Epidemiology and Differential Burden of Benign and Pathologic Neonatal Arrhythmias by Gestational Age

BACKGROUND AND OBJECTIVES Premature infants may be at increased risk for arrhythmias, yet population-based data describing arrhythmia prevalence across finely stratified gestational age groups are limited. We aimed to quantify the burden of benign and pathologic arrhythmias across GA strata using a nationally representative dataset. METHODS We conducted a retrospective cross-sectional study using the National Inpatient Sample (2016-2022), including all liveborn infants hospitalized in US hospitals. GA was categorized as less than 25, 25 to 28, 29 to 32, 33 to 36, 37 to 40 (term), and ≥41 weeks. Arrhythmias were classified as benign or pathologic. Survey-weighted prevalence estimates were calculated. Multivariable logistic regression was used to evaluate associations between GA and arrhythmia risk, with term infants as the reference and adjustment for clinical and demographic confounders. RESULTS Among 25 463 003 newborns, the overall prevalence of any arrhythmia was 1.93%. Prevalence increased with decreasing GA, peaking among infants born at 29 to 32 weeks (27.0%) and 25 to 28 weeks (25.0%). In adjusted analyses, the odds of any arrhythmia were highest in infants born at 29 to 32 weeks (23-fold) and 25 to 28 weeks (13-fold) compared with term infants. For pathologic arrhythmias, adjusted risk was greatest in the group born at 33 to 36 weeks (3.1-fold). Congenital heart disease (CHD) was the strongest predictor of pathologic arrhythmias (27-fold increased odds), and neonatal infection was independently associated with both benign and pathologic arrhythmias. CONCLUSIONS Neonatal arrhythmias are substantially more common in preterm infants, with the highest risk clustering between 29 and 36 weeks’ gestation. GA is an important marker of arrhythmia risk, warranting heightened vigilance, particularly among infants with CHD or systemic infection.