Metformin is a commonly used first-line drug for the treatment of type 2 diabetes. A study now conducted at Stanford Medicine (USA) together with Danish researchers has found that its use by the father three months before Conception could affect sperm development in such a way as to triple the risk of genital birth defects in male offspring.
And it is that, paternal factors are key in the correct development of babies, and although much is known about those of the mother, such as there is a list of medications that should not be taken during pregnancy, not many studies have been done to investigate the role of the father in the health of the little ones.
In this work, which has been published in the journal Annals of Internal Medicine, they focused on data from more than one million births in Denmark and related the health of babies to the drugs their parents were taking three months before conception, specifically metformin, insulin, or sulfonylureas, all intended to treat diabetes by lowering blood sugar levels and increasing insulin sensitivity.
The results showed that babies of parents taking insulin did not have an increased risk of birth defects, compared to the general group, and not enough data was collected to draw any conclusions from those on sulfonylureas. However, this was observed in those neonates whose parents took metformin, although it only occurred in male offspring.
5.2% rate of birth defects for metformin
The researchers found that the 1,451 children of parents who took metformin three months before conception had a birth defect rate of 5.2%, compared to 3.3% for those whose parents did not take the drug. . This is a 1.4-fold increase in the odds of major birth defects, such as genital, urinary, digestive, and heart defects.
Metformin could affect the proper development of semen, interfering with sperm maturation, which would cause birth defects
Although the rate of genital defects, such as hypospadias – the urethra does not exit through the tip of the penis – was low, specifically 0.9% of all babies born to parents who took metformin in the three months before pregnancy, Epidemiologists consider it important, since tens of millions of people in the world take this drug to treat mainly type 2 diabetes.
The possible explanation that the authors are considering is that metformin somehow affects semen production, which seems to be produced for three months until the sperm fully mature. “It wasn’t just taking metformin at any point in a man’s life, it really has to do with taking it at that window when the sperm that will become the child is developing,” said Michael Eisenberg, lead author of the study.
To verify their results, the researchers tested in mice, and found that those pregnant rodents that took metformin had male offspring with smaller testicles, which may indicate that the drug can cause reproductive damage. Although the results are striking, the authors urge caution and continue research, even so, they believe that if you are thinking of becoming a father, you should seek guidance from doctors when planning pregnancy in order to weigh the risks and benefits of parental use of metformin in relation to other alternative medications.
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