Despite increasing pressure to decrease hospital length of stay (LOS), little is known of what factors influence LOS in preterm infants. Using regression analysis, we explored the relationship between NICU LOS and a number of perinatal and demographic factors in all surviving infants with birthweight (BW) ≤1500g born at JHH 9/1/94-8/31/95 who were not back-transported to Level III NICUs. The study sample consisted of 91 infants, with a mean BW of 1072 ± 235g (range 560-1500) and mean gestational age(GA) of 28.5 ± 2.4 wks (range 24-36). Half (52%) were male, 64% received medical assistance (MA), 13% were small for gestational age (SGA), 17% had intracranial hemorrhage (ICH) and 3% had intraparenchymal (IP) cysts. Only the following variables were significantly related to prolonged NICU LOS: duration of ventilation, GA, ICH, private insurance or HMO, abnormalities on neonatal neurodevelopmental examination, IP cysts and SGA. Maternal age, gender, duration of oxygen, Apgar at 5 min, weight at 36 wks postmenstrual age(PMA) and a measure of neurological maturity at 32 wks PMA were not related to NICU LOS.

CONCLUSION: Variables related to immaturity/size at birth, CNS injury and insurance status predict NICU LOS in VLBW preterm infants. Reducing NICU LOS will require efforts aimed at prolonging pregnancy and reducing neonatal complications in very low birthweight infants.