Congenital heart block related to maternal autoantibodies: descriptive analysis of a series of 18 cases from a single center

The objective of this study was to describe the clinical and immunological characteristics of maternal autoimmune-mediated fetal congenital heart block (CHB) in a cohort of pregnant women from an autoimmune disease pregnancy clinic. This is a retrospective observational study of all women presenting with CHB in our autoimmune disease pregnancy clinic from January 1997 to December 2014. In addition, perinatal outcome is also described. Fourteen patients accounting for 18 fetuses with CHB were identified. The median age was 32.5 years (range, 22–40). Seven (50 %) patients had Sjögren’s syndrome, and the remaining seven were asymptomatic carriers of autoantibodies. All patients had anti-Ro/SSA antibodies, and 11/13 (85 %) had anti-La/SSB antibodies. The median gestational age at the time of CHB was 22 weeks (range 18–28). Complete third degree CHB was detected in 12 (67 %). Seven cases of CHB were treated with dexamethasone, two with ritodrine, and one with the association of dexamethasone, ritodrine, and terbutaline. In 9 (50 %) cases that presented with, or developed, very poor prognosis factors, such as a ventricular rate below 50–55 bpm and/or the presence of fetal hydrops, parents opted for the termination of pregnancy, after dedicated counseling. Finally, there were nine newborns (seven males [78 %]) with median age at delivery of 37 weeks (range, 32–39). A definitive epicardial pacemaker was placed in six newborns, four of them within 2 weeks of life. CHB is a severe complication related to maternal anti-Ro/SSA and anti-La/SSB antibodies. Our results confirm previous data showing that therapy is ineffective, and most of the surviving patients will require neonatal pacemaker.