Metformin use in gestational diabetes is not associated with an increased risk of preterm labor and small for gestational age infants compared to diet control alone.

Abstract

Aims: Given the limited data on the effects of metformin exposure in pregnancy, this study aims to investigate the association between metformin use in Gestational Diabetes (GDM) and the risk of short-term maternal and neonatal outcomes.

Methods: This retrospective cohort study included women with GDM who sought prenatal care at Sidra Medicine, Qatar, between January 2019 and December 2020 and compared maternal and neonatal outcomes in patients treated with metformin to those treated with diet control alone.

Results: Six hundred forty nine GDM patients were included, of which 438 were treated with diet only, and 211 were treated with metformin. At baseline, the metformin-treated group was older (33.3 ± 4.8 vs. 31.2 ± 5.0 years), had higher pre-pregnancy Body Mass Index (BMI) (27.9 ± 4.6 vs. 26.0 ± 4.7 kg/m²), but had lower gestational weight gain (0.28 ± 0.20 vs. 0.34 ± 0.17 kg/week) than the diet group (p <.001). When adjusted for age, fasting glucose at diagnosis, pre-pregnancy weight, and gestational weight gain, metformin treatment was not associated with an increased risk of any adverse pregnancy outcomes.

Conclusions: Treatment with metformin was not associated with an increased risk of adverse outcomes, including small for gestational age and preterm labor in women with GDM.