Popular diabetes drug Metformin linked to birth defects in baby boys: study
- The medication was associated with a 1.4 times greater risk of birth defects in boys whose fathers were taking it compared with those born to men who were not
- Researchers said more study was needed, but suggested that men taking metformin consider switching to another treatment when trying to conceive
One of the world’s most widely prescribed diabetes drugs may be linked to major birth defects in the offspring of male patients who were taking it ahead of the babies being conceived, according to a new study from Denmark released on Monday.
Metformin, among the most common and often initially prescribed treatments for type 2 diabetes, was associated with a 1.4 times greater risk of birth defects in boys whose fathers were taking the drug compared with those born to fathers who were not, researchers from the University of Southern Denmark and Stanford University in the United States found.
In both groups, the mothers had no history of diabetes or hypertension.
The study’s authors, as well as independent experts, pointed to several key limitations of the data published in the Annals of Internal Medicine.
Researchers did not know whether the fathers took the medication as prescribed, or if they had worse control of their diabetes, which could also be linked to a higher risk of birth defects. The study showed that the risk for babies born to men taking insulin rather than metformin were not increased.
Channa Jayasena, head of andrology at Imperial College London, who was not involved in the work, called the results “thought-provoking but inconclusive”.