Echogenic Fetal Heart Without Conduction Defect in Maternal Autoimmune Disease: A Lesser Known Association

Abstract

Positive anti-Ro/SSA and anti-La/SSB antibodies in pregnant mothers are strongly associated with fetal congenital heart block (CHB). Increased echogenicity of fetal endo-myocardium is one of the lesser known manifestations of maternal autoimmune disease. In this retrospective analysis of data from the last ten years (2010-2019) at our fetal medicine unit, we identified nine fetuses presenting in the second trimester with isolated increased echogenicity of the endo-myocardium without CHB. In three cases, mothers had a pre-existing autoimmune disease. The others were diagnosed with positive autoimmune antibodies following evaluation for the echogenic fetal heart. One fetus developed a first-degree heart block at 33 weeks and another had a second-degree heart block three weeks after presentation. There was no fetal mortality. All were live-born. One fetus with tachycardia and ventricular dysfunction died within a few days of birth. Both babies with heart block are stable and on medical follow-up, while others remain asymptomatic with a normal rhythm. There seems a spectrum of fetal disease caused by maternal auto-antibodies affecting the endomyocardium but sparing the conduction system. In fetuses with echogenic hearts, evaluation of maternal autoimmune status should be part of the protocol for optimal fetal and maternal care.