Predictors of Mortality in Neonates With Persistent Pulmonary Hypertension: A Retrospective Cohort Study

Objective: Persistent pulmonary hypertension of the newborn (PPHN) is associated with substantial morbidity and mortality. This study aimed to evaluate demographic, perinatal, umbilical cord blood gas, and echocardiographic parameters as potential predictors of in-hospital mortality in neonates with PPHN. Materials and Methods: This retrospective cohort study included neonates admitted to the neonatal intensive care unit between January 1, 2019, and December 31, 2021, with a documented clinical and echocardiographic diagnosis of PPHN. Patients were eligible if they were 0 to 28 days of age, had a gestational age greater than 24 weeks, and had available umbilical cord blood gas data. The primary outcome was in-hospital mortality. Univariable and multivariable logistic regression analyses were used to evaluate factors associated with mortality. Results: A total of 51 neonates were included in the final analysis. The median gestational age was 35 weeks, and the median birth weight was 2480 g. In-hospital mortality occurred in 16 patients (31.4%). Female sex was more frequent among non-survivors than survivors (75.0% vs. 34.3%, p=0.007). Survivors had higher gestational age than non-survivors [36 weeks (IQR, 33 to 38) vs. 31.5 weeks (IQR, 25.3 to 35.8), p=0.015]. Survivors also had higher 1-minute and 5-minute Apgar scores than non-survivors. Umbilical cord blood gas parameters and estimated pulmonary artery systolic pressure values did not differ significantly between groups. In multivariable logistic regression analysis, male sex (adjusted OR, 0.12; 95% CI, 0.02 to 0.60; p=0.010) and higher 1-minute Apgar score (adjusted OR, 0.67; 95% CI, 0.47 to 0.95; p=0.025) were independently associated with lower odds of in-hospital mortality. Conclusion: In this cohort of neonates with PPHN, in-hospital mortality was high. Male sex and higher 1-minute Apgar score were independently associated with lower mortality risk, whereas umbilical cord blood gas parameters and estimated pulmonary artery systolic pressure were not significant predictors. Our findings suggest that clinical indicators assessed particularly during the early postnatal period may be useful in predicting the risk of mortality in the neonatal intensive care unit.