A case-control study of congenital heart block: association with maternal antibodies to Ro(SS-A) and La(SS-B).

A case control study of congenital complete heart block (CHB) was undertaken to determine the degree of association of this condition with maternal connective tissue disease and with maternal autoantibodies, in particular those to Ro(SS-A). Mothers of cases (n = 18) and controls (n = 72) completed a self-administered questionnaire and donated 10 ml of blood. The odds of giving birth to a child with CHB were increased by a factor of 22 for women with antibodies to Ro(SS-A) and/or La(SS-B) compared with women who did not have these antibodies. Thus the association between CHB and both anti-Ro(SS-A) and anti-La(SS-B) antibodies has been demonstrated in an Australian population and indicates that anti-La(SS-B), as well as anti-Ro(SS-A) antibodies may be a risk factor for the development of CHB.