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

Aims: Our 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. Methods: 460 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. Results: Women 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. Conclusions: Restricted GWG among women with type 2 diabetes is associated with both benefits and harms. Both must be considered when counseling patients.

Automated summary

This study assesses perinatal outcomes among women with type 2 diabetes and analyzes gestational weight gain. The study found that restricted weight gain has both benefits and harms, highlighting the importance of comprehensive counseling for patients.