF EVIDENCE: II

Early-onset preeclampsia and neonatal outcomes

Objective. To evaluate the neonatal outcomes of infants delivered to mothers with early-onset preeclampsia. Study design. This is a retrospective cohort of 1709 infants delivered at 24 0/7 to 29 6/7 weeks gestation was examined. Neonatal outcomes of 235 infants delivered prematurely because of preeclampsia were compared with 1474 infants delivered preterm because of other etiologies. Primary outcomes examined included: small for gestational age (SGA), respiratory distress syndrome (RDS), and neonatal death (NND). Multivariable logistic regression was used to analyze the association between preeclampsia and the neonatal outcomes, controlling for potential confounders. Results. Infants of women with preeclampsia were more likely to be SGA (17.8% vs. 5.6%, AOR 3.9, CI 2.5–6.2) and have RDS (70.6% vs. 60.7%, AOR 1.5, 95% CI 1.1–2.2); however, they were less likely to suffer a NND (11.1% vs. 18.1%, AOR 0.6, 95% CI 0.4–0.9). Conclusion. Compared with neonates delivered prematurely because of other etiologies, neonates born to preeclamptic mothers were more likely to be SGA and have RDS, but had a decrease in mortality. This may be a reflection of the differences in the underlying pathophysiology behind indicated preterm birth due to preeclampsia.

Intrahepatic cholestasis of pregnancy and timing of delivery

Abstract Objective: We examined the morbidities from delivery at earlier gestational ages versus intrauterine fetal demise (IUFD) for women with intrahepatic cholestasis of pregnancy (ICP) to determine the optimal gestational age for delivery. Methods: A decision-analytic model was created to compare delivery at 35 through 38 weeks gestation for different delivery strategies: (1) empiric steroids; (2) steroids if fetal lung maturity (FLM) negative; (3) wait a week and retest if FLM negative; or (4) deliver immediately. Literature review identified 18 studies that estimated IUFD in ICP; we used the mean rate, 1.74%, and assumed a uniform distribution from 34 to 40 weeks gestation. Large cohort data was used to calculate neonatal morbidity rates at each gestational age. Maternal and neonatal quality-adjusted life years (QALYs) were combined. Univariate sensitivity and Monte Carlo analyses were performed to test for robustness. Results: Immediate delivery at 36 weeks without FLM testing and steroid administration was the optimal strategy as compared to delivery at 36 weeks with steroids (+47 QALYs) and as compared to immediate delivery at 35 weeks (+210 QALYs). Our results were robust up to a 30% increase in the rate of IUFD. Conclusion: Immediate delivery at 36 weeks in women with ICP is the optimal delivery strategy.