Fetal dysrhythmias and their postnatal follow-up: Observations from a tertiary referral center in Northern India

Background: Fetal cardiac rhythm abnormalities affect approximately 2% of pregnancies, with a subset posing significant hemodynamic risks to the fetus. Timely identification and intervention are critical to optimizing outcomes. This study evaluates the types, associations, management, and postnatal outcomes of abnormal fetal cardiac rhythms at a tertiary care center in North India. Methodology: A prospective observational study was conducted at the Children’s Hospital, Bemina, from January 2023 to February 2025. All foetuses referred with suspected arrhythmias underwent detailed fetal echocardiography. Arrhythmias were classified as tachyarrhythmias, bradyarrhythmias, or ectopic beats. Maternal autoimmune status was assessed in relevant cases. Transplacental therapy (TPT), including digoxin, flecainide, and amiodarone, was administered for tachyarrhythmias. Steroids and hydroxychloroquine were used in autoimmune-mediated conduction abnormalities. Cases were followed until delivery and postnatally. Results: Thirty-seven fetuses with abnormal rhythms were evaluated. Premature artial contraction (PACs) were the most common(45.9%) followed by conduction defects(27%) and Supraventricluar Tachycardia and AF(18.9%). Structural heart defects were present in 16.2% of cases. TPT was successful in five of seven tachyarrhythmia cases. Immune-mediated AV block was noted in 60% of conduction abnormalities. Postnatal outcomes included healthy deliveries in most PAC cases, pacemaker insertion in one neonate with complete heart block, and intrauterine demise in three hydropic fetuses. Conclusion: Abnormal fetal cardiac rhythms can range from benign to life-threatening conditions. Prompt diagnosis with fetal echocardiography, maternal autoimmune screening, and targeted intrauterine management play pivotal roles in improving neonatal outcomes. Multidisciplinary care is essential for optimal perinatal management.