Pregnant women who take the painkiller Tylenol (acetaminophen) regularly for long periods may impact their unborn sons’ testosterone levels at risk, resulting in possible reproductive disorders later in life. The study was published on May 20 in the journal Science Translational Medicine by researchers at the University of Edinburgh in Scotland.
In the United Kingdom, acetaminophen is marketed under the name paracetamol. The drug is one of the most widely-used medications to ease pain and reduce fever; it is commonly used routinely during all stages of pregnancy. For the study, the researchers used mice with grafts of human testicular tissue. The effect of paracetamol on testosterone production in mice with grafts of human testicular tissue mimicked how testes develop and function in pregnancy.
The mice received a typical daily dose of paracetamol over a period of either 24 hours or 7 days and then the amount of testosterone produced by the human tissue an hour after the final dose of paracetamol. Was measured. The investigators found that one week of paracetamol treatment resulted in a significant drop in the production of testosterone, a hormone that is essential for men’s health. Twenty-four hours of paracetamol treatment had no effect; in contrast, after seven days of exposure, the amount of testosterone decreased by 45%.
The authors noted that that reduced exposure to testosterone in the uterus has been linked to higher risk of infertility, testicular cancer, and undescended testicles. They noted that the study adds to evidence that prolonged paracetamol use in pregnancy may increase the risk of reproductive disorders in male infants. They recommended that further research should be conducted regarding how paracetamol may affect testosterone levels. In the meantime, they recommended that pregnant women should follow current guidance that the painkiller be taken at the lowest effective dose for the shortest possible time.