title: Acetaminophen use in pregnancy and risk of birth defects: findings from the National Birth Defects Prevention Study.
abstract: OBJECTIVE
  To investigate whether exposure during the first trimester of pregnancy to single-ingredient acetaminophen increases the risk of major birth defects.
  
  
  METHODS
  Data from the National Birth Defects Prevention Study, a population-based, case-control study, were used. Women who delivered between January 1, 1997, and December 31, 2004, and participated in the telephone interview were included. Type and timing of acetaminophen use were assigned based on maternal report. Women reporting first-trimester acetaminophen use in a combination product were excluded, resulting in a total of 11,610 children in the case group and 4,500 children in the control group for analysis.
  
  
  RESULTS
  The prevalence of first-trimester single-ingredient-acetaminophen use was common: 46.9% (n=5,440) among women in the case group and 45.8% (n=2,059) among women in the control group (P=.21). Overall, acetaminophen was not associated with an increased risk of any birth defect. Among women reporting a first-trimester infection and fever, use of acetaminophen was associated with a statistically significantly decreased odds ratio (OR) for anencephaly or craniorachischisis (adjusted OR 0.35, 95% confidence interval [CI] 0.08-0.80), encephalocele (adjusted OR 0.17, 95% CI 0.03-0.87), anotia or microtia (adjusted OR 0.25, 95% CI 0.07-0.86), cleft lip with or without cleft palate (adjusted OR 0.44, 95% CI 0.26-0.75), and gastroschisis (adjusted OR 0.41, 95% CI 0.18-0.94).
  
  
  CONCLUSIONS
  Single-ingredient-acetaminophen use during the first trimester does not appear to increase the risk of major birth defects. It may decrease the risk of selected malformations when used for a febrile illness.
  
  
  METHODS
  II.
authors.affiliation: From the Division of Medical Genetics, Department of Pediatrics, University of Utah Health Sciences Center, Salt Lake City, Utah; the Utah Birth Defect Network, Utah Department of Health, Salt Lake City, Utah; and the North Carolina Birth Defects Monitoring Program, North Carolina Division of Public Health, Raleigh, North Carolina.
authors.forename: Marcia L
authors.initials: ML
authors.lastname: Feldkamp
authors.forename: Robert E
authors.initials: RE
authors.lastname: Meyer
authors.forename: Sergey
authors.initials: S
authors.lastname: Krikov
authors.forename: Lorenzo D
authors.initials: LD
authors.lastname: Botto
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000453:epidemiology* / Q000517:prevention & control; D000082:Acetaminophen / Q000009:adverse effects*; D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000009:adverse effects*; D005260:Female; D006801:Humans; D016017:Odds Ratio; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy / Q000453:epidemiology; D011261:Pregnancy Trimester, First; D015995:Prevalence; D014481:United States / Q000453:epidemiology
chemical_list: D018712:Analgesics, Non-Narcotic; D000082:Acetaminophen