Sex, birth order, and maternal age characteristics of infants with congenital heart defects.

The records of the New England Regional Infant Cardiac Program, a service program covering all of New England, provide a useful source of information about the characteristics of children born with congenital heart defects. Data were analyzed on more than 2000 children born in New England who were diagnosed with a congenital heart defect before the first birthday. Children with arterio-venous fistula, aortic stenosis, transposition of the great arteries or hypoplastic left ventricle were predominantly male; children with persistent ductus arteriosus and endocardial cushion defect were predominantly female. Positive trends in risk with increasing birth order were present for pulmonic stenosis and transposition of the great arteries, and a negative trend was seen for persistent ductus arteriosus. What evidence there was for associations with maternal age was greatly reduced after controlling for confounding by birth order.