Pregnant women with type 2 diabetes can safely use metformin in the first trimester, according to US epidemiologists who report no increased risk for congenital malformations or non-live births.

The Harvard University-led team say the findings suggest that current recommendations to switch from metformin to insulin during pregnancy based on teratogenicity concerns “may require reconsideration”.

Dr Ka-Kiu Cheung, chair of the RACGP’s antenatal and postnatal care specific interest group, said the study was “timely and welcome” given the limited range of medicines that can be used in pregnancy.

“This research adds weight to the safety profile of metformin previously established in the second trimester and may improve confidence in both clinicians and women who use metformin in pregnancy,” she told AusDoc.