Associations of pre-pregnancy obesity with adverse pregnancy outcomes and the optimal gestational weight gain in Japanese women

Abstract

The authors determined associations of maternal pre-pregnancy obesity with adverse pregnancy outcomes and evaluated how gestational weight gain affects risks for such outcomes in Japanese obese pregnant women. Among women who delivered at the Perinatal Center for Maternity and Neonatal, Yokohama City University Medical Center, between January 2001 and December 2012, the authors ascertained adverse pregnancy outcome incidences in 207 pre-pregnancy obese (body mass index [BMI] = 30 kg/m², obese group), 661 pre-pregnancy overweight (BMI = 25-29.9 kg/m², overweight group), and 6,801 pre-pregnancy normal weight (BMI= 18.5-24.9 kg/m², normal group) women. Subjects were stratified by weekly weight gain during the second/third trimesters to investigate associations between gestational weight gain and adverse pregnancy outcomes. Optimal weight gain for obese pregnant women was also examined. In the obese and overweight groups, incidences of pregnancy induced hypertension (PIH), gestational diabetes mellitus (GDM), large for gestational age (LGA), preterm birth, preterm prelabor rupture of membranes (PPROM), and spontaneous preterm birth were significantly higher than in the normal group. Incidences of adverse pregnancy outcomes were ap- parently higher in the obese than in the overweight group. In the latter, the incidence of large for gestational age was significantly higher in women with weight gains of 0.5 kg/week, whereas no difference in pregnancy outcomes was observed in the obese group regardless of gestational weight gain. In obese women, incidences of adverse pregnancy outcomes were higher, and pregnancy out- comes were difficult to improve with gestational weight control. Thus, it.is important to reach an optimal weight before pregnancy.