A Prospective Study of Neonates with Persistent Pulmonary Hypertension of the Newborn: Prevalence, Clinical Outcomes, and Risk Factors

Background: Persistent pulmonary hypertension of the newborn (PPHN) is caused by the inability of the pulmonary arteries to dilate at birth, which leads to severe hypoxemia. Several risk factors have been identified in association with its occurrence and prognosis. The present study aimed to determine the incidence of PPHN, describe neonates' characteristics, and evaluate the etiology, as well as mortality risk factors in newborns hospitalized due to PPHN at Bahrami Children's Hospital, Tehran, Iran, from 2017 to 2020. Methods: A total of 49 neonates were included in the present study. The PPHN diagnosis was based on clinical criteria and echocardiography provided by neonatologists. Therefore, a complete history, physical examination, and laboratory data were gathered. Afterward, PPHN etiology was determined, and the patients were followed up for six months. Finally, PPHN prevalence was calculated and probable risk factors for its complications were investigated by using logistic regression analysis. Results: The findings revealed that the prevalence of PPHN was 3.5% in the center under study, and the mortality rate, as well as complete recovery, were 24.5% and 63%, respectively. It was also found that factors, such as male gender, abnormal Apgar score at birth, and cesarean delivery, were high in a percentage of PPHN patients; however, they were not associated with PPHN mortality and morbidity. The only variable that had a significant association with mortality and morbidity was an abnormal white blood cell count. Conclusion: The need for inotropic support was associated with poor outcomes. From the aspect of etiology, there exists higher mortality rates, complications, and poor prognosis among PPHN patients with underdevelopment, compared to the ones with maldevelopment.