Metformin in pregnancy and lactation

Abstract

Metformin improves insulin sensitivity and reduces hepatic glucose output in patients with diabetes. It offers potential benefits for pregnant women with gestational or type 2 diabetes because both conditions are associated with increased insulin resistance. Some cohort data are available and randomised trials are currently in progress to compare metformin with insulin, but strong evidence is not yet available to guide management. There are no long-term follow-up data to provide reassurance about the safety of metformin, given its passage across the placenta, although recent evidence suggests that there is no significant risk of teratogenesis. limited amounts of metformin are transferred into breast milk, but the risk of neonatal hypoglycaemia is negligible.