Prenatal Paracetamol Linked to Ovarian Changes

A study found links between prenatal paracetamol exposure and changes in female infant reproductive development.

Updated on Sept. 20, 2026 in Pregnancy

Bold flat-color editorial illustration in navy, cream, and red, featuring a minimalist geometric form representing biological development. — A new study links prenatal exposure to paracetamol with reduced ovarian and uterine development in female infants, raising public health questions. AI Illustration. Upload story photo >

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Is now a good time to reconsider using over-the-counter pain medication during pregnancy?

Research published on September 20, 2026, revealed that female infants exposed to paracetamol in utero exhibited smaller ovaries and reduced uterine size. The study highlights potential developmental implications for girls exposed to the common pain reliever during pregnancy.

Why it matters

With up to 65% of U.S. women reporting paracetamol use during pregnancy, understanding its impact on fetal development is a public health priority. The findings mirror previous animal studies that linked prenatal exposure to diminished ovarian reserves and fewer eggs.

The study tracked 685 pregnant women in Denmark and examined 302 infant girls at 3 months of age to assess reproductive development. Researchers confirmed that up to 65% of U.S. women report using paracetamol during their pregnancy.

The players

Food and Drug Administration

The agency issued a formal notice to physicians regarding the use of acetaminophen during pregnancy.

Janssen

A pharmaceutical company whose epidemiologist identified early connections between the drug and reproductive development.

The details

Researchers monitored exposure by collecting bi-weekly usage reports and urine samples from pregnant participants throughout the study. Clinical assessments performed when the infants reached three months of age showed they had smaller ovaries and fewer ovarian follicles compared to unexposed counterparts.

In 2018, a Janssen epidemiologist noted evidence of potential connections.
In September 2025, the DCNF reported on Janssen's private internal acknowledgments.
On September 22, 2025, the FDA issued a notice to physicians about acetaminophen use.
On September 20, 2026, the study on reproductive organ development was published.

Culture Shift

This research follows the pattern set by the FDA's September 2025 notice regarding acetaminophen use during pregnancy. It marks a departure from traditional assumptions of pregnancy-related medication safety by providing new clinical evidence of developmental impacts.

This study may prompt expecting mothers to consult with their physicians regarding pain management alternatives during pregnancy. It underscores the importance of discussing medication use with healthcare providers given the high prevalence of paracetamol use among U.S. women.

The takeaway

Patients should always consult with their primary obstetrician before making changes to their medication regimen during pregnancy. This study emphasizes that common over-the-counter drugs can have complex, long-term implications that require professional medical oversight.

What happens next

Researchers are expected to conduct larger studies with extended follow-up to determine the long-term clinical relevance of these ovarian and uterine findings.