The presence of maternal autoantibodies to SS-A/Ro and/or SS-B/La is associated with the development of fetal heart block. There are data suggesting that maternal treatment with steroids might reverse heart block. We report on a pregnancy in a mother with secondary Sjögren syndrome and systemic lupus erythematosus with presence of autoantibodies to SS-A/Ro and SS-B/La, which was complicated by the development of incomplete fetal heart block. Oral dexamethasone treatment could not prevent progression to complete heart block and was associated with a number of complications.A review of the literature revealed 19 studies (including ours) in which 93 cases of fetal heart block were treated with maternal steroid therapy. Complete heart block proved irreversible in all cases; and of 13 fetuses with incomplete heart block which received maternal steroid therapy, three had a reduction in their degree of block and one reverted to sinus rhythm. Maternal steroid therapy, initiated early in pregnancy and potentially preventing the onset of heart block, did not decrease the incidence of heart block in nine studies with 43 cases. Furthermore, the literature review revealed numerous serious side effects of maternal steroid administration during pregnancy. Data on these potential side effects are lacking in the 28 studies discussed in this review. Maternal dexamethasone therapy to prevent or treat fetal heart block remains, in our opinion, a questionable intervention and can as yet not be recommended in the clinical situation.