title: Prophylaxis with 17 alpha-hydroxyprogesterone caproate for prevention of recurrent preterm delivery: does gestational age at initiation of treatment matter?
abstract: OBJECTIVE
  The purpose of this study was to determine effectiveness of 17 alpha-hydroxyprogesterone caproate (17 P) prophylaxis by gestational age (GA) at 17 P initiation.
  
  
  METHODS
  Singleton gestations with > or = 1 preterm birth (PTB) treated with 17 P prophylaxis for recurrent preterm birth before 27 weeks were identified from a data base. Data were stratified by GA at 17 P initiation (16-20.9 [n = 599] weeks and 21-26.9 [n = 307] weeks) and number of PTB (1, 2, > 2). Outcome variables were PTB at < 37, < 35, and < 32 weeks.
  
  
  RESULTS
  No significant differences were found in gestational age at delivery or rates of recurrent PTB < 37, < 35, and < 32 weeks between those women initiating 17 P at 16-20.9 weeks or 21-26.9 weeks, or when stratified by number of prior preterm deliveries.
  
  
  CONCLUSIONS
  Initiation of 17 P prophylaxis at 21-26.9 weeks is as effective as initiation at 16-20.9 weeks of gestation.
authors.affiliation: Department of Obstetrics and Gynecology, University of Cincinnati, Cincinnati, OH, USA.
authors.forename: Helen Y
authors.initials: HY
authors.lastname: How
authors.forename: John R
authors.initials: JR
authors.lastname: Barton
authors.forename: Niki B
authors.initials: NB
authors.lastname: Istwan
authors.forename: Debbie J
authors.initials: DJ
authors.lastname: Rhea
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Stanziano
mesh_terms: D000077713:17 alpha-Hydroxyprogesterone Caproate; D000293:Adolescent; D000328:Adult; D005260:Female; D005865:Gestational Age; D006801:Humans; D006908:Hydroxyprogesterones / Q000627:therapeutic use*; D007752:Obstetric Labor, Premature / Q000517:prevention & control*; D011247:Pregnancy; D047928:Premature Birth / Q000517:prevention & control*; D012008:Recurrence; D012189:Retrospective Studies; D015149:Tocolytic Agents / Q000627:therapeutic use*; D016896:Treatment Outcome