Complete congenital heart block: risk of occurrence and therapeutic approach to prevention.

A retrospective literature review revealed that in 41% of cases of complete congenital heart block (CCHB) there was at least one other affected sibling, emphasizing the considerable risk of carrying a second affected fetus with CCHB. Therefore an aggressive approach was taken to prevent CCHB in a fetus with a high risk for the condition as defined by (1) presence of DR3 and high titers of antibodies to SSA(Ro) and SSB(La) in the mother (2) previous history of CCHB in a sibling. In a feasibility study, thrice weekly plasmapheresis was initiated in the 19th week of gestation to remove antibodies from the maternal circulation in advance of major placental transport to the developing fetus. Prednisone was also administered to decrease antibody synthesis. The concentration of total maternal IgG and antibodies to SSA(Ro) and SSB(La) were decreased by greater than 60% during the course of therapy. Planned delivery of a healthy baby was done at 36 weeks.