INTRODUCTION: Women with morbid obesity (body mass index 40 kg/m2 or greater) have an increased risk of stillbirth. Therefore, antenatal testing has been initiated. Data are limited evaluating the obstetrical implications of antenatal testing for morbidly obese women. Our objective was to evaluate the risk of induction and the gestational age of delivery in morbidly obese women undergoing antenatal testing.
METHODS: We performed a retrospective cohort study of women undergoing antenatal testing during 2012 who delivered at our institution. Women were divided into three groups based on antenatal testing indications: group 1: morbid obesity alone, group 2: morbid obesity+comorbidity, group 3: nonmorbid obesity+comorbidity. Our primary outcomes were induction and gestational age of delivery (weeks). Categorical variables were compared with [chi]2 analyses and multivariable logistic regression was used to calculate odds and control for confounders.
RESULTS: Three hundred ninety women were included (group 1=124, group 2=111, group 3=155). The overall induction rate was not significantly different by group (23%, 34%, 34%; P=.08). However, when compared with group 2, group 1 had a lower induction risk (odds ratio [OR] 0.59 [0.34-1.02]), which was significant after controlling for maternal age and race (adjusted OR 0.49 [0.27-0.87]). Group 1 also had a decreased induction risk when compared with group 3 (OR 0.58 [0.34-0.97], adjusted OR 0.49 [0.28-0.85]). There was a significant difference in gestational age of delivery between groups (39.1 weeks in group 1, 38.5 weeks in group 2, 37.9 weeks in group 3, P<.001). Overall cesarean delivery rate was 43% (P=.9).
CONCLUSIONS: Although it remains unknown whether antenatal testing decreases the stillbirth risk in morbidly obese women, this population does not appear to be at increased risk of morbidity as a result of this intervention. Future studies should evaluate neonatal implications for antenatal testing in this group.
(C) 2014 by The American College of Obstetricians and Gynecologists.