Fetal treatment of congenital heart block ascribed to anti-SSA antibody: case reports with observation of cardiohemodynamics and review of the literature.

PROBLEM: Maternal anti-SSA(B) antibody crosses the placenta and causes fetal myocarditis, congenital heart block (CHB), hydrops fetalis, and intrauterine fetal death. The aim of this study was to evaluate corticosteroids' efficacy as a treatment for CHB.

METHOD OF STUDY: One fetus with complete CHB and one fetus with incomplete CHB due to anti-SSA(B) antibody received maternal prednisolone (PSL) and dexamethasone (DEXA) treatments. Heart rate, cardiothoracic ratio (CTR), left ventricular fractional shortening (FS), and preload index (PLI) were longitudinally measured by serial fetal echocardiograms.

RESULTS

In the former case, after maternal PSL/DEXA administration, improvement of cardiohemodynamics, i.e., the reduction of PLI from 1.7 to 0.4, CTR from 70 to 52%, and FS from 63 to 54% were observed. In the latter case, second degree 2:1 block was converted to 3:2 block/sinus rhythm, resulting in the increase of the fetal heart rate from 65 to 116 beats per minute (bpm).

CONCLUSIONS

We disclosed for the first time the beneficial effects of corticosteroids in the fetal cardiohemodynamics and conduction system of affected fetuses with the presence of maternal anti-SSA(B) antibodies.