Prevention and treatment in utero of autoimmune-associated congenital heart block.

Transplacental transfer of maternal anti-Ro and/or anti-La autoantibodies can result in fetal cardiac disease, including congenital heart block and cardiomyopathy, called cardiac neonatal lupus (NL). Thousands of women are faced with the risk of cardiac NL in their offspring, which is associated with significant morbidity and mortality. There are no known therapies to permanently reverse third-degree heart block in NL, although several treatments have shown some effectiveness in incomplete heart block and disease beyond the atrioventricular node. Fluorinated steroids taken during pregnancy have shown benefit in these situations, although adverse effects may be concerning. Published data are discordant on the efficacy of fluorinated steroids in the prevention of mortality in cardiac NL. β-agonists have been used to increase fetal heart rates in utero. The endurance of β-agonist effect and its impact on mortality are in question, but when used in combination with other therapies, they may provide benefit. No controlled experiments regarding the use of plasmapheresis in cardiac NL have been performed, despite its theoretical benefits. Intravenous immunoglobulin was not shown to prevent cardiac NL at a dose of 400 mg/kg, although it has shown effectiveness in the treatment of associated cardiomyopathy both in utero and after birth. Retrospective studies have shown that hydroxychloroquine may prevent the recurrence of cardiac NL in families with a previously affected child, and a prospective open-label trial is currently recruiting patients in order to fully evaluate this relationship.