Autoantibody-associated congenital heart block: outcome in mothers and children.

OBJECTIVE

To determine the initial clinical status and the long-term outcome of mothers and their children with autoantibody-associated congenital heart block.

DESIGN

Dynamic, longitudinal cohort study.

PATIENTS

55 children with isolated congenital heart block, their 52 mothers, and 5 other women currently carrying fetuses with congenital heart block. All maternal sera contained antibodies to SSA/Ro alone or to both SSA/Ro and SSB/La.

MEASUREMENTS

Clinical information obtained from mailed questionnaires, telephone interviews, primary physicians, and chart reviews.

RESULTS

When congenital heart block was identified in the children, 23 women were asymptomatic, 15 had systemic lupus erythematosus, 8 had the Sjögren syndrome, and 11 had an undifferentiated autoimmune syndrome. Follow-up ranged from 1 week to 20 years (median, 3.7 years). Eleven (48%) of the 23 initially asymptomatic mothers developed symptoms of a rheumatic disease (0.15 status changes/patient-year of follow-up; 6 (26%) developed an undifferentiated autoimmune syndrome, 2 (9%) developed the Sjögren syndrome, and 3 (13%) developed systemic lupus erythematosus. One mother with the Sjögren syndrome progressed to systemic lupus erythematosus. Four (16%) of 25 subsequent pregnancies in 22 women were complicated by heart block. Seventeen affected children died, 12 within 1 month of birth. Pacemakers were implanted in 37 (67%) of the 55 children, 27 within 3 months after birth.

CONCLUSION

The development of rheumatic disease in asymptomatic mothers identified by the birth of a child with congenital heart block is common but not universal. The risk for congenital heart block in subsequent pregnancies is low. One third of the children with autoantibody-associated congenital heart block die in the early neonatal period and, of those who survive, most require pacemakers.