Weight gain and pregnancy outcomes in overweight or obese women with twin gestations

Abstract

Background While adequate weight gain in twin pregnancies with normal prepregnancy BMI has been associated with improved pregnancy outcomes, it remains unclear whether adequate weight gain in patients with overweight or obese prepregnancy BMI is associated with similarly improved pregnancy outcomes, and whether this comes at the expense of maternal health risks such as increased risk for gestational diabetes or hypertension. Objective To estimate the association between adherence to weight gain recommendations and pregnancy outcomes in overweight and obese women with twin pregnancies. Methods This is a retrospective cohort study of women with overweight (BMI 25.0–29.9 kg/m2) and obese prepregnancy BMI (≥30.0 kg/m2) and twin pregnancies delivered >24 weeks by a single MFM practice between 2005 and 2017. Baseline characteristics, weight gain patterns, and pregnancy outcomes were compared between women who met or exceeded, and who did not meet gestational weight gain requirements, as recommended by the Institute of Medicine (IOM) in 2009. Since total weight gain is also dependent on gestational age at delivery, we used weight gain per week to define adequate weight gain for overweight (0.85 lb/week) and obese (0.68 lb/week) women. Results A total of 252 overweight and obese women with twin pregnancies met inclusion criteria, 171 (67.9%) of whom met or exceeded weight gain requirements and 81 (32.1%) of whom did not. There were no differences in baseline clinical and demographic characteristics between the two groups. Women with inadequate weight gain had significantly less weight gain in each trimester, as well as less total weight gain for the whole pregnancy. Women with inadequate average gestational weight gain had significantly lower birthweights of the larger twin (2440 versus 2675 g, p = .001) and the smaller twin (2212 versus 2398 g, p = .005), higher incidence of spontaneous preterm birth <37 weeks (33.3 versus 21.1%, p = .03), higher incidence of premature rupture of membranes (24.7 versus 11.7%, p = .008), and greater likelihood of any twin birthweight < 10th percentile for gestational age (51.9 versus 35.5%, p = .01). There were no differences in the likelihood of cesarean delivery, preeclampsia, or gestational diabetes between the two groups. These results did not differ after excluding the 24 women in the cohort with excessive weight gain. Conclusions For overweight and obese women with twin gestations, meeting the IOM recommendations for weight gain in pregnancy is associated with improved pregnancy outcomes. Condensation Women with overweight or obese prepregnancy BMI in twin gestations who gain the recommended amount of weight in pregnancy have improved pregnancy outcomes.