title: Impact of prenatal risk factors on congenital heart disease in the current era.
abstract: BACKGROUND
  The healthcare burden related to congenital heart disease (CHD) is increasing with improving survival. We assessed changing trends in prenatal risk factors for CHD in the current era in a Canadian cohort.
  
  
  RESULTS
  CHD patients <18 years old (n=2339) and controls without structural heart disease (n=199) were prospectively enrolled in an Ontario province-wide biobank registry from 2008-2011. Family history, frequency of extra-cardiac anomalies (ECAs), and antenatal risk factors were assessed. Temporal trends were analyzed and associations with CHD were measured using linear and logistic regression. Family history of CHD and frequency of major ECAs was higher in cases versus controls (P<0.001). Despite an increase in genetic testing in the recent era, only 9.5% of cases with CHD had a confirmed genetic diagnosis. Yield of genetic testing (ie, frequency of abnormal results) was higher in familial and syndromic cases. There was an increase in parental age at conception, maternal prepregnancy body mass index, maternal urinary tract infections, type 1 diabetes, and exposure to nonfertility medications during pregnancy from 1990-2011. Later year of birth, family history of CHD, presence of major ECAs, maternal smoking during pregnancy, and maternal medication exposure were associated with increased odds of CHD (P<0.05 for all). Advanced parental age was associated with increased odds of CHD caused by genetic abnormalities.
  
  
  CONCLUSIONS
  The increase in prenatal risk factors for CHD highlights the need for more rigorous ascertainment of genetic and environmental factors including gene-environment interactions that contribute to CHD.
authors.affiliation: Division of Cardiology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Alan
authors.initials: A
authors.lastname: Fung
authors.forename: Cedric
authors.initials: C
authors.lastname: Manlhiot
authors.forename: Sapna
authors.initials: S
authors.lastname: Naik
authors.forename: Herschel
authors.initials: H
authors.lastname: Rosenberg
authors.forename: John
authors.initials: J
authors.lastname: Smythe
authors.forename: Jane
authors.initials: J
authors.lastname: Lougheed
authors.forename: Tapas
authors.initials: T
authors.lastname: Mondal
authors.forename: David
authors.initials: D
authors.lastname: Chitayat
authors.forename: Brian W
authors.initials: BW
authors.lastname: McCrindle
authors.forename: Seema
authors.initials: S
authors.lastname: Mital
mesh_terms: D005260:Female; D005820:Genetic Testing; D006330:Heart Defects, Congenital / Q000453:epidemiology* / Q000235:genetics; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011296:Prenatal Diagnosis; D011446:Prospective Studies; D012307:Risk Factors
keywords: congenital heart disease; environment; fetal cardiovascular abnormality; genetic testing; prenatal diagnosis