Higher pre-pregnancy body mass index is associated with excessive gestational weight gain in normal weight Chinese mothers with gestational diabetes.

Objective: To assess how pre-pregnancy body mass index (BMI) affects pregnancy outcome and total gestational weight gain (GWG) in a cohort of women with gestational diabetes (GDM).

Methods: Pregnant women at 24-28 gestational weeks diagnosed with GDM were classified as normal weight (pre-pregnancy BMI, 18.5-24.9 kg/m(2) ) or overweight (pre-pregnancy BMI, 25.0-29.9 kg/m(2) ). GWG was derived from the self-reported pre-pregnancy and pre-delivery weights, and analyzed using 2009 Institute of Medicine categories.

Results: A total of 106 GDM women were categorized as normal weight (n = 79) or overweight (n = 27). No statistically significant differences were found between the groups in terms of various obstetrical and neonatal outcomes. Higher pre-pregnancy BMI, however, was associated with excessive GWG during pregnancy (difference between groups, P = 0.013). Furthermore, pre-pregnancy BMI (OR, 0.529; 95%CI: 0.377-0.742; P = 0.000) and pre-pregnancy overweight (OR, 3.825; 95%CI: 1.469-9.959; P = 0.006) were independent factors of GWG.

Conclusions: Among Chinese GDM women, overweight GDM mothers gain excessive weight during pregnancy. Regulation of pre-pregnancy bodyweight might be an appropriate precaution against excessive GWG.