Recurrence rates of cardiac manifestations associated with neonatal lupus and maternal/fetal risk factors

OBJECTIVE: Identifying the frequency of recurrent cardiac manifestations of neonatal lupus (NL) in a second child is critical to understanding the pathogenesis of anti-SSA/Ro-mediated injury and would improve counseling strategies regarding future pregnancies and power the design of clinical prevention trials. Accordingly, this study was undertaken to address the recurrence rates of cardiac NL and associated risk factors in a large US-based cohort. METHODS: Families enrolled in the Research Registry for Neonatal Lupus were evaluated for rates of recurrence of cardiac NL and potential risk factors, with a focus on pregnancies immediately following the birth of an affected child. RESULTS: The overall rate of recurrence of cardiac NL in 161 pregnancies of 129 mothers with anti-SSA/Ro antibodies was 17.4% (95% confidence interval 11.1-23.6%). Analysis of the potential risk factors among 129 mothers with a pregnancy immediately following the birth of a child with cardiac NL showed that the maternal diagnosis was not associated with the outcome in a subsequent pregnancy. In this group, 23% of mothers who were either asymptomatic or had an undifferentiated autoimmune syndrome, compared with 14% of mothers with systemic lupus erythematosus or Sjögren's syndrome, had a second child with cardiac NL (P = 0.25). The recurrence rate was not statistically significantly different in mothers who had taken steroids compared with those who had not taken steroids (16% versus 21%; P = 0.78). The antibody status of the mother was not predictive of outcome in subsequent pregnancies. Moreover, death of the first child with cardiac NL was not predictive of recurrence of cardiac NL in a subsequent pregnancy (P = 0.31). The risk of cardiac NL was similar between male and female children (17.2% versus 18.3%; P = 1.0). CONCLUSION: In this cohort, the overall recurrence rate for cardiac NL was 17%. The recurrence rate appeared to be unaffected by maternal health, use of steroids, antibody status, severity of cardiac disease in the first affected child, or sex of the subsequent child.