Men taking metformin during sperm development increase risk of genital defects in offspring

Sons born to these men were more than three times as likely to have reproductive organ defects as unexposed babies, according to a paper published in the World Health OrganizationAnnals of Internal MedicineToday

But epidemiologists say the finding is important because tens of millions of people around the world take metformin, mainly to treat type 2 diabetes

He wrote an editorial attached to the report"[Metformin] is even widely used by young people because we have obesity

In addition to metformin, other factors may have influenced the findings, they added

A change in any medication 'is a complex decision a couple should takewith their doctorhe said

In 2004, 41 million prescriptions were written in the United States;by 2019The number is 86 million.

While metformin use tends to skew older, the rise in diabetes means more men are taking the drug during their reproductive years

In the offspring of 1,451 men who were prescribed metformin 90 days before conception, the period during which spermatogenesis occurs, they found a 5.

The increased risk is much greater in male infants onlyAmong exposed infants, 0.

But after the researchers adjusted for factors including parental age and maternal smoking status, they found a 3.

"It really has to do with window injections during sperm development," said senior author Michael Eisenberg, a urologist at Stanford University School of Medicine

All of these findings suggest that the drug's effect on sperm formation, rather than diabetes or other factors inherent in men, is the cause

Scientists are also unsure how exactly the drug affects sperm

ResearchThere are mice in the fishHinting that metformin can disrupt male reproductive organ development, a small study finds that metforminDecreased serum testosterone levelson men

"This paper is the first word, not the last," said Russell Kirby, a birth defect epidemiologist at the University of South