Maternal Anti-Ro/SSA and Anti-La/SSB Antibodies and Fetal Congenital Heart Block.

The incidence of CHB is 2 % in cases of maternal anti-Ro/ SSA antibody positivity, 3 % when both anti Ro/SSA and anti-La-SSB are positive. The risk of recurrence is 9 times higher in the subsequent pregnancies [1]. Underlying structural congenital heart disease is associated with more than half of the fetuses found to have CHB and it is then defined ‘‘isolated’’ in the absence of structural heart disease. It is important to distinguish these two forms of CHB because they differ not only in their pathogenesis and in their rate of recurrence, but also in the prognoses of children affected. Infants with CHB associated with severe structural heart disease have a poorer prognosis than infants with isolated CHB [2].