Risk factors in congenital heart disease.

A case-control study was conducted to investigate the risk factors of congenital heart disease (CHD). The cases were 346 children with CHD who were admitted to a university hospital in Tehran from 1995 to 2000 and controls (n=346) were randomly selected from children without CHD who were admitted during the same period. The medical records of both cases and controls were reviewed. Ten risk factors were studied and found to be more prevalent among cases (47%) than controls (35%, p < 0.005). Extracardiac malformations (OR, 31.1; CI95, 15.9-60.9; p < 0.001) and chromosomal abnormalities (OR, 34.05; CI95, 23.3-49.8; p < 0.001) were significant risk factors for CHD. Dysmorphic syndromes (p < 0.05) and CHD in siblings (p < 0.001) were also significant risk factors. Maternal illness and drug use in the first trimester of pregnancy, maternal history of previous abortions and stillbirths, parental consanguinity, and parental cardiac lesions were not significant risk factors for CHD in offspring. Results suggest that genetic factors more than environmental or reproductive factors can increase the occurrence of cardiac defects.