Prenatal Paracetamol Exposure Linked to Smaller Ovaries

Key Points

• Prenatal paracetamol exposure was associated with a 40% smaller ovarian volume, 13% smaller uterine volume, and 23% fewer ovarian follicles in three-month-old girls.
• Early fetal exposure was also linked to lower anti-Müllerian hormone (AMH) levels, a marker of ovarian reserve.
• An independent cohort found associations with smaller ovaries during adolescence and smaller uteruses at puberty.
• The study was observational and does not prove that paracetamol causes reproductive problems or infertility.
• Researchers recommend long-term follow-up into adulthood and menopause to determine whether these early differences have clinical significance.
• For More Updates in Women’s Health and Gynecology, register for the HerHealth2026 CME Conference

What does prenatal paracetamol exposure mean for ovarian development?

Prenatal paracetamol exposure may be associated with measurable differences in reproductive development, according to findings from the Copenhagen Analgesic Study (COPANA), published in Human Reproduction Open.

Researchers followed pregnant women and assessed 302 of their daughters at three months of age. They compared girls exposed to paracetamol during fetal life with those without reported exposure.

Among exposed infants, researchers observed an average 40% smaller ovarian volume, 13% smaller uterine volume, and 23% fewer ovarian follicles. Girls exposed during early fetal life also had lower concentrations of anti-Müllerian hormone (AMH), an established marker of ovarian reserve.

The findings address an important question in reproductive medicine and gynecology because the ovarian follicle pool forms during fetal development and gradually declines throughout life.

How might paracetamol exposure affect female reproductive development?

The findings align with previous animal research suggesting that paracetamol exposure during pregnancy could interfere with fetal ovarian development and follicle formation. However, researchers emphasize that the human study only identified associations.

The team also examined 1,210 girls from an independent Copenhagen Mother-Child Cohort. In this group, prenatal paracetamol exposure was associated with smaller uteruses at puberty and smaller ovaries during adolescence, providing additional support for the observed relationship.

The study population generally received relatively low paracetamol exposure, and none of the mothers exceeded the recommended maximum daily dose of 4,000 mg.

What should healthcare professionals know about paracetamol use during pregnancy?

The researchers caution against interpreting the findings as evidence that paracetamol causes infertility or earlier menopause. The study did not assess reproductive outcomes in adulthood, and researchers need long-term follow-up through reproductive age and menopause to determine whether the observed anatomical and hormonal differences have clinical significance.

For More Updates in Women’s Health and Gynecology, register for the HerHealth2026 CME Conference

For HCPs and nurses, the findings reinforce the importance of individualized medication counseling during pregnancy. Current European and UK guidance continues to recommend paracetamol as a first-choice treatment for pain and fever during pregnancy when clinically indicated. Untreated fever or severe pain can also present risks to the mother and fetus.

Non-pharmacological measures, including rest, hydration, physiotherapy, exercise, and heat therapy, may help manage some conditions when clinically appropriate.

Further research should clarify whether prenatal paracetamol exposure, ovarian reserve, fertility, and reproductive aging are causally connected.

Source:

European Society of Human Reproduction and Embryology