Risk of cesarean delivery among pregnant women with class III obesity

To identify factors associated with cesarean delivery among women with class III obesity attempting vaginal delivery.

In a retrospective study, medical charts were reviewed for women aged 18 years or older with a singleton pregnancy of at least 37 weeks and a body mass index (calculated as weight in kilograms divided by the square of height in meters) of 40 or higher who were eligible to attempt vaginal delivery at a maternity hospital in Lille, France, between 1999 and 2012.

Among 345 eligible women, 301 (87.2%) attempted vaginal delivery; 211 (70.1%) were successful and 90 (29.9%) delivered by cesarean. The frequency of nulliparity was higher among those undergoing cesarean after a trial of labor (64 [71.1%]) than among those who delivered vaginally (57 [27.0%]; P<0.001). Induction of labor was also more frequent among those who ultimately delivered by cesarean (61 [67.8%] vs 96 [45.5%]; P<0.001). In multivariate analysis, induction of labor was an independent predictor of cesarean among women attempting vaginal delivery (odds ratio [OR] 2.30, 95% confidence interval [CI] 1.25-4.22), whereas history of vaginal delivery was protective (OR 0.08, 95% CI 0.04-0.17).

Nulliparous women with class III obesity attempting a vaginal delivery should be warned of the high risk of cesarean delivery, especially if they require induction.