Men can take the widely prescribed diabetes medication metformin without concerns about causing birth defects in their children, according to a large study published recently. Researchers tracked over three million pregnancies in Norway and Taiwan and found no association between birth defects and paternal use of metformin during the three months before conception, the critical period for sperm development.
Metformin is commonly prescribed as the first-line treatment for Type 2 diabetes, the most prevalent form of the disease, and is generally considered an inexpensive generic medication.
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A previous study conducted in Denmark in 2022 suggested that there was a 1.4 times greater risk of birth defects in boys born to fathers taking metformin. However, subsequent studies have failed to confirm this link. In June, two studies published in the Annals of Internal Medicine concluded that neither maternal nor paternal use of metformin increases the risk of congenital malformations.
The new study’s findings, which draw on data from two distinct populations, bolster its conclusions. Dr. Allan Pacey, an expert in male reproductive health at the University of Manchester, emphasized that the lack of a biological mechanism to support a link between metformin use by fathers and birth defects makes the results logical. He noted that the new research benefited from improved data quality, allowing for a more thorough consideration of confounding factors compared to the earlier Danish study.
Pacey concluded that the recent findings are significant and reassuring for men with diabetes concerned about the potential impacts of metformin on their offspring.
