Trends of Mortality, Time, and Causes of Death in Preterm Infants

Objective: Although survival rate of preterm infants in Korea has increased in the past several decades, it seems to be stable recently. The objective of this study is to evaluate the mortality rate of preterm infants in a single center in Korea between 2009 and 2018.Methods: Preterm infants with gestational age (GA) <30 weeks who were admitted to Busan Paik Hospital (January 2009 to December 2018) were enrolled.Results: The overall mortality rate was 20.8%. Mortality rate decreased from 21.9% in 2009 to 9.2% in 2012. It then increased and reached a plateau at 20%. Mortality rate was 80.0% in those with GA of 22 weeks. It then decreased with increasing GA. It was 2.9% in those with GA of 29 weeks. The risk of death decreased by 0.573 times when GA increased by 1 week. Death immediately after birth was high in infants with GA of 22 weeks. It was rare in infants with GA ≥25 weeks. Death within 24 hours after birth was high in infants with GA ≤24 weeks who were delivered precipitately without appropriate perinatal support. Sepsis was the leading cause of all deaths. High grade intraventricular hemorrhage was the second common cause of death, especially in infants with GA ≤24 weeks.Conclusion: Mortality rate of preterm infants in this study did not decrease. Modifiable factors including delivery with appropriate supports of neonatal resuscitation team and sufficient maternal obstetric care, especially maternal infection control might reduce mortality, especially immediate postnatal death.