Obesity is a known risk factor for infectious morbidity after cesarean delivery. Nulliparous women often require prolonged inductions of labor, which increases the length of membrane rupture and risk for chorioamnionitis. Therefore, we sought to evaluate if the risk for chorioamnionitis was increased in obese women based on length of membrane rupture.
This study was conducted on a retrospective cohort of term, nulliparous patients with singleton gestations requiring non-elective cesarean sections after induction of labor at a single academic institution from 2008 to 2015. The primary outcome was the incidence of chorioamnionitis. Secondary outcomes included endometritis and cesarean wound infection. Maternal obesity, defined as body mass index (BMI) >30 kg/m2, and duration of amniotic membrane rupture, were evaluated as the primary risk factors.
A total of 297 patients met inclusion criteria. Increased duration of membrane rupture was associated with increased risk of chorioamnionitis (Odds ratio [OR] 1.08 95% Confidence Interval [CI] 1.05-1.11). However, increasing BMI was not associated with increased risk of chorioamnionitis, and regression analysis showed there was no significant relationship between BMI and the interval between rupture of amniotic membranes and delivery (R-sq 1.2%). Secondary analysis did reveal significantly higher risk of chorioamnionitis with IUPC use ([OR] 3.12 [CI] 1.4258, 6.7918).
Maternal obesity does not appear to independently increase the length of ruptured membranes and the rate of chorioamnionitis during induction of labor. However, obese patients undergoing a prolonged induction of labor are more likely to be monitored with an IUPC, which increases their chorioamnionitis risk.
Albany Medical Center, Albany, NY
Financial Disclosure: The authors did not report any potential conflicts of interest.