title: Outcomes of infants born at 22 and 23 weeks' gestation.
abstract: OBJECTIVE
  To provide instructive information on death and neurodevelopmental outcomes of infants born at 22 and 23 weeks' gestational age.
  
  
  METHODS
  The study cohort consisted of 1057 infants born at 22 to 25 weeks in the Neonatal Research Network, Japan. Neurodevelopmental impairment (NDI) at 36 to 42 months' chronological age was defined as any of the following: cerebral palsy, hearing impairment, visual impairment, and a developmental quotient <70. A systematic review was performed by using databases of publications of cohort studies with neonatal and neurodevelopmental outcomes at 22 and 23 weeks.
  
  
  RESULTS
  Numbers and incidences (%) of infants with death or NDI were 60 (80%) at 22 weeks and 156 (64%) at 23 weeks. In logistic regression analysis, gestational ages of 22 weeks (odds ratio [OR]: 5.40; 95% confidence interval [CI]: 2.48-11.76) and 23 weeks (OR: 2.14; 95% CI: 1.38-3.32) were associated with increased risk of death or NDI compared with 24 weeks, but a gestational age of 25 weeks (OR: 0.65; 95% CI: 0.45-0.95) was associated with decreased risk of death or NDI. In the systematic review, the medians (range) of the incidence of death or NDI in 8 cohorts were 99% (90%-100%) at 22 weeks and 98% (67%-100%) at 23 weeks.
  
  
  CONCLUSIONS
  Infants born at 22 and 23 weeks' gestation were at higher risk of death or NDI than infants at born at 24 weeks. However, outcomes were improved compared with those in previous studies. There is a need for additional discussions on interventions for infants born at 22 or 23 weeks' gestation.
authors.affiliation: Department of Pediatrics, Aiiku Hospital, Minato, Tokyo, Japan.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Ishii
authors.forename: Yumi
authors.initials: Y
authors.lastname: Kono
authors.forename: Naohiro
authors.initials: N
authors.lastname: Yonemoto
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kusuda
authors.forename: Masanori
authors.initials: M
authors.lastname: Fujimura
mesh_terms: D002423:Cause of Death; D002547:Cerebral Palsy / Q000175:diagnosis* / Q000401:mortality*; D002658:Developmental Disabilities / Q000175:diagnosis* / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D034381:Hearing Loss / Q000175:diagnosis* / Q000401:mortality*; D017052:Hospital Mortality; D006801:Humans; D052577:Infant, Extremely Low Birth Weight; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000175:diagnosis* / Q000401:mortality*; D007564:Japan; D008297:Male; D012044:Regression Analysis; D062606:Tertiary Care Centers / Q000706:statistics & numerical data; D014786:Vision Disorders / Q000175:diagnosis* / Q000401:mortality*
keywords: cerebral palsy; cognitive impairment; extremely preterm infants; neurodevelopmental; outcome of high-risk infants