A study suggests that paracetamol taken during pregnancy may affect the development of girls’ ovaries and uterus

A study published in the journal Human Reproduction Open suggests that exposure to paracetamol during pregnancy could influence the development of girls’ reproductive organs. However, researchers caution that the findings do not demonstrate that the medication causes infertility.

The team from Rigshospitalet in Copenhagen analyzed 302 three-month-old girls whose mothers had been monitored for paracetamol use. Of these, 92 had been exposed to the medication before the 17th week of pregnancy, 67 after that point, and 143 had not been exposed.

On average, the exposed girls had a 40% smaller ovarian volume, a 13% smaller uterine volume, and 23% fewer ovarian follicles. Early exposure was also associated with lower levels of anti-Müllerian hormone, an indicator of ovarian reserve.

In a separate group of 1,210 girls followed until adolescence, researchers observed associations between prenatal exposure and smaller uterine and ovarian dimensions. The study is observational, meaning it cannot establish a causal relationship or predict how each child will develop.

Researchers say monitoring through adulthood is needed to determine whether the differences affect fertility or the timing of menopause. Current guidelines continue to recommend paracetamol for pain and fever during pregnancy, at the indicated doses, because untreated fever may pose risks to the mother and fetus.