Induction of Labor at 39 Weeks and the Risk of Perinatal Death [19P

Abstract

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.