Investigations into Ro-specific antibody-associated congenital cardiac conduction defects.

Forty-two babies with different congenital cardiac conduction defects, and in 12 cases the mothers, were tested for autoantibodies to Ro, La, U1RNP and Sm. Ro-specific antibodies were detected most frequently. They were to be found in 16 sera from infants and in 8 maternal serum samples. The occurrence of anti-Ro was associated preferentially with several atrioventricular conduction blocks. The sex relation of anti-Ro associated congenital heart block did not show a typical preference (6 male/10 female). At the time of giving birth, 5 anti-Ro-positive mothers did not have any clinical symptoms of rheumatic autoimmune diseases. Three of them had a first degree atrioventricular block. Our findings indicate that all pregnant women at risk for anti-Ro like connective tissue disease or cardiac conduction defects should be tested for these autoantibodies because of the suspicion of cardiac conduction abnormalities in the offspring. Anti-Ro-positive infants should be examined for structural heart disease by echocardiography.