Neonatal pacing for immune mediated complete heart block diagnosed antenatally at 27 weeks: a case report with successful outcome

Abstract

Congenital complete heart block (CCHB) is a rare condition, most commonly associated with maternal autoimmune antibodies such as anti-Ro/SSA. We report a case of antenatally diagnosed immune-mediated CCHB at 27 weeks’ gestation in a 27-year-old gravida 2 woman with positive antinuclear and anti-Ro/SSA antibodies. Fetal echocardiography revealed complete heart block in a structurally normal heart with a ventricular rate of 55 bpm. The pregnancy was managed with maternal dexamethasone and hydroxychloroquine, with close fetal surveillance. A late preterm infant weighing 2.4 kg was delivered at 36 weeks and required permanent pacemaker implantation within 24 hours of life due to persistent bradycardia. The postnatal course was uneventful, and at 3-month follow-up, the infant demonstrated stable pacemaker function with appropriate growth and development. This case highlights the importance of early diagnosis, multidisciplinary perinatal management, and timely neonatal pacing in achieving favourable outcomes in immune-mediated CCHB.