Boston, MA – New research suggests that concerns about a potential link between the type 2 diabetes drug metformin and an increased risk of birth defects may not be as significant as previously thought. Two studies published in the Annals of Internal Medicine contradict earlier research indicating an increased risk of birth defects in babies born to fathers who used metformin before conception.
Dr. Ran Rotem, a researcher at the Harvard T.H. Chan School of Public Health, emphasized the importance of considering the father’s health in pregnancy outcomes. The new studies provide assurance to parents, indicating that paternal use of metformin does not appear to be associated with an increased risk of major birth defects in children.
Metformin, a first-line medication for type 2 diabetes, has been widely used since the 1960s to help control blood sugar levels. Before taking metformin, individuals are advised to inform their doctor if they plan to become pregnant, are pregnant, or are breastfeeding.
Research analyzing data on nearly 400,000 babies born in Israel between 1999 and 2020 found no increased risk of major birth defects in children exposed to paternal metformin. When adjusting for various factors, including underlying health conditions, no elevated risk of birth defects was observed in children exposed to paternal metformin.
The findings also indicated that men using diabetes medications during the sperm developmental period tended to have older ages, higher prevalence of underlying health conditions, fertility problems, and a history of smoking. However, paternal use of metformin alone did not increase the risk of birth defects, compared to using metformin with other medications.
On the maternal side, women who continued using metformin and added insulin in the first trimester of pregnancy showed little to no increased risk of birth defects in their babies. The studies suggest that metformin is a safe and effective treatment option for individuals with type 2 diabetes planning to conceive.
Overall, the new research underscores the importance of considering both paternal and maternal health when evaluating the risks and benefits of metformin use during pregnancy. It may be time to reconsider current guidelines that recommend switching to insulin therapy, as metformin has shown to be a safe option for managing hyperglycemia in pregnant women.