New research shows that men who take metformin are more likely to have babies born with defects. There is some hope though as experts say the risk only exists when men take cheap diabetes drugs during the time of conception.
The research showed that defects were roughly 40 percent more common among infants whose fathers were prescribed the medication.
The study found that babies born to men who took metformin during the time of sperm development were at increased risk for birth defects. The most common issue was genital defects in boys. The research clearly suggests that men with diabetes who are taking metformin should talk to their doctors about whether they should switch to another treatment when trying to conceive. However, there is a double edge sword here as diabetes control also affects sperm quality, discontinuing metformin treatment could also affect birth outcomes.
An andrologist at Imperial College London, Dr. Channa Jayasena, found the findings surprising because metformin is a weaker medication than insulin.
“The authors cannot exclude that men on metformin had worse control of their diabetes,” said Dr. Jayasena. “So, the results are thought-provoking but inconclusive. Men with diabetes should not be dissuaded from taking metformin, but this is worth looking at more closely.”
Diabetes increasingly occurs in people of reproductive age. The insulin imbalance disease compromises sperm quality, and is associated with impaired male fertility. Some diabetes drugs may also affect male reproductive health.
The researchers of the study explained that infants were considered exposed if their fathers filled one or more diabetes drug prescriptions during the time of development of fertilizing sperm. Researchers compared the sex and frequencies of major birth defects across drugs, times of exposure, and siblings.
More details of this report from AWM:
Another expert who was not involved in the study but has interpreted its results is Professor Sheena Lewis, an expert in reproductive medicine at Queen’s University Belfast. She pointed out that the study did not differentiate between men with diabetes who are managing their condition well versus those who are managing it poorly.
“As couples wait until older before starting families, their chances of being on medication for other chronic illnesses increases. The take-home message is that men who are trying to have children should discuss all other medications with their family doctors to ensure these have no known adverse effects on male fertility,” She said.
The study was conducted by researchers at the University of Copenhagen and published in the journal JAMA Internal Medicine. The study looked at all the babies born in Denmark between 1996 and 2013.
So far, the findings have only been released to Danish media, so it is unclear whether or not these results will have any impact on how doctors prescribe the medication to their patients.
Doctors urge men to talk to their doctor before trying to produce a baby, as the medication could have an adverse effect on male fertility.