Influence of maternal overweight, obesity and gestational weight gain on the perinatal outcomes in women with gestational diabetes mellitus.

To assess the associations between maternal body mass index (BMI) as well as gestational weight gain (GWG) and pregnancy outcomes in women with gestational diabetes mellitus (GDM). This is a retrospective analysis involving 832 nulliparous women complicated with GDM. Multivariate logistic and restricted cubic logistic regression were used to investigate the association of interest. Overall, 178 (21.4%) women were overweight or obese, and 298 (35.2%) exhibited excessive GWG. Compared with women of normal weight, high pre-pregnancy BMI resulted in a higher risk of cesarean section with an adjusted odds ratio of 1.95 (95% confidence interval being 1.29-2.96) for overweight group and 3.26 (1.57-6.76) for obese group. Similarly, the respective aORs were 4.10 (1.56-10.81) and 9.78 (2.91-32.85) for gestational hypertension, 2.02 (1.05-3.88) and 8.04 (3.46-18.66) for macrosomia, 2.14 (1.40-3.26) and 3.34 (1.69-6.60) for large for gestational age (LGA). Compared with adequate GWG, excessive GWG increased the incidence of cesarean section (1.60, 1.15-2.23) and macrosomia (1.94, 1.11-3.38), while inadequate GWG reduced the incidence of LGA (0.29, 0.17-0.51). High pre-pregnancy BMI and excessive GWG were associated with higher incidence of LGA, as well as other adverse outcomes in women with GDM. Narrower guidelines on GWG might offer extra safety benefit in gestational diabetic population.