Acetaminophen use during pregnancy: effects on risk for congenital abnormalities

Am J Obstet Gynecol. 2008 Feb;198(2):178.e1-7. doi: 10.1016/j.ajog.2007.08.040.


Objective: We evaluated if acetaminophen, one of the most frequently used drugs among pregnant women is associated with an increased prevalence of congenital abnormalities.

Study design: We selected 88,142 pregnant women and their liveborn singletons from the Danish National Birth Cohort who had information on acetaminophen use during the first trimester of pregnancy. We used the National Hospital Registry to identify 3784 (4.3%) children from the cohort diagnosed with 5847 congenital abnormalities.

Results: Children exposed to acetaminophen during the first trimester of pregnancy (n = 26,424) did not have an increased prevalence of congenital abnormalities (hazard ratio = 1.01, 0.93-1.08) compared with nonexposed children (n = 61,718). No association was found between congenital abnormalities and duration of use during the first trimester. Increased prevalence was not observed for specific abnormalities, except for "medial cysts, fistula, sinus" (congenital abnormalities of the ear, face, and neck, ICD-10 code Q18.8, n = 43) with an adjusted hazard ratio of 2.15 (1.17-3.95).

Conclusion: Acetaminophen is not associated with an increased prevalence of congenital abnormalities overall or with any specific group of major abnormalities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abnormalities, Drug-Induced / epidemiology*
  • Abnormalities, Drug-Induced / etiology
  • Abnormalities, Drug-Induced / pathology
  • Acetaminophen / administration & dosage
  • Acetaminophen / adverse effects*
  • Analgesics, Non-Narcotic / administration & dosage
  • Analgesics, Non-Narcotic / adverse effects*
  • Cohort Studies
  • Denmark / epidemiology
  • Female
  • Humans
  • Pregnancy
  • Pregnancy Trimester, First
  • Prevalence
  • Proportional Hazards Models
  • Prospective Studies
  • Registries
  • Risk Factors


  • Analgesics, Non-Narcotic
  • Acetaminophen