title: Antenatal corticosteroids promote survival of extremely preterm infants born at 22 to 23 weeks of gestation.
abstract: OBJECTIVE
  To evaluate the effectiveness of antenatal corticosteroid (ACS) to improve neonatal outcomes for infants born at <24 weeks of gestation.
  
  
  METHODS
  We performed a retrospective analysis of 11,607 infants born at 22 to 33 weeks of gestation between 2003 and 2007 from the Neonatal Research Network of Japan. We evaluated the gestational age effects of ACS administered to mothers with threatened preterm birth on several factors related to neonatal morbidity and mortality.
  
  
  RESULTS
  By logistic regression analysis, ACS exposure decreased respiratory distress syndrome and severe intraventricular hemorrhage in infants born between 24 and 29 weeks of gestation. Cox regression analysis revealed that ACS exposure was associated with a significant decrease in mortality of preterm infants born at 22 or 23 weeks of gestation (adjusted hazard ratio, 0.72; 95% CI, 0.53 to 0.97; P=.03). This effect was also observed at 24 to 25 and 26 to 27 weeks of gestation and in the overall study population.
  
  
  CONCLUSIONS
  ACS exposure improved survival of extremely preterm infants. ACS treatment should be considered for threatened preterm birth at 22 to 23 weeks of gestation.
authors.affiliation: Department of Global Health Policy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. rintaromori@gmail.com
authors.forename: Rintaro
authors.initials: R
authors.lastname: Mori
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kusuda
authors.forename: Masanori
authors.initials: M
authors.lastname: Fujimura
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D016022:Case-Control Studies; D002543:Cerebral Hemorrhage / Q000401:mortality* / Q000517:prevention & control; D004363:Drug Utilization; D004374:Ductus Arteriosus, Patent / Q000401:mortality; D020345:Enterocolitis, Necrotizing / Q000401:mortality; D005260:Female; D005865:Gestational Age; D017052:Hospital Mortality; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D007564:Japan / Q000453:epidemiology; D008297:Male; D015999:Multivariate Analysis; D010102:Oxygen Inhalation Therapy; D011247:Pregnancy; D047928:Premature Birth / Q000517:prevention & control; D011295:Prenatal Care; D011663:Pulmonary Surfactants / Q000627:therapeutic use; D012127:Respiratory Distress Syndrome, Newborn / Q000401:mortality* / Q000517:prevention & control; D012189:Retrospective Studies
chemical_list: D000305:Adrenal Cortex Hormones; D011663:Pulmonary Surfactants