National time trends in congenital heart defects, Denmark, 1977-2005
Received 22 September 2008; accepted 23 October 2008. published online 24 December 2008.
Background
Time trends in congenital heart defects (CHD) by specific phenotype and with long follow-up time are rarely available for an entire population. We present trends in national CHD prevalences over the past 3 decades.
Methods
We linked information from the National Patient Register, the Causes of Death Register, and the Danish Cytogenetic Central Register for all persons born in Denmark, 1977 to 2005, and registered in the Civil Registration System, yielding a cohort of 1,763,591 persons—18,207 with CHD. Individuals with CHDs were classified by phenotype (heterotaxia, conotruncal defect, atrioventricular septal defect, anomalous pulmonary venous return, left and right ventricular outflow tract obstructions, septal defects, complex defects, associations, patent ductus arteriosus, unspecified, and other specified) by combining International Classification of Diseases codes using a hierarchical approach.
Results
From 1977 to 2005, the overall CHD birth prevalence increased from 73 to 113 per 10,000 live births. Generally, prevalence increased for defects diagnosed in infancy, until 1996–1997, and then stabilized. For each 5-year interval, isolated septal defects and severe defects increased by 22% (95% CI, 20%-25%) and 5% (95% CI, 4%-7%), respectively. Among the severe defects, conotruncal defects and atrioventricular septal defect showed the largest prevalence increases. Women had a lower prevalence of severe defects during the 1980s. The CHD prevalence increase was unchanged when persons with extracardiac defects or chromosomal aberrations were excluded.
Conclusions
CHD birth prevalence increased from the beginning of the 1980s but stabilized in the late 1990s.
aDepartment of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
bCenter for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway
cDepartment of Public Health and Primary Healthcare, University of Bergen, Bergen, Norway
dDepartment of Clinical Genetics, Århus University Hospital, Århus, Denmark
ABSTRACT