Prevalence of Congenital Heart Defects in Metropolitan Atlanta, 1998–2005

Abstract

Congenital heart defects (CHD) are the leading cause of infant mortality, and are associated with chronic disability and morbidity in survivors. Most estimates of CHD prevalence are based on data from population-based birth defects surveillance systems. Considerable variability in the incidence of CHD was reported by a review of 44 international studies. Much of the variability appeared to be due to differences in the ascertainment of minor CHDs and the lack of a standardized classification system and nomenclature in prevalence studies. To derive an accurate estimate of the prevalence of CHD, this population-based study used a standardized cardiac nomenclature and classification system, the International Pediatric and Congenital Cardiac Code developed by members of the Society of Thoracic Surgeons and the European Association of Cardio-thoracic Surgery, to assess selected characteristics among infants with CHD identified in the Metropolitan Atlanta Congenital Defects Program (MACDP) from 1998 to 2005. The prevalence of CHD per 10,000 live births in the overall birth cohort was estimated. Infants with transient conditions such as patent ductus arteriosis that resolved in <6 weeks were excluded. Of the 398,140 live births in the cohort, 3240 had a CHD, for an overall prevalence of 81 infants/10,000 births. The most prevalent defects, comprising more than half of the total, were left-to-right shunt lesions. Of these, the most common defect was muscular ventricular septal defect, with a prevalence of 27.5/10,000 births. It occurred more than twice as often as the next two most common cardiac defects, perimembranous ventricular septal defect and secundum atrial septal defect, which occurred at a prevalence of 10.3 and 10.6/10,000 births, respectively. Other left-to-right-shunts found less frequently were atrial-ventricular septal defect and patent ductus arteriosus, with a prevalence of 4.1 and 2.9 /10,000 births, respectively. Among the cyanotic congenital heart defects, tetralogy of Fallot TOF was the most common, occurring in twice as many infants as transposition of the great arteries (4.7/10,000 births versus 2.3/10,000 births, respectively). Some CHD were associated with low gestational age and birthweight, older maternal age, multiple-gestation pregnancies, and infant gender. The investigators believe that current prevalence estimates of the various CHD subtypes provided in this study using standardized nomenclature and a well-documented classification system subtypes may be a benchmark for future studies.