Interpregnancy Body Mass Index Change and Risk of Intrapartum Cesarean Delivery

Abstract

Objective This study aimed to examine the association between interpregnancy body mass index (BMI, kg/m2) change and intrapartum cesarean delivery in multiparous women without a history of cesarean delivery. Study Design We conducted a retrospective cohort study of all women who had more than one singleton pregnancy at 23 weeks' gestation or greater at MedStar Washington Hospital Center from January 2009 to June 2018. We excluded women who had a history of cesarean delivery, prelabor cesarean delivery, and contraindications for vaginal delivery. Interpregnancy BMI change was calculated by the change of early pregnancy BMI measured in the office. Women were categorized according to the interpregnancy BMI change (BMI loss more than 2 kg/m2, BMI change ± 2 kg/m2, and BMI gain more than 2 kg/m2). The primary outcome was an intrapartum cesarean delivery. Multivariable logistic regression was performed to calculate adjusted odds ratio (aOR) with 95% confidence interval (CI) after adjusting for predefined covariates. Results Of 2,168 women who were analyzed, 258 (12%), 1,192 (55%), and 718 (33%) had interpregnancy BMI loss more than 2 kg/m2, BMI change ± 2 kg/m2, and BMI gain more than 2 kg/m2, respectively. Women with BMI gain more than 2 kg/m2 compared with those with BMI change ± 2 kg/m2 had increased odds of intrapartum cesarean delivery (7.4 vs. 4.5%; aOR: 1.78; 95% CI: 1.10–2.86) and cesarean delivery for arrest disorders (3.1 vs. 1.1%; aOR: 3.06; 95% CI: 1.30–7.15). Women with BMI loss more than 2 kg/m2 compared with those with BMI change ± 2 kg/m2 had similar rates of cesarean delivery. Conclusion Compared with interpregnancy BMI change ± 2 kg/m2, interpregnancy BMI gain 2 kg/m2 was associated with increased odds of intrapartum cesarean delivery. Key Points