In utero identification and therapy of congenital heart block.

To determine the feasibility and effectiveness of prenatal therapy of congenital heart block (CHB), information was sought regarding the timing of identification of CHB in 72 pregnancies and the outcome of those pregnancies in which the mothers were administered corticosteroids. Mailed questionnaires with telephone follow-up, data from primary physicians and chart review were utilized. In 38 (53%) of affected pregnancies CHB was identified between 16 and 24 weeks of gestation, in 17 (24%) between 25 and 30 weeks of gestation, in 8 (11%) between 31 and 37 weeks, and in 5 (7%) between 38 and 40 weeks. In four pregnancies the timing was unknown. Five women were taking prednisone for disease activity prior to the discovery of CHB and in six other women prednisone therapy was initiated at or about the time CHB was identified. In 19 pregnancies, women were given fluorinated steroids (available to the fetus in an active form) as attempted therapy after the discovery of CHB. Of these, one fetus with second degree block reverted to sinus rhythm and two with third degree block exhibited an improvement in the degree of block. In eight fetuses pleural and/or pericardial effusions resolved. In conclusion, the gestational period of heightened fetal vulnerability for the development of heart block is in the mid second to early third trimester. Although there is no evidence that maternal prednisone should be used prophylactially, fluorinated steroids may be efficacious after the identification of heart block, particularly with regard to an associated myocarditis.

Relationship between maternal and neonatal levels of antibodies to 48 kDa SSB(La), 52 kDa SSA(Ro), and 60 kDa SSA(Ro) in pregnancies complicated by congenital heart block.

OBJECTIVE: Since there is suggestive but, to date, indirect evidence that maternal anti-SSA(Ro) and SSB(La) antibodies are pathogenic in congenital heart block (CHB), we explored the hypothesis that binding to fetal tissues would result in selective depletion of autoantibodies from the neonatal circulation. METHODS: Maternal and umbilical cord levels of anti-48 kDa SSB(La), anti-52 kDa SSA(Ro) and anti-60 kDa SSA(Ro) antibodies were measured by ELISA and immunoprecipitation at parturition in 15 pregnancies complicated by CHB. A control group consisted of 13 pregnancies in which the mother was known to have antibodies to either SSA(Ro) and/or SSB(La) and the children did not have CHB. RESULTS: The ratios of maternal to cord serum levels of anti-48 SSB(La), anti-52 SSA(Ro) and anti-60 kDa SSA(Ro) antibodies ranged from 0.71 to 2.38 in both affected and unaffected pregnancies. The mean ratio obtained for each of the 3 autoantibodies was not significantly different between the 2 groups. Moreover these ratios did not significantly differ from the mean ratios obtained for total IgG levels in either group. CONCLUSION: These data demonstrate that maternal antibodies to all components of the SSA(Ro) SSB(La) system are efficiently transported across the placenta and are not selectively depleted in the circulation of neonates with CHB.

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.