Daily mortality of infants born at less than 30weeks' gestation

Abstract

Background: Few studies have reported odds of mortality for hospitalized premature infants stratified by postnatal age and adjusted for severity of illness. Our objective was to examine day-by-day mortality of premature infants in a large multicenter cohort of infants, adjusted for demographics, severity of illness, and receipt of therapeutic interventions.

Methods: This was a multicenter cohort study of infants cared for in 362 neonatal intensive care units with a shared clinical data warehouse from 1997 to 2013. We included all inborn infants born at 22-29weeks' gestational age with available mortality discharge data. We report the point prevalence of survival to hospital discharge stratified by gestational and postnatal age.

Results: We identified 64,896 infants, of whom 55,348 (85%) survived to hospital discharge. Survival increased with gestational and postnatal age, until infants reached a postmenstrual age of approximately 37weeks, after which survival began to decrease. Overall survival increased over time (80% in 1997 to 88% in 2013, P<.001).

Conclusions: Given the known association between gestational age and postnatal age, survival predictions should be adjusted for both covariates.

Keywords: Gestational age; Mortality; Premature infant.