title: Maternal thyroid disease, thyroid medication use, and selected birth defects in the National Birth Defects Prevention Study.
abstract: BACKGROUND
  Although thyroid disorders are present in approximately 3% of pregnant women, little is known about the association between maternal thyroid disease and birth defects.
  
  
  METHODS
  We assessed the association between maternal thyroid disease, thyroid medication use, and 38 types of birth defects among 14,067 cases and 5875 controls in the National Birth Defects Prevention Study, a multisite, population-based, case-control study. Infants in this study were born between October 1997 and December 2004. Information on exposures including maternal diseases and use of medications was collected by telephone interview.
  
  
  RESULTS
  We found statistically significant associations between maternal thyroid disease and left ventricular outflow tract obstruction heart defects (1.5; 95% CI, 1.0-2.3), hydrocephaly (2.9; 95% CI, 1.6-5.2), hypospadias (1.6; 95% CI, 1.0-2.5), and isolated anorectal atresia (2.4; 95% CI, 1.2-4.6). Estimates for the association between periconceptional use of thyroxine and specific types of birth defects were similar to estimates for any thyroid disease. Given that antithyroid medication use was rare, we could not adequately assess risks for their use for most case groups.
  
  
  CONCLUSIONS
  Our results are consistent with the positive associations between maternal thyroid disease or thyroid medication use and both hydrocephaly and hypospadias observed in some previous studies. New associations with left ventricular outflow tract obstruction heart defects and anorectal atresia may be chance findings.
authors.affiliation: Congenital Malformations Registry, New York State Department of Health, Troy, New York, USA. mlb10@health.state.ny.us
authors.forename: Marilyn L
authors.initials: ML
authors.lastname: Browne
authors.forename: Sonja A
authors.initials: SA
authors.lastname: Rasmussen
authors.forename: Adrienne T
authors.initials: AT
authors.lastname: Hoyt
authors.forename: D Kim
authors.initials: DK
authors.lastname: Waller
authors.forename: Charlotte M
authors.initials: CM
authors.lastname: Druschel
authors.forename: Alissa R
authors.initials: AR
authors.lastname: Caton
authors.forename: Mark A
authors.initials: MA
authors.lastname: Canfield
authors.forename: Angela E
authors.initials: AE
authors.lastname: Lin
authors.forename: Suzan L
authors.initials: SL
authors.lastname: Carmichael
authors.forename: Paul A
authors.initials: PA
authors.lastname: Romitti
mesh_terms: D000015:Abnormalities, Multiple / Q000453:epidemiology; D000293:Adolescent; D000328:Adult; D013956:Antithyroid Agents / Q000627:therapeutic use*; D016022:Case-Control Studies; D002648:Child; D000013:Congenital Abnormalities / Q000453:epidemiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D018811:Maternal Exposure; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology* / Q000517:prevention & control; D011297:Prenatal Exposure Delayed Effects; D013959:Thyroid Diseases / Q000150:complications* / Q000188:drug therapy
chemical_list: D013956:Antithyroid Agents