PURPOSE: The outcomes of infants weighing less than 1,500 gm(very low birth weight infant : VLBWI) reflect recent progress in neonatal intensive care. In this study, we analyzed changes over time in survival rate and morbidity of VLBWIs during the past seven years.
METHODS: A retrospective review of medical records was analyzed for VLBWIs admitted to the neonatal intensive care unit of Samsung Medical Center within three days from birth. We compared the outcomes of previous corresponding data(period I : Oct. 1994 to Sept. 1996), with the outcomes of period II(Oct. 1996 to Dec. 1998) and period III(Jan. 1999 to Dec. 2000).
RESULTS: As shown in Tables 1 and 3, the distribution of birth weight, gestational age(GA), gender, and inborn admissions did not change during the 7-year study. The overall survival rate of VLBWI increased significantly over time(period I : 72% vs period III : 88.3%, P<0.05). Between period I and period II, the birth weight-specific survival rate increased by 23.6%(75% vs 92.7%, P<0.05) for infants 1,000 to 1,249 gm. Between period II and period III, the birth weight-specific survival rate increased three times(20% vs 66.7%, P<0.05) for infants <750 gm. The survivors of lowest birth weight included infants at 624 gm(GA : 26(+5) weeks), 667 gm(GA : 25(+6) weeks) and 480 gm(GA : 26(+2) weeks) in each period. The gestational age-specific survival rate in period III increased significantly in GA 25-26 weeks and 29-30 weeks(vs period I and period II, P<0.05). The survivors of lowest gestational age included infants at GA 26 weeks(970 gm), GA 23(+5) weeks(791 gm) and GA 24(+1) weeks(740 gm) in each period. The incidence of severe IVH(grade III, IV) and the early death rate(