Late Gestation Fetal Growth in Infants Undergoing Stage 1 Palliation for Single Ventricle Heart Disease

Improved understanding of late gestation fetal growth patterns and postnatal outcomes in fetuses with single ventricle heart disease may inform decisions about elective delivery timing. This was a retrospective cohort analysis of patients in the National Pediatric Cardiology Quality Improvement Collaborative database from 2016 to 2019 anticipated to need stage 1 palliation (S1P) and had a gestational age (GA) of ≥ 36 weeks. Birthweight (BW) and BW z-scores were compared across GA. Survival to stage 2 palliation (S2P), post-S1P length of stay, and duration of mechanical ventilation were compared by GA. In 1290 infants, the mean BW increased with increasing GA (p < 0.001). Mean BW z-scores were below zero in late gestation (p < 0.001), with declining growth velocity 38 to > 40 weeks GA. Of 1216 patients with mechanical ventilation data, those at later GA had shorter durations of ventilation (p < 0.001). Among 1083 survivors to discharge or S2P if not discharged, infants born at later GA had shorter S1P hospitalizations (p = 0.015) and were more likely to undergo S2P (p = 0.003). Infants with single ventricle heart disease requiring S1P have decreased late gestation growth velocity, but growth continues. Infants born after longer gestation have shorter duration of ventilation and greater likelihood of undergoing S2P.