EDINBURGH, Scotland, May 21 (UPI) -- The main drug used during pregnancy for pain relief and fever has been found in lab tests to lower the exposure of unborn boys to testosterone.
Scientists tested the effects of paracetamol, known as acetaminophen or APAP in the U.S., by grafting human testicular tissue to mice and giving them a daily dose of the drug.
The mice showed no effect after 24 hours of receiving a typical amount of the drug. Receiving this dose regularly for 7 days, however, was shown to decrease testosterone production by nearly half.
"This study adds to existing evidence that prolonged use of paracetamol in pregnancy may increase the risk of reproductive disorders in male babies," said Dr. Rod Mitchell, a Wellcome Trust Intermediate Clinical Research Fellow at the University of Edinburgh, in a press release.
Lower exposure to testosterone in the womb can lead to an increased risk for undescended testicles, testicular cancer and infertility.
"We would advise that pregnant women should follow current guidance that the painkiller be taken at the lowest effective dose for the shortest possible time," Mitchell said.
The study is published in Science Translational Medicine.
