Predictors of early neonatal mortality in extremely low birth weight infants in a Neonatal Intensive Care Unit over a 10-year period

Background: Early neonatal mortality (ENM) contributes substantially to overall mortality rates. Reliable cause-specific data are valuable; thus, the definition of risk factors provides information on antenatal, perinatal and immediate neonatal management. Objective: The present study was designed to investigate rates of ENM within extremely low birth weight (ELBW) infants group, to define associated antenatal, perinatal and neonatal factors associated with ENM and also primary causes of early death. Methods: Case records of consecutive ELBW infants admitted to our Neonatal Intensive Care Unit over a 10-year period were retrospectively surveyed for the deaths up to 7 days postpartum. Logistic regression modeling was used to determine the association of risk factors with ENM. Results: Infants included (n = 359) were classified into non-survivors (cases, n = 80) and survivors (controls, n = 231) during the first 7 days while non-survivors after 7 days of life (n = 48) were excluded. Survival analysis showed that most of the early deaths occurred within 48 hours postpartum. The overall ENM rate was 25.7%, with no significant variation over time. Predictors as gestational age, birth weight, gender, chorioamnionitis, preeclampsia, intrauterine growth retardation, antenatal steroids administration (ASA), Apgar score at 1 minute, perinatal acidemia and surfactant doses were involved for early death. All results were adjusted for possible confounders. Specifically, until 48 hours of life ASA decreased odds for death. The main immediate causes of death until the first 48 hours were prematurity and pulmonary hemorrhage, while from 48 hours to 7 days were prematurity and pulmonary insufficiency. Conclusions: ENM rates occurred mainly during 2 postnatal days, did not show significant improvement over time and as related to certain factors can be modified with simple targeted perinatal policies.