Difference in Mortality and Morbidity Between Extremely and Very Low Birth Weight Neonates

Abstract

Purpose: The aim of the present study was to evaluate the mortality and morbidity of extremely low (ELBW < 1,000 g) and very low birth weight neonates (VLBW: 1,000-1,500 g) hospitalized in a referral NICU of a Children's hospital. Design: A retrospective study was conducted in records of the Neonatal Unit of a tertiary care Children's hospital in Greece from January 2009 to March 2019. Sample: All neonates with birth weight ≤1,500 grams, who were all outborn, were reviewed. Main Outcome Variable: Mortality and morbidity, including respiratory distress syndrome, bronchopulmonary dysplasia, intraventricular hemorrhage, periventricular leukomalacia, necrotizing enterocolitis, early onset sepsis, late onset sepsis, retinopathy of prematurity (ROP), ROP treated with laser and neurological findings were investigated. Results: A total of 444 neonates (52 percent males) were analyzed. Among them, 187 (42 percent) were ELBW and 257 (58 percent) were VLBW. The mean gestational age was lower in ELBW neonates compared to VLBW (26.3 ± 2.3 vs. 29.7 ± 2.4 weeks, respectively; p < .001). Mortality was significantly higher in ELBW compared to VLBW neonates (26.7 percent vs. 7.0 percent, p < .001). Morbidity was significantly higher in ELBW compared to VLBW for respiratory distress syndrome (p < .001), bronchopulmonary dysplasia (p < .001), intraventricular hemorrhage (p < .001), periventricular leukomalacia (p < .001), necrotizing enterocolitis (p = .05), early onset sepsis (p < .001) and late onset sepsis (p = 0.001). Similarly, the incidence of ROP and ROP treated with laser was higher in ELBW compared to VLBW neonates (p < .001). Severe neurological findings during follow-up were more prevalent in ELBW compared to VLBW neonates. Finally, the incidence of eye disorders was higher in ELBW compared to VLBW (p = .05). Conclusion: Our results confirmed that ELBW have higher mortality and morbidity than VLBW neonates. Efforts should be made in order to ameliorate perinatal and neonatal care to reduce the burden of prematurity.

Keywords: NICU; low birth weight; morbidity; mortality; neonate.