Danish study links maternal paracetamol use to smaller reproductive organs in newborn girls
An observational cohort of 302 Danish newborn girls found that maternal intake of paracetamol during pregnancy was associated with reduced ovarian and uterine size and fewer antral follicles, though the exact magnitude of the effect was not disclosed in the source.
A Danish observational cohort of 302 newborn girls has reported associations between maternal paracetamol intake during pregnancy and reduced size of the daughters’ ovaries and uterus, as well as a lower count of antral follicles. The findings were described in the journal Human Reproduction Open and summarised by the German newspaper Handelsblatt on 2026‑09‑09.
Study design and sample
The research team, led by a scientist named Fischer, analysed data from 685 women who reported medication use in the first trimester of pregnancy. After delivery, 302 daughters were examined at a median age of 106 days – roughly three months – to assess reproductive‑organ size and hormone levels. The study is observational, meaning it can identify correlations but cannot prove causality.
| Metric | Value |
|---|---|
| Number of mothers analysed | 685 |
| Number of daughters examined | 302 |
| Median age at examination | 106 days (≈3 months) |
Source: Handelsblatt, 2026‑09‑09.
Reported associations
According to the Handelsblatt summary, girls whose mothers took paracetamol before week 17 of gestation displayed smaller ovarian and uterine volumes when examined at three months of age. A separate subgroup of girls whose mothers used the drug after week 17 showed a lower number of antral follicles. The newspaper quotes the study authors as stating that the early‑exposure group also had lower levels of anti‑Müllerian hormone (AMH), a marker of ovarian reserve.
The article does not provide the exact percentage reductions for ovarian volume, uterine volume, or follicle count. While the research packet lists figures of “around 40 % lower ovarian volume, 13 % lower uterine volume and 23 % fewer follicles,” those numbers are not present in the Handelsblatt source and therefore cannot be presented as verified facts.
Context and comparable evidence
The same research team also examined a separate cohort of 1 210 girls from an earlier study. In that group, maternal paracetamol use was linked to smaller uterine size in puberty and reduced ovarian volume in adolescence. Those observations echo animal‑study findings that suggest paracetamol can interfere with reproductive development, but the human data remain limited to associations.
Other epidemiological work has explored the relationship between analgesic use in pregnancy and later reproductive outcomes, but results have been mixed and often lack the granularity needed to assess dose‑response or timing effects. The Danish cohort adds a focus on very early post‑natal measurements, which is relatively rare in the literature.
Limitations and unanswered questions
Because the study is observational, confounding factors such as underlying maternal health conditions, concurrent medication use, or lifestyle variables could influence the reported associations. The source does not disclose how paracetamol exposure was measured (self‑report, prescription records, etc.), nor does it provide information on dosage or frequency.
Crucially, the precise magnitude of the reported reductions – the 40 %, 13 % and 23 % figures cited in some secondary reports – cannot be confirmed from the primary source available to us. Without the original journal article, readers cannot assess the statistical significance, confidence intervals, or adjustment for potential confounders.
Implications for public health
Paracetamol (acetaminophen) is the most widely used analgesic in pregnancy, and the potential for long‑term reproductive effects raises concerns for clinicians and expectant mothers. The Danish findings suggest that timing of exposure may matter, but the evidence is not yet strong enough to change clinical guidelines. Health authorities typically advise that paracetamol be used at the lowest effective dose for the shortest necessary period, a recommendation that remains prudent in light of these new, albeit preliminary, observations.
Further research – ideally with larger sample sizes, detailed dosage data, and longer follow‑up into adolescence – will be needed to clarify whether the observed associations translate into clinically meaningful outcomes such as reduced fertility or altered timing of menopause.
What remains unknown
- The exact quantitative effect sizes for ovarian volume, uterine volume and antral follicle count.
- Whether the associations persist into later childhood, adolescence or adulthood.
- The role of dosage, formulation (e.g., combination products) and frequency of paracetamol use.
- Potential mechanisms linking early‑gestation exposure to reproductive‑organ development.
Until the primary journal article is examined, the central claim that maternal paracetamol intake reduces ovarian volume by 40 % and uterine volume by 13 % cannot be verified.