Neonatal Intensive Care Quality Level-Dependent Variations in the Survival Rate of Infants with a Birth Weight of 500 g or Less in Korea: A Nationwide Cohort Study

Objective: Recent evidence suggests that the survival of peri-viable infants with birth weight (BW) ≤500 g could be improved with better care practices in the neonatal intensive care unit (NICU). This study aimed to investigate the care quality level of NICU-dependent variations in the survival rate of infants with BW ≤500 g. Methods: To determine the quality of NICU care-dependent variations in the survival rate, 226 eligible infants of BW ≤500 g and ≥22 weeks gestation registered in the Korean Neonatal Network between 2013 and 2017 were grouped according to the survival rates of infants at 23–24 weeks gestation, reflecting the care quality level of each NICU as group I (≥50%, n = 107) and group II (<50%, n = 119). Results: The survival rate of group I infants (40.2%, 43/107) was significantly higher than that of group II infants (14.3%, 17/119). Significantly reduced deaths from birth to the age of 7 days due to cardiorespiratory causes were the primary contributors to improved survival. In multivariable Cox hazard model analyses, besides the gestational age and BW, antenatal steroid use, cesarean section, pH, and base excess at admission were associated with improved infant survival. Conclusions: The survival rate of pre-viable infants with BW ≤500 g could be improved by providing better NICU quality care practices, including better cardiorespiratory management starting from delivery room resuscitation.