Discharge Age and Weight for Very Preterm Infants: 2005-2018

A complex set of medical, social, and financial factors underlie decisions to discharge very preterm infants. As care practices change, whether postmenstrual age and weight at discharge have changed is unknown.

Between 2005 and 2018, 824 US Vermont Oxford Network member hospitals reported 314 811 infants 24 to 29 weeks' gestational age at birth without major congenital abnormalities who survived to discharge from the hospital. Using quantile regression, adjusting for infant characteristics and complexity of hospital course, we estimated differences in median age, weight, and discharge weight z score at discharge stratified by gestational age at birth and by NICU type.

From 2005 to 2018, postmenstrual age at discharge increased an estimated 8 (compatibility interval [CI]: 8 to 9) days for all infants. For infants initially discharged from the hospital, discharge weight increased an estimated 316 (CI: 308 to 324) grams, and median discharge weight z score increased an estimated 0.19 (CI: 0.18 to 0.20) standard units. Increases occurred within all birth gestational ages and across all NICU types. The proportion of infants discharged home from the hospital on human milk increased, and the proportions of infants discharged home from the hospital on oxygen or a cardiorespiratory monitor decreased.

Gestational age and weight at discharge increased steadily from 2005 to 2018 for survivors 24 to 29 weeks' gestation with undetermined causes, benefits, and costs.