Improved Outcomes of Very Low Birth Weight Infants in Korea: 2015-2016 vs. 2021-2022 From the Korean Neonatal Network

Abstract

Background: This study aimed to analyze improvements in the survival rates and morbidities of very low birth weight infants (VLBWIs) in the Republic of Korea from 2015 to 2022. Methods: Data from the Korean Neonatal Network were used to assess survival and morbidity trends among VLBWIs, particularly focusing on changes across different gestational ages. The analysis included a comparison with data from other neonatal networks, such as the Australian and New Zealand Neonatal Network, Canadian Neonatal Network, Swedish Neonatal Quality Register, Neonatal Research Network Database Japan, and United States National Vital Statistics Reports, to understand differences in survival and morbidity outcomes. Results: The survival rate of VLBWIs in Korea rose from 86% in 2015-2016 to 91% in 2021-2022. This increase was most notable in infants born before 28 gestational weeks, with significant gains observed among those born at 24 (67% in 2021-2022 compared with 51% in 2015-2016, P < 0.001), 25 (80% in 2021-2022 versus 66% in 2015-2016, P < 0.001), and 26 (89% in 2021-2022 compared to 79% in 2015-2016, P < 0.001) gestational weeks. Compared with other networks, the survival rates of Korean VLBWIs, except for infants born before 24 gestational weeks whose survival rates remain significantly lower, have largely caught up with those of high-income countries. The incidence of major morbidities such as severe intraventricular hemorrhage, necrotizing enterocolitis, and sepsis also showed a decreasing trend. However, incidence rates ofbronchopulmonary dysplasia and periventricular leukomalacia remained relatively high, especially for infants born before 24 gestational weeks. Conclusion: Although outcomes have improved significantly in Korea, further efforts are needed to enhance survival rates of infants born before 24 gestational weeks. Focused interventions and improvements in clinical practices are essential to achieve better outcomes for these vulnerable infants.