Clinical profile and predictors of mortality in neonates born with non-immune hydrops fetalis: Experience from a lower-middle-income country

Introduction: Hydrops fetalis (HF) is a life-threatening condition in which a fetus has an abnormal collection of fluid in the tissue around the lungs, heart, abdomen, or under the skin. Based on its pathophysiology, it is classified into immune and non-immune types. With the widespread use of anti-D immunoglobulin, non-immune HF has become more common, with an incidence of one in 1,700-3,000 live births. A multitude of fetal diseases with various causes can lead to non-immune HF. Due to the recent advances in prenatal diagnostic and therapeutic interventions together with improved neonatal intensive care, the diagnosis and subsequent management of HF have been refined. However, HF is still associated with a high mortality rate. A recent assessment of the literature found that there is a lack of data on prognostic variables in neonates with HF from low- and middle-income countries. In light of this, we sought to establish the etiologic causes, predictors of mortality, and eventual fate of newborns born non-immune HF at the Aga Khan University Hospital, Karachi during the 10-year period spanning January 2009-December 2019 in this retrospective analysis.Methodology: For this study, we collected data from the computerized database and patient record files at the hospital on all infants with non-immune HF. Demographic data, postnatal interventions, clinical and laboratory findings, outcomes, and the results of comparison between HF patients who died and those who survived were analyzed.Results: The incidence of non-immune HF at our hospital was 0.62/1,000 live births during the period under study, with 33 newborn babies diagnosed with non-immune HF from a total of 53,033 live-born deliveries. An etiologic factor was discovered in 17 (51.5%) neonates with non-immune HF while 16 (48.4%) were classified as those with unidentified etiology. The most common causes were cardiovascular and genetic syndromes, which resulted in 100% mortality. The overall mortality rate was 67%. The need for mechanical ventilation, surfactant therapy, and prolonged hospitalization were identified as independent risk factors of mortality.Conclusion: Our study proves that the need for mechanical ventilation [moderate to severe hypoxic respiratory failure (HRF)] and prolonged hospitalization are strong predictors of poor outcomes in neonates with non-immune HF. Therefore, severe hydrops causing significant mortality can be anticipated based on the patients\u27 respiratory status and the need for escalated oxygen support