Objective: To determine the number and outcome of infants with BW < 501 g at 54 Neonatal Intensive Care Units participating in the Vermont Oxford Neonatal Network. Methods: Pre-defined perinatal and neonatal outcome data were collected on standardized forms for all live births with BW < 501 g during one year (June 1, 1994 - May 31, 1995). Results: There were 391 liveborn infants evaluated of whom 95 were intubated and ventilated, and 296 were not. Ventilated infants, compared to non-ventilated infants, were more likely to have received antenatal steroids (35% vs. 4%, p<0.001), to be delivered by cesarean section (43% vs. 4%, p<0.001), to be more mature(mean gestational age 24 weeks vs. 21 weeks, p<0.001), and to be heavier(mean BW 444 g vs. 370 g, p<0.001). Most deaths (81%) occurred within the first day of life; few infants (1%) died after 28 days. No infant born less than 320 grams or less than 22 weeks survived. Twenty four infants survived to discharge, all of whom were ventilated, and received surfactant. Among survivors, 22 of 24 (92%) received steroids for chronic lung disease. One survivor had grade IV intraventricular hemorrhage (IVH), whereas 17 of 24(71%) had no IVH. The mean hospital stay for survivors was 127 ± 22 days. Conclusions: Some infants with BW < 501 g selected for intubation and ventilation can survive to discharge to home. Further study will be needed to better understand the selection criteria used to offer resuscitation to these extremely low BW infants, and determine the long term neurodevelopmental outcome of the survivors.

Supported by a grant from the Center for the Future of Children of the David and Lucile Packard Foundation.