Survival until Discharge of Very-Low-Birth-Weight Infants in Two Croatian Perinatal Care Regions: A Retrospective Cohort Study of Time and Cause of Death

We investigated mortality, causes, timing and risk factors for death until hospital discharge in very-low-birth-weight (VLBW) infants born in two Croatian perinatal care regions. This retrospective study included 252 live born VLBW infants. The mortality rate until hospital discharge was 30.5% (77/252). VLBW infants who died had by 4 weeks lower gestational age (GA) than surviving infants (median GA, 25 <i>vs</i>. 29 weeks), lower birth weight (BW) (mean BW, 756.4 <i>vs</i>. 1126.4 g), lower 5-minute Apgar score (median 5 <i>vs</i>. 8) and were more often resuscitated at birth (41.6 <i>vs</i>. 19.4%; p<0.001 all). Infants who survived were more often small-for-gestational age (SGA) (28.0 <i>vs</i>. 15.6%; p=0.04) and more often received continuous-positive-airway-pressure (CPAP) in delivery room (13.1 <i>vs</i>. 2.6%; p=0.01). Multivariate logistic regression revealed that parameters influencing death until hospital discharge were 5-minute Apgar score (OR 0.780, 95% CI 0.648-0.939) and higher Clinical Risk Index for Babies (CRIB) score (OR 1.677, 95% CI 1.456-1.931). ROC analysis showed that CRIB score (AUC 0.927, sensitivity 92.2, specificity 81.1; p<0.001) was the strongest predictor of death until hospital discharge. In infants who died within 12 hours, death was most commonly attributed to immaturity and in those surviving >12 hours to necrotizing enterocolitis.