Epidemiology, etiology and clinical associations of congenital heart disease identified during congenital rubella syndrome surveillance.

Background: Congenital heart disease (CHD) is a common congenital malformation. Antenatal rubella infection in the mother and genetic defects are important causes to which CHD are attributed. Exact contribution of antenatal rubella infection or genetic causes to CHD is still unknown.

Objective: To study the epidemiology, etiology and clinical associations of echocardiographically confirmed congenital heart disease in infants in Western Rajasthan enrolled in the congenital rubella syndrome (CRS) surveillance project. To study the utility of clinical diagnostic criteria in identifying congenital rubella infection.

Method: This was a prospective observational study, in which 251 patients with echocardiographically confirmed CHD were enrolled. Detailed clinical evaluation was done in all patients. Rubella serology was done in all patients. Genetic and other testing was done as appropriate.

Result: The hospital-based prevalence of CHD in infants was 1% at our center. Fifty-seven percent of the babies had acyanotic septal heart defects of which ventricular septal defect (VSD) was the most common (35%). Anti-rubella immunoglobulin M (IgM) antibodies were positive in 8.5% of the CHD patients. A clinically identifiable genetic cause was present in 3.6% of the cases. In patients who tested positive for anti-rubella IgM antibodies also, VSD was the most common (33%) CHD followed by Tetralogy of Fallot (13.2%).

Conclusion: CRS contributes to 8.5% of CHD. CRS is associated with a wide spectrum of CHD. The etiology of a large number of CHD remains elusive. Detailed studies on the cause and mechanism of development of CHD need to be undertaken.