Controversies in the Management of Isolated Congenital Atrioventricular Block

Congenital atrioventricular block (CAVB) affects approximately 2% of fetuses of mothers with anti-Ro or anti-La antibodies, regardless of maternal rheumatologic symptoms. Anti-Ro and anti-La antibodies are antinuclear antibodies commonly found in autoimmune diseases. Congenital atrioventricular block is associated with a relatively high fetal morbidity and mortality, particularly more advanced degrees of block. There is significant controversy surrounding surveillance of anti-Ro/La-positive pregnancies and treatment of fetuses diagnosed with CAVB. Studies of dexamethasone in the treatment of CAVB have yielded conflicting results, with most suggesting only a limited potential benefit in first- and seconddegree CAVB and in cases complicated by fetal hydrops. Larger prospective studies are needed to further evaluate the efficacy of intravenous immunoglobulin in the treatment of CAVB and of intravenous immunoglobulin and hydroxychloroquine in the prevention of CAVB in fetuses of at-risk mothers. Surveillance and treatment regimens should be determined on a case-by-case basis, taking into consideration the degree of CAVB, costs, and potential adverse effects of treatment.