Congenital heart block (CHB), detected at or before birth in a structurally normal heart, is strongly associated with autoantibodies reactive with the intracellular soluble ribonucleoproteins 48kD SSB/La, 52kD SSA/Ro, and 60kD SSA/Ro.
Although a strong clinical association exists between congenital heart block (CHB) and an immune response to SSA/Ro and SSB/La proteins, a causative role of these antibodies in the pathogenesis is just emerging.
Congenital heart block (CHB), associated with antibodies to SS-A/Ro and SS-B/La, is most often detected between 18 and 24 weeks of gestation, yet the maternal heart is unaffected.
This study indicates that placental transfer of anti-Ro(SSA) or anti-La(SSB) alone to the fetus is not sufficient for the expression of congenital complete heart block.