Prevention of congenital heart block in children of SSA-positive mothers.

The incidence of congenital heart block (CHB) in the offspring of anti-Ro-positive women is approximately 1-2%, and the risk of recurrence is 10 times higher in the following pregnancies. Non-fluorinated steroids (prednisone, prednisolone and methylprednisolone) are recommended only for maternal indications, not for prevention of CHB in anti-Ro/SSA-positive women. Fluorinated steroids (dexamethasone or bethametasone) are not metabolized by the placenta and are available to the fetus in an active form. Routine prophylactic therapy with fluorinated steroids is not recommended even in women who previously had children with CHB or skin rash since this therapy has its own side-effects. Intravenous immunoglobulin had been used to prevent the development of CHB in 8 high risk mothers (anti-Ro/SSA positive and previous pregnancy with CHB), and in one case CHB recurred (12.5%). At present, the only sure recommendation that can be made in these women is that in the presence of reliable positivity for anti-Ro/SSA antibodies serial echocardiograms and obstetric sonograms should be performed at least every 2 weeks starting from the 16th week of gestational age: the goal is to detect early fetal abnormalities, such as premature atrial contractions or moderate pericardial effusion, that might precede complete atrioventricular block and that might be a target of preventive therapy. Fluorinated steroids should not be used in the absence of symptoms; in the presence of alarming symptoms, betamethasone seems safer than dexamethasone.