Congenital complete heart block and SSA antibodies: obstetric implications.

Mothers with known or occult rheumatic disorders may be delivered of infants with congenital complete heart block. The more frequent use of ultrasonography during pregnancy now allows early detection of heart block in utero. The transplacental passage of SSA or SSB antibodies, of the IgG class, may mediate or be associated with immune damage to the fetal cardiac conduction system, as reported in our two patients. Maternal and/or newborn screening for SSA and SSB antibodies in selected patients permits an early presumptive diagnosis and will assist perinatal planning, particularly for immediate newborn cardiac pacemaker implantation. Early serologic detection of such antibodies may also assist family counseling of mothers at risk and should promote investigation of techniques to modify the immune status of these mothers. SSA- or SSB-positive maternal/fetal pairs should be prospectively managed by the obstetrician, neonatologist, and rheumatologist.