Gestational weight gain in women with type 2 diabetes and perinatal outcomes: A secondary analysis of the metformin in women with type 2 diabetes in pregnancy (MiTy) trial

Abstract

AimsOur study assesses perinatal outcomes among women with type 2 diabetes, with gestational weight gain (GWG) within and outside of US Institute of Medicine (IOM) guidelines, by conducting a secondary analysis of the Metformin in Type 2 Diabetes in Pregnancy (MiTy) trial. Methods460 participants were classified into three cohorts by total and weekly GWG (excessive, appropriate vs. restricted according to IOM). The primary outcome was birthweight z score, and secondary outcomes included both maternal and fetal outcomes. ResultsWomen with restricted (total and weekly) GWG had lower birthweight z score, lower fetal birthweight, and lower neonatal body fat mass. Women with restricted weekly GWG had fewer LGA, extreme LGA, and lower neonatal body fat mass infants, but more SGA and preterm births. Women with excessive (total and weekly) GWG had higher maternal total insulin doses in the third trimester. Women with excessive weekly GWG had more preeclampsia and higher SGA. ConclusionsRestricted GWG among women with type 2 diabetes is associated with both benefits and harms. Both must be considered when counseling patients.