Morbidity and Mortality Trends in Preterm Infants of

Abstract

Owing to advances in critical care treatment, the overall survival rate of preterm infants born at a gestational age (GA) <32 weeks has consistently improved. However, the incidence of severe intraventricular hemorrhage (IVH) has persisted, and there are few reports on in-hospital morbidity and mortality. Therefore, the aim of the present study was to investigate trends surrounding in-hospital morbidity and mortality of preterm infants with severe IVH over a 14-year period. This single-center retrospective study included 620 infants born at a GA <32 weeks, admitted between January 2007 and December 2020. After applying exclusion criteria, 596 patients were included in this study. Infants were grouped based on the most severe IVH grade documented on brain ultrasonography during their admission, with grades 3 and 4 defined as severe. We compared in-hospital mortality and clinical outcomes of preterm infants with severe IVH for two time periods : 2007-2013 (phase I) and 2014-2020 (phase II). Baseline characteristics of infants who died and survived during hospitalization were analyzed. A total of 54 infants (9.0%) were diagnosed with severe IVH over a 14-year period; overall in-hospital mortality rate was 29.6%. Late in-hospital mortality rate (>7 days after birth) for infants with severe IVH significantly improved over time, decreasing from 39.1% in phase I to 14.3% in phase II (p=0.043). A history of hypotension treated with vasoactive medication within 1 week after birth (adjusted odds ratio, 7.39; p=0.025) was found to be an independent risk factor for mortality. When comparing major morbidities of surviving infants, those in phase II were significantly more likely to have undergone surgery for necrotizing enterocolitis (NEC) (29.2% vs. 0.0%; p=0.027). Additionally, rates of late-onset sepsis (45.8% vs. 14.3%; p=0.049) and central nervous system infection (25.0% vs. 0.0%; p=0.049) were significantly higher in phase II survivors than in phase I survivors. In-hospital mortality in preterm infants with severe IVH decreased over the last decade, whereas major neonatal morbidities increased, particularly surgical NEC and sepsis. This study suggests the importance of multidisciplinary specialized medical and surgical neonatal intensive care in preterm infants with severe IVH.