title: Gestational age-specific risks vs benefits of multicourse antenatal corticosteroids for preterm labor.
abstract: OBJECTIVE
  The purpose of this study was to estimate a gestational age threshold at which the benefits of treatment with weekly courses of antenatal corticosteroids (ACS) during preterm labor outweigh the risks.
  
  
  METHODS
  Risk-benefit ratios by gestational age were determined with the use of a Markov microsimulation decision-analysis model with a 1-week cycle length. Single course and multiple (weekly to a maximum of 4) courses of ACS by gestational age of entry (23 weeks to 31 weeks 6 days' gestation) were compared. Benefits were composite events (respiratory distress syndrome, chronic lung disease, severe intraventricular hemorrhage, periventricular leukomalacia, bronchopulmonary dysplasia, or stillbirth) averted. Risks were small head circumference and small for gestational age.
  
  
  RESULTS
  More composite events are averted (benefits) than risks acquired (ratio, 6:1) when multiple courses of ACS are initiated at 26 weeks' gestation. When multiple courses of ACS are initiated at 29 weeks' gestation, the risk-benefit ratio is 1. Beyond 29 weeks, there is a suggestion of more risk than benefit.
  
  
  CONCLUSIONS
  The model suggests that multiple courses of ACS that are initiated at <29 weeks' gestation may have increased benefit compared with risks. Further analyses are needed to determine the long-term clinical significance of these findings.
authors.affiliation: Department of Obstetrics and Gynecology, College of Physicians and Surgeons, Columbia University, New York, NY. Electronic address: Laurie.Zephyrin@va.gov.
authors.forename: Laurie C
authors.initials: LC
authors.lastname: Zephyrin
authors.forename: Kimberly N
authors.initials: KN
authors.lastname: Hong
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Wapner
authors.forename: Alan M
authors.initials: AM
authors.lastname: Peaceman
authors.forename: Yoram
authors.initials: Y
authors.lastname: Sorokin
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Dudley
authors.forename: Jay D
authors.initials: JD
authors.lastname: Iams
authors.forename: Margaret
authors.initials: M
authors.lastname: Harper
authors.forename: Steve N
authors.initials: SN
authors.lastname: Caritis
authors.forename: Brian M
authors.initials: BM
authors.lastname: Mercer
authors.forename: John M
authors.initials: JM
authors.lastname: Thorp
authors.forename: Susan M
authors.initials: SM
authors.lastname: Ramin
authors.forename: Dwight J
authors.initials: DJ
authors.lastname: Rouse
authors.forename: Baha
authors.initials: B
authors.lastname: Sibai
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D003661:Decision Support Techniques; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000517:prevention & control*; D020300:Intracranial Hemorrhages / Q000517:prevention & control; D008390:Markov Chains; D009010:Monte Carlo Method; D007752:Obstetric Labor, Premature; D011247:Pregnancy; D012127:Respiratory Distress Syndrome, Newborn / Q000517:prevention & control; D018570:Risk Assessment
chemical_list: D000305:Adrenal Cortex Hormones
keywords: antenatal corticosteroid; decision analysis; preterm labor