Paracetamol, a painkiller commonly prescribed to pregnant women because of its presumed safety, may affect the hormones of babies in utero, according to recent research.
While paracetamol – also known as acetaminophen – has long been considered one of the safest painkillers pregnant women can take, new studies are showing that over a week of continuous usage can reduce testosterone in developing testes by up to 45 percent.
Studying The Effects
One of the most recent studies, published in the journal Science Translational Medicine, studied the development of mouse fetuses in mice given paracetamol three times daily for either 24 hours or seven days.
While the mice who were given the drug over a 24 hour period showed no ill effects, the mice that took the drug over the more extended period of time showed a 45 percent decrease in their developing testes grafts(1).
While this study is limited in that it was done only in an animal model, it is consistent with the findings of a 2010 Danish study which also linked painkiller use in pregnancy with undescended testicles in male babies(2).
The researchers on both studies feel that there is sufficient evidence to warrant more investigation into how paracetamol affects human fetuses.
Limiting Painkiller Use
While these findings make a compelling case against long-term painkiller use in pregnancy, that doesn’t necessarily mean that all painkiller use is off the table for pregnant women.
In fact, there are times when taking paracetamol may still be the best option for both mother and child.
Martin Ward-Platt, a spokesperson for the Royal College of Paediatrics and Child Health in the UK, spoke with the BBC about the study, saying:
“The study specifically relates to paracetamol use over at least several days… fever during pregnancy can be harmful to the developing embryo, with links to significant increase in the rates of spina bifida and heart malformations, so small doses of paracetamol are sometimes necessary.”(3)
Researchers are looking into what the exact recommended duration and amount is to use for pregnant women may be, in order to provide clearer regulations and guidelines for expectant mothers.
Part Of A Bigger Picture
The safey of paracetamol has been called into question on numerous levels recently. While it remains one of the safest painkillers when used in small, regulated doses, paracetamol is one of the most commonly overdosed-on medications in the UK(4).
Still, many healthcare providers rely on it as a painkiller, especially in high-risk patients who may not be able to take other prescription painkillers for a variety of reasons. In comparative study of paracetamol and other painkillers such as NSAIDs, researchers concluded that paracetamol “is a viable alternative to the NSAIDs, especially because of the low incidence of adverse effects.”(5)