Extracorporeal membrane oxygenation in Non-Immune Hydrops fetalis – a registry-based data analysis over the last 25 years

Non-immune hydrops fetalis (NIHF) is a rare condition that can lead to serious cardiopulmonary compromise after birth, often resulting in the need for intensive cardiorespiratory support, and in selected cases including extracorporeal membrane oxygenation (ECMO). Outcome is complicated due to a high rate of preterm birth. Morbidity and mortality data regarding NIHF and outcome of ECMO treatment in this population are very sparse. This is the first update and analysis of the Extracorporeal Life Support Organization (ELSO) registry-based data of neonates with NIHF. Neonatal patients with a diagnosis of NIHF and treated with ECMO during the years 2000-2024, reported to the ELSO registry, were retrospectively analyzed. Exclusion criteria were HF due to hemolytic disease, congenital diaphragmatic hernia (CDH), and major cardiac defects. After the application of exclusion criteria, 171 patients remained for final analysis, of these 88 (52%) survived until discharge. Infants with a higher birth weight (p = .011) and those with a gestational age (GA) ≥ 35 weeks (p = .032), as well as female patients (p = .027), had significantly higher in-hospital survival rates. The ECMO support type (veno-arterial vs. veno-venous) did not influence in-hospital mortality rate (p = .524) or complication rate. Female sex and higher BW (> 2.5 kg) remained independently associated with higher in-hospital survival after a binary logistic regression analysis. CONCLUSION: Mortality rates over the last 25 years remained largely unchanged. Our analysis revealed baseline characteristics as independent predictors for higher in-hospital survival in these patients. In comparison with other underlying conditions treated with neonatal ECMO, neonates with NIHF present comparable morbidity and mortality rates after veno-arterial or veno-venous ECMO treatment. WHAT IS KNOWN: • NIHF is a rare neonatal disease leading to preterm birth and a high risk of cardiorespiratory compromise, sometimes resulting in the need for ECMO treatment. • ECMO treatment for preterm infants is feasible, with increasing survival rates. WHAT IS NEW: • After ECMO treatment, neonates with NIHF show acceptable complication rates and in-hospital survival, supporting a case-selective discussion of ECMO therapy. • Both veno-arterial and veno-venous ECMO are potential rescue therapy options in experienced neonatal ECMO centers with comparable outcomes.