Glycemic Level Modifies the Relationship Between Maternal Gestational Weight Gain and Neonatal Birth Weight in Type 2 Diabetes–Complicated Pregnancies

OBJECTIVETo examine whether glycemic level modifies the association between gestational weight gain (GWG) and pregnancy outcomes in type 2 diabetes–complicated pregnancies.RESEARCH DESIGN AND METHODSThis multicenter retrospective study stratified 1,642 pregnant women with diabetes by third-trimester glycemic control. Associations between excessive GWG (eGWG) and pregnancy outcomes were analyzed by group.RESULTSAlthough birth weight and odds of macrosomia and cesarean delivery were higher for all women with eGWG relative to those with adequate GWG, the effect estimates for birth weight and macrosomia were significantly higher with suboptimal glycemic control compared with optimal control (birth weight increase: 361.04 vs. 126.07 g, respectively, P = 0.007; adjusted odds ratio for macrosomia: 4.26 vs. 2.73, P = 0.002; cesarean delivery: 1.86 vs. 1.52, P = 0.738).CONCLUSIONSOverly stringent weight control should be treated with caution if optimal glycemic control is not achieved.