Objective: To determine rates of maternal and perinatal outcomes after induction of labor (IOL) at 39 weeks compared with expectant management.Methods: Cohort study of low risk women delivered between 39-42 weeks from 2015 to 2018. We excluded births with fetal abnormalities, previous cesarean, multiple pregnancies or those with spontaneous onset of labor (SOL) or indicated delivery at 39 weeks. Data was abstracted from National Center for Health Statistics birth les. Relative risks (aRR) were estimated with multivariable log-binomial regression.Main Outcome Measures: Maternal outcomes: chorioamnionitis (Triple I), blood transfusion, neonatal intensive care unit (NICU) admission, uterine rupture, cesarean delivery and cesarean hysterectomy. Fetal and infant outcomes: fetal death, 5-minute Apgar ≤3, prolonged ventilation, seizures, ICU admission, and death within 28 days.Results: There were 15,900,956 births, with 8,540,063 after exclusions. The IOL group included 1,177,790 births excluding women with diabetes or hypertensive disease. There were 3,835,185 births after 39 weeks excluding women with diabetes or chronic hypertension. With IOL at 39 weeks the risk for blood transfusion (p-value < 0.01; aRR 0.78; 95% CI [0.75-0.82]), Triple I (p-value < 0.01; aRR 0.71; 95% CI [0.70-0.73]) and cesarean delivery (p-value <0.01; aRR 0.87; 95% CI [0.87-0.88]) were lower, albeit increased risk of cesarean hysterectomy (p-value <0.01; aRR 1.23; 95% CI [1.07-1.41]). Neonates had a lower risk for 5minute Apgar ≤3 (p-value < 0.01; aRR 0.68; 95% CI [0.66-0.71]), prolonged ventilation (p-value < 0.01; aRR 0.84; 95% CI [0.81-0.87]), NICU admission (p-value < 0.01; aRR 0.86; 95% CI [0.85-0.87]), and neonatal seizures (p-value <0.01; aRR 0.85; 95% CI [0.76-0.96]). There was no difference in risk for neonatal death 0.99% (p-value 0.99; aRR 1.00; 95%CI [0.99-1.00]), or fetal death aRR 1.0002;]. This bene t was greater compared with each subsequent week.Conclusions: Induction of labor at 39 weeks of gestation in a low risk cohort is associated a lower risk of cesarean delivery, transfusions and infection, as well as lower neonatal morbidity, without difference in fetal or neonatal death. This appears to be associated with increased risk for cesarean hysterectomy.

Objective: To determine maternal and neonatal morbidity associated with induction of labor at 39 weeks compared with expectant management through 42 weeks. Design: Cohort study Setting & Population: Low risk American women who delivered between 39 and 42 weeks in 2015 to 2017. Methods: Data was abstracted from the national vital statistics database. Multivariable log-binomial regression analysis was conducted to estimate the relative risk of morbidity. Main Outcome Measures: Maternal morbidity included Triple I, blood transfusion, ICU admission, uterine rupture, cesarean hysterectomy, and cesarean delivery. Neonatal morbidity included 5 minute Apgar ≤3, prolonged ventilation, seizures, NICU admission, and neonatal death. Results: A total of 1,885,694 women were included for analysis. Women undergoing induction of labor at 39 weeks were less likely to develop Triple I (p-value < 0.001; aRR 0.66; 95% CI [0.64-0.68]) and require a cesarean section (p-value <0.01; aRR 0.69l 95% CI [0.68-0.69]) than the expectant management group. There was a small, but significant increase in cesarean hysterectomy in the induction group (p-value <0.01; aRR 1.32; 95% CI [1.05-1.65]). Neonates of the induction group were less likely to have 5 minute Apgar ≤3 (p-value < 0.01; aRR 0.69; 95% CI [0.64-0.74]), prolonged ventilation (p-value < 0.01; aRR 0.77; 95% CI [0.72-0.82]), NICU admission (p-value < 0.01; aRR 0.80; 95% CI [0.79-0.82]), and/or neonatal seizures (p-value <0.01; aRR 0.80; 95% CI [0.66-0.98]) compared to the expectant management group. Conclusions: Induction of labor at 39 weeks gestation compared with expectant management is not harmful and has maternal and neonatal benefits.

INTRODUCTION: To investigate the risk of perinatal death associated with induction of labor (IOL) at 39 weeks versus expectant management (EM). METHODS: This was a retrospective cohort analysis of singleton non-anomalous liveborn pregnancies in the United States between January 2015 and December 2017. Data was abstracted from the CDC National Center for Health Statistics from the Division of Vital Statistics. Analyses compared IOL at 39 weeks of gestation to EM with delivery between 40 and 42 weeks of gestation. Year over year rates of IOL and perinatal death were calculated and tested for trend over time. The risk of perinatal death associated with IOL compared to EM was estimated using logistic-binomial regression analysis, adjusting for potential confounders. RESULTS: There were 1,987,757 pregnancies included for analysis. 499,290 (25.1%) pregnancies were induced at 39 weeks. The year over year risk of IOL was 1.04 (95% CI 1.03–1.04). Conversely, the year over year risk of perinatal death was 0.96 (95% CI 0.94–0.99). There was a year over year decrease in risk of neonatal death, aRR: 0.91 (95% CI 0.85–0.96). In the IOL group there were 184 (0.04%) perinatal deaths compared to 2,421 (0.16%) in the EM group, (P<.001; aRR: 0.22, 95% CI 0.19–0.26). CONCLUSION: There was a year over year increase in IOL. Additionally, there was a year over year decrease in perinatal death, primarily due to a decrease in neonatal deaths. IOL at 39 weeks was associated with a decreased risk of perinatal death compared EM.

INTRODUCTION: To compare the risk of maternal complications associated with induction of labor (IOL) at 39 weeks gestation with that of expectant management (EM) beyond 39 weeks gestation. METHODS: This is a retrospective cohort analysis of singleton non-anomalous pregnancies in the United States between January 2015 and December 2017. Data was abstracted from the CDC National Center for Health Statistics from the Division of Vital Statistics. Analyses compared IOL at 39 weeks of gestation versus EM with delivery between 40 and 42 weeks of gestation. Maternal outcomes of interest included need for blood transfusion, development of chorioamnionitis, intensive care unit (ICU) admission, uterine rupture, unplanned hysterectomy, and cesarean delivery (CD). Logistic-binomial regression analysis was performed to calculate the relative risk for the outcomes of interest, adjusting for confounding variables. RESULTS: There were 1,987,757 pregnancies included for analysis with 499,920 women in the IOL group. The risk of chorioamnionitis was 1.39% for IOL and 2.47% for EM (aRR: 0.58, 95% CI [0.56-0.59]). The risk of CD was 14.7% in the IOL group versus 14.8% in the EM group (aRR: 0.94, 95% CI [0.93-0.94]). Unplanned hysterectomy in the IOL group was 0.03% versus 0.02% in the EM group (aRR: 1.30, 95% CI [1.05-1.59]). There were no differences in risk of blood transfusion, ICU admission, and uterine rupture between the IOL and EM groups. CONCLUSION: Women who underwent IOL at 39 weeks had a lower risk of chorioamnionitis and CD compared to EM. However, there was a higher risk of unplanned hysterectomy with IOL at 39 weeks.