Men's use of diabetes drug just before conception is linked to a 40% increase in birth defects, study find
Metformin, a first-line diabetes drug used for decades, may boost the risk of birth defects in the offspring of men who took it during sperm development,
according to a large Danish study. Sons born to those men were more than three times as likely to have a genital birth defect as unexposed babies,
according to the paper, published in the Annals of Internal Medicine today.
The genital defects, such as hypospadias, when the urethra does not exit from the tip of the penis, were relatively rare,
occurring in 0.9% of all babies whose biological fathers took metformin in the 3 months before conception.
But epidemiologists say the findings are important because tens of millions of people worldwide take metformin, chiefly for type 2 diabetes.
“When I saw the paper … I thought: ‘Yup, this is gonna go viral,’” says Germaine Buck Louis, a reproductive epidemiologist at George Mason University