Pregnancy Tylenol Use Linked to Infant Reproductive Changes

A study published on September 6, 2026, has indicated that a mother's use of Tylenol during pregnancy may impact the reproductive organ development of infant girls. Researchers found that babies exposed to Tylenol in utero, on average, had smaller ovaries, fewer ovarian follicles, and smaller uteruses compared to those not exposed.

Infants exposed to Tylenol before 17 weeks of pregnancy also showed lower levels of Anti-Müllerian hormone, a key indicator of ovarian reserve. While animal studies have suggested such effects, this is the first report of similar findings in humans. The study's lead author stressed that the findings do not prove Tylenol's direct causality nor indicate future fertility issues.

Experts suggest further long-term follow-up into menopause is necessary. Current guidelines still recommend Tylenol as safe for pain and fever during pregnancy, noting that untreated maternal fever or pain can pose risks. The study's findings, published in Human Reproduction Open, do not predict outcomes for individual children.