The predictive value of anti-SS-A antibodies titration in pregnant women with fetal congenital heart block

Objective Fetal congenital complete heart block(CHB) is irreversible and is associated with significant mortality and morbidity. Anti-SS-A antibodies in the maternal sera are involved in its pathogenesis; however, the predictive value of the antibody titerand its role in prediction of this complication are controversial. The aim of this study was to determine the predictive value of maternal anti-SS-A antibodies on the development of fetal CHB. Methods A retrospective chart review was performed for 189 cases of positive anti-SS-A antibodies determined by the double immunodiffusion(DID) method, and included 17 patients that developed fetal CHB. The relationship between the appearance of CHB and the anti-SS-A antibodies titerwas examined. Results An anti-SS-A antibodies titerof 1:32 or higher was identified by analyzing the receiver-operating characteristics (area under curve 0.72) curve. An anti-SS-A antibodies titerof 32 or more times greater than the upper limit by DID was a risk factor for fetal CHB (odds ratio 27.77, 95 % confidence interval (CI) 1.91‐21.02, P \ 0.05) in the multivariate analysis. Among 107 cases of anti-SS-A antibodies titersof 1:32 or higher, 65 patients (60.7 %) were treated with oral steroids. Of these, four patients had CHB (6.2 %). This rate of CHB was significantly lower (P \ 0.01) than the rate in patients not treated with steroids. Conclusion An anti-SS-A antibodies titerof 1:32 or higher in the maternal sera by DID was an independent risk factor for fetal CHB. In these patients, either antenatally administered prednisolone or betamethasone, was associated with a lower risk of fetal CHB.