title: Recent changes in delivery site of low-birth-weight infants in Washington: impact on birth weight-specific mortality.
abstract: OBJECTIVE
  Our purpose was to ascertain whether the proportion of low-birth-weight infants delivered in Washington at tertiary hospitals changed between 1980 and 1991 and whether mortality differed by level of birth hospital.
  
  
  METHODS
  A retrospective cohort study was performed of 500 to 2499 gm infants born to Washington residents between 1980 and 1991 (n = 43,228).
  
  
  RESULTS
  Overall, the percentage of low-birth-weight infants born at tertiary centers rose from 1980 to 1982 through 1986 to 1988 and subsequently declined significantly. Among infants weighing < 2000 gm nontertiary delivery was associated with greater potentially preventable mortality (500 to 999 gm, relative risk 1.5, 95% confidence interval 1.3 to 1.8; 1000 to 1499 gm, relative risk 2.1, 95% confidence interval 1.3 to 3.3; 1500 to 1999 gm, relative risk 1.6, 95% confidence interval 1.0 to 2.6). Nontertiary delivery of 2000 to 2499 gm infants was associated with lower overall mortality (relative risk 0.5, 95% confidence interval 0.3 to 0.8), but higher-risk deliveries in this birth weight range were apparently concentrated at tertiary hospitals.
  
  
  CONCLUSIONS
  In light of the apparent benefit of tertiary center birth for infants weighing < 2000 gm, the possible erosion of effective regionalized perinatal care networks should be monitored closely.
authors.affiliation: Maternal and Child Health Program, School of Public Health and Community Medicine, University of Washington, Seattle 98195, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: Powell
authors.forename: V L
authors.initials: VL
authors.lastname: Holt
authors.forename: D E
authors.initials: DE
authors.lastname: Hickok
authors.forename: T
authors.initials: T
authors.lastname: Easterling
authors.forename: F A
authors.initials: FA
authors.lastname: Connell
mesh_terms: D000328:Adult; D001724:Birth Weight; D015331:Cohort Studies; D016001:Confidence Intervals; D036861:Delivery, Obstetric; D005260:Female; D006801:Humans; D007226:Infant Mortality; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008423:Maternal Age; D010298:Parity; D011247:Pregnancy; D011295:Prenatal Care; D012189:Retrospective Studies; D012307:Risk Factors; D012959:Socioeconomic Factors; D014861:Washington