title: Neonatal morbidity according to gestational age and birth weight from five tertiary care centers in the United States, 1983 through 1986.
abstract: OBJECTIVE
  This study details the incidence, by gestational age and birth weight, of specific neonatal morbidities in singleton neonates without major congenital anomalies.
  
  
  METHODS
  Data were prospectively collected on all deliveries at five tertiary centers in the United States during the years 1983 through 1986. Pregnancies were meticulously dated and the gestational ages of the neonates at delivery were confirmed by Dubowitz score.
  
  
  RESULTS
  The incidence of respiratory distress syndrome gradually decreases with increasing gestational age until 36 weeks. A marked decrease in the incidence of necrotizing enterocolitis, patent ductus arteriosus, intraventricular hemorrhage, and sepsis occurs after 32 completed weeks. The number of days of mechanical ventilation for respiratory distress syndrome and newborn stay in the tertiary care facility also were significantly reduced after 32 weeks.
  
  
  CONCLUSIONS
  The incidence of both respiratory distress syndrome and patent ductus arteriosus is markedly decreased by both increasing gestational age and birth weight. The incidence of grade III and IV intraventricular hemorrhage, necrotizing enterocolitis, and sepsis virtually vanishes after 34 weeks. These data relating neonatal morbidities to gestational age are important to the obstetrician in the critical decision regarding the timing of delivery and to the parents, who can benefit from a realistic prediction of the neonatal course.
authors.affiliation: Department of Obstetrics, Gynecology and Reproductive Sciences, University of California Medical Center, San Francisco 94143-0346.
authors.forename: P A
authors.initials: PA
authors.lastname: Robertson
authors.forename: S H
authors.initials: SH
authors.lastname: Sniderman
authors.forename: R K
authors.initials: RK
authors.lastname: Laros
authors.forename: R
authors.initials: R
authors.lastname: Cowan
authors.forename: D
authors.initials: D
authors.lastname: Heilbron
authors.forename: R L
authors.initials: RL
authors.lastname: Goldenberg
authors.forename: J D
authors.initials: JD
authors.lastname: Iams
authors.forename: R K
authors.initials: RK
authors.lastname: Creasy
mesh_terms: D000046:Academic Medical Centers; D001724:Birth Weight; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000453:epidemiology* / Q000208:ethnology; D008423:Maternal Age; D009017:Morbidity; D044469:Racial Groups; D012727:Sex Characteristics; D014481:United States