Optimal Plan for Delivery in Women with Obesity: A Large Population-based Retrospective Cohort Study Using the Better Outcomes Registry and Network (BORN) Database

Abstract

Abstract Objective: To discern the optimal plan for delivery in nulliparous women with obesity at term gestation. Subjects/Methods: This was a large population-based retrospective cohort study. It included nulliparous women with obesity (BMI>30) giving birth at a maternity hospital in Ontario, Canada with live, singleton, uncomplicated term gestations (37+0 to 41+6 weeks) between April 1st, 2012 and March 31st, 2019. A total of 27 472 deliveries were included.Interventions/Methods: Women were divided by plan for delivery (expectant management, induction of labour and no-labour caesarean section). The primary outcome was the Adverse Outcome Index (AOI), a binary composite of 10 maternal and neonatal adverse events. The Weighted Adverse Outcome Score (WAOS) was the secondary outcome. It provides a weighted score of each adverse event included in the AOI. Analyses were conducted using multivariable regression models. Analyses were stratified by each week of gestational age and by obesity class. Results No-labour caesarean section reduced the risk of adverse delivery outcome by 41% (aRR 0.59, 95%CI [0.50, 0.70]) compared to expectant management at term gestation. There was no statistically significant difference in adverse birth outcomes when comparing induction of labour to expectant management (aRR 1.03, 95% CI [0.96, 1.10]). The greatest benefit to no-labour caesarean section was observed in the reduction of adverse neonatal events (aRR 0.70, 95% CI [0.57, 0.87]) after 39 weeks of gestation. Conclusion In women with obesity, no-labour caesarean section reduces adverse birth outcomes.