title: Birth prevalence of congenital heart defects in Norway 1994-2009--a nationwide study.
abstract: BACKGROUND
  The reasons for decreasing birth prevalence of congenital heart defects (CHDs) in several European countries and Canada are not fully understood. We present CHD prevalence among live births, stillbirths, and terminated pregnancies in an entire nation over a period of 16 years.
  
  
  METHODS
  Information on all births in the Medical Birth Registry of Norway, 1994-2009, was updated with information on CHD from the hospitals' Patient Administrative Systems, the National Hospital's clinical database for children with heart disease, and the Cause of Death Registry. Individuals with heart defects were assigned specific cardiac phenotypes.
  
  
  RESULTS
  Among 954,413 births, 13,081 received a diagnosis of CHD (137.1 per 10,000 births, 133.2 per 10,000 live births). The prevalence per 10,000 births was as follows: heterotaxia, 1.6; conotruncal defects, 11.6; atrioventricular septal defects, 5.6; anomalous pulmonary venous return, 1.1; left outflow obstructions, 8.7; right outflow obstructions, 5.6; septal defects, 65.5; isolated patent ductus arteriosus, 24.6; and other specified or unspecified CHD, 12.7. Excluding preterm patent ductus arteriosus, the CHD prevalence was 123.4 per 10,000; per year, the prevalence increased with 3.5% (95% CI 2.5-4.4) in 1994-2005 and declined with 9.8% (-16.7 to -2.4) from 2005 onwards. Severe CHD prevalence was 30.7 per 10,000; per-year increase was 2.3% (1.1-3.5) in 1994-2004, and per-year decrease was 3.4% (-6.6 to -0.0) in 2004-2009. Numbers included severe CHD in stillbirths and terminated pregnancies.
  
  
  CONCLUSIONS
  The birth prevalence of CHD declined from around 2005. Specifically, the prevalence of severe CHD was reduced by 3.4% per year from 2004 through 2009.
authors.affiliation: Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway; Department of Heart Disease, Haukeland University Hospital, Bergen, Norway. Electronic address: elisabeth.leirgul@uib.no.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Leirgul
authors.affiliation: Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Fomina
authors.affiliation: Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway; Department of Pediatrics, Haukeland University Hospital, Bergen, Norway.
authors.forename: Kristoffer
authors.initials: K
authors.lastname: Brodwall
authors.affiliation: Department of Heart Disease, Haukeland University Hospital, Bergen, Norway; Department of Medical Science, University of Bergen, Bergen, Norway.
authors.forename: Gottfried
authors.initials: G
authors.lastname: Greve
authors.affiliation: Department of Pediatrics, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: Henrik
authors.initials: H
authors.lastname: Holmstrøm
authors.affiliation: Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway; Division of epidemiology, Norwegian Institute of Public Health, Bergen, Norway.
authors.forename: Stein Emil
authors.initials: SE
authors.lastname: Vollset
authors.affiliation: Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway; Division of epidemiology, Norwegian Institute of Public Health, Bergen, Norway.
authors.forename: Grethe S
authors.initials: GS
authors.lastname: Tell
authors.affiliation: Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway; Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway.
authors.forename: Nina
authors.initials: N
authors.lastname: Øyen
mesh_terms: D001719:Birth Certificates; D005260:Female; D006330:Heart Defects, Congenital / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009664:Norway / Q000453:epidemiology; D011247:Pregnancy; D015995:Prevalence; D012042:Registries