Congenital heart block and maternal systemic lupus erythematosus.

The association between infants with congenital heart block (CHB) and the presence or later development of maternal systemic lupus erythematosus or other connective-tissue disease (CTD) was reviewed in 67 cases. In 24 cases CHB was diagnosed at or before birth. Of nine necropsies on affected infants, seven showed endomyocardial fibrosis. The results suggest that one in three mothers who deliver babies with CHB have or will develop CTD. The association is probably explained by placental transfer of a maternal antibody. Awareness of the association may lead to prevention of the birth of children with CHB and better neonatal care of affected children.