Newborn intensive care and neonatal mortality in low-birth-weight infants: a population study.

We examined the neonatal mortality rates of low-birth-weight infants (501 to 2250 g) born between 1976 and 1978 in three kinds of hospitals in New York City: those with newborn-intensive-care units (Level 3), those with capabilities for the care of most premature infants (Level 2), and those without any special facilities for premature newborns (Level 1). Among 13,560 singleton low-birth-weight infants, the adjusted neonatal mortality rate for Level 3 hospitals was 128.5 per thousand live births - significantly lower (P less than 0.001) than the rates for both level 2 (168.1) and Level 1 units (163.0). The association of level of care with mortality could not be accounted for by differences between groups in social or demographic status, in prenatal care, or in medical complication of pregnancy. We infer that birth at a Level 3 center lowers neonatal mortality in low-birth-weight infants. However, only 34 per cent of the patients in this study were born in such units.