title: Maternal hypothyroidism may be associated with CHD in offspring.
abstract: OBJECTIVE
  This study tested whether mothers with maternal hypothyroidism have increased odds of CHD in their offspring, and examined the relationship between CHD, maternal thyroid function, and nausea and vomiting in pregnancy.
  
  
  BACKGROUND
  Maternal hypothyroidism increases the risk for foetal demise and prematurity and can have a negative impact on neurodevelopment. Prior studies have postulated a relationship between maternal thyroid function, CHD, and maternal nausea and vomiting in pregnancy.
  
  
  METHODS
  A cross-sectional case-control study was conducted over a 17-month period to obtain a history of maternal thyroid status and nausea and vomiting in pregnancy. Paediatric echocardiograms were evaluated for CHD by a blinded paediatric cardiologist. Logistic regression analysis was performed to examine the association between CHD and maternal hypothyroidism.
  
  
  RESULTS
  Of the 998 maternal-child pairs, 10% (98/998) of the mothers reported a history of prenatal hypothyroidism. The overall prevalence of CHD in the study sample was 63% (630/998). Mothers with a history of hypothyroidism were significantly more likely to have offspring with CHD compared with mothers without a history of hypothyroidism (72 versus 62%; p=0.04). The adjusted odds ratio (95% confidence interval) of CHD in offspring associated with reported maternal hypothyroidism was 1.68 (1.02-2.78).
  
  
  CONCLUSIONS
  This study suggests that maternal hypothyroidism is a risk factor for the development of CHD. Further prospective investigations are necessary to confirm this association and delineate pathogenic mechanisms.
authors.affiliation: 1Division of Cardiology,Department of Paediatrics, Faculty of Medicine & Dentistry,University of Alberta,Edmonton,Alberta,Canada.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Grattan
authors.affiliation: 2Department of Pediatrics, Faculty of Medicine & Dentistry,University of Alberta,Edmonton,Alberta,Canada.
authors.forename: Daina S
authors.initials: DS
authors.lastname: Thomas
authors.affiliation: 1Division of Cardiology,Department of Paediatrics, Faculty of Medicine & Dentistry,University of Alberta,Edmonton,Alberta,Canada.
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Hornberger
authors.affiliation: 3Department of Paediatrics,Hospital for Sick Children,Canada and University of Toronto,Toronto,Ontario,Canada.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Hamilton
authors.affiliation: 4Faculty of Medicine,Memorial University of Newfoundland,St. John's,Newfoundland,Canada.
authors.forename: William K
authors.initials: WK
authors.lastname: Midodzi
authors.affiliation: 2Department of Pediatrics, Faculty of Medicine & Dentistry,University of Alberta,Edmonton,Alberta,Canada.
authors.forename: Sunita
authors.initials: S
authors.lastname: Vohra
mesh_terms: D000293:Adolescent; D000328:Adult; D002170:Canada; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004452:Echocardiography; D005260:Female; D006330:Heart Defects, Congenital / Q000453:epidemiology* / Q000209:etiology*; D006801:Humans; D007037:Hypothyroidism / Q000175:diagnosis*; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D009035:Mothers; D009325:Nausea; D016017:Odds Ratio; D011247:Pregnancy; D011248:Pregnancy Complications; D012189:Retrospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014839:Vomiting
keywords: CHD; maternal hypothyroidism; nausea and vomiting in pregnancy