Abstract
INTRODUCTION:Our objective was to characterize gestational weight gain and postpartum weight retention in term twin pregnancies by body mass index (BMI) and trimester.
METHODS:Retrospective cohort study including all term twin pregnancies at the University of California, San Diego Medical Center 2009–2013. Adequate gestational weight gain was determined by the 2009 Institute of Medicine guidelines for twin pregnancies. Studentʼs t test and the χ test were used for analyses.
RESULTS:Fifty-nine term twin pregnancies met inclusion criteria. Mean gestational weight gain for the cohort was 16.6±5.1 kg. According to Institute of Medicine guidelines, 15% had insufficient, 39% had sufficient, and 46% had excessive gestational weight gain. There were no differences in total gestational weight gain by chorionicity or BMI. The mean rates of gestational weight gain were 0.5±0.2 kg per week until 20 weeks of gestation, 0.7±0.3 kg per week at 20–28 weeks of gestation, and 0.7±0.4 kg per week from 28 weeks of gestation to term. Comparing rates of gestational weight gain between BMI groups, there were significant differences in rates of gestational weight gain before 20 weeks of gestation but no differences at 20–28 weeks of gestation and from 28 weeks of gestation to term. At the postpartum visit, 74% of normal, 93% of overweight, and 33% of obese women were within 5 kg of their first pregnancy weight (P=.02).
CONCLUSIONS:The majority of twin pregnancies have sufficient gestational weight gain during their pregnancies and 46% exceed guidelines. Contrary to singletons, pregravid BMI does not adversely affect gestational weight gain. Beyond 20 weeks of gestation, gestational weight gain for women of different BMI groups occurs at similar rates. However, obesity is associated with a higher risk of postpartum weight retention in twin pregnancies.