Prenatal exposure to acetaminophen and asthma in children

Obstet Gynecol. 2009 Dec;114(6):1295-1306. doi: 10.1097/AOG.0b013e3181c225c0.


Objective: To estimate whether prenatal exposure to acetaminophen is associated with risk of diagnosed asthma and asthma symptoms in children.

Methods: The authors prospectively followed 1,505 pregnant women and their children until 6 years (+/-3 months) of life. Acetaminophen use in the first and third trimesters of pregnancy was assessed before 24 weeks of gestation and within 1 month of delivery, and asthma in children was assessed when the child was 6 years old. Adjusted odds ratios (aORs) were derived from logistic regression models controlling for potential confounders.

Results: Acetaminophen was used by 69% of women during pregnancy. Use of acetaminophen did not significantly increase the risk of asthma (aOR 0.76, 95% confidence interval [CI] 0.53-1.10). Acetaminophen use during both the first and the third trimester was associated with a significantly reduced risk of asthma (aOR 0.59, 95% CI 0.36-0.98). There was no evidence of a dose response, and consumption greater than 10,400 mg (32 tablets) a month did not increase risk (aOR 0.99, 95% CI 0.19-5.30).

Conclusion: Our results suggest that acetaminophen use during pregnancy does not increase risk of asthma in children.

Level of evidence: II.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Acetaminophen / adverse effects*
  • Adult
  • Analgesics, Non-Narcotic / adverse effects*
  • Asthma / chemically induced*
  • Child
  • Female
  • Humans
  • Pregnancy
  • Prenatal Exposure Delayed Effects*
  • Prospective Studies
  • Young Adult


  • Analgesics, Non-Narcotic
  • Acetaminophen