Preventive IVIG Therapy for Congenital Heart Block

Study Summary

Neonatal lupus (NL) is the name given to a group of conditions that can affect the babies of mothers who have certain autoantibodies against components of the body's cells that are called SSA/Ro and SSB/La. NL can appear as a temporary rash that usually goes away by the time the baby is 6 months old, or very rarely an abnormal blood or liver condition that also improves with time - or it can cause permanent and often life-threatening damage to the fetal heart, known as congenital heart block (CHB). In women with anti-Ro/La antibodies who are pregnant for the first time, only about 2% of the babies will develop CHB. But for a woman who has already had a child with CHB or NL rash, the risk of CHB in her next pregnancy is nearly 20%. Unfortunately, once complete (third degree) heart block has been unequivocally identified in a fetus, it has never been reversed with any of the therapies that have been tried to date. Our previous studies strongly indicate that scarring of the conduction system (the heart's own natural "pacemaker"), a consequence of inflammation triggered by the mother's antibodies, damages or even destroys the cells that allow the heart to beat at a normal rhythm. Instead, the damaged heart beats extremely slowly, to an extent that is fatal to nearly 20% of affected babies (with most deaths occurring as fetal demises). Nearly all surviving children with CHB require permanent implantation of a pacemaker device. Because it is so difficult to treat or repair the damaged heart, a high-priority strategy is to try to prevent the inflammatory process before irreversible scarring can occur. The aim of this clinical-based proposal is to determine whether treating the pregnant mother with intravenous immune globulin (IVIG) will prevent the development of CHB.

Interventions

• DRUG intravenous immune globulin (IVIG)