title: Prevention of recurrent preterm delivery by 17 alpha-hydroxyprogesterone caproate.
abstract: BACKGROUND
  Women who have had a spontaneous preterm delivery are at greatly increased risk for preterm delivery in subsequent pregnancies. The results of several small trials have suggested that 17 alpha-hydroxyprogesterone caproate (17P) may reduce the risk of preterm delivery.
  
  
  METHODS
  We conducted a double-blind, placebo-controlled trial involving pregnant women with a documented history of spontaneous preterm delivery. Women were enrolled at 19 clinical centers at 16 to 20 weeks of gestation and randomly assigned by a central data center, in a 2:1 ratio, to receive either weekly injections of 250 mg of 17P or weekly injections of an inert oil placebo; injections were continued until delivery or to 36 weeks of gestation. The primary outcome was preterm delivery before 37 weeks of gestation. Analysis was performed according to the intention-to-treat principle.
  
  
  RESULTS
  Base-line characteristics of the 310 women in the progesterone group and the 153 women in the placebo group were similar. Treatment with 17P significantly reduced the risk of delivery at less than 37 weeks of gestation (incidence, 36.3 percent in the progesterone group vs. 54.9 percent in the placebo group; relative risk, 0.66 [95 percent confidence interval, 0.54 to 0.81]), delivery at less than 35 weeks of gestation (incidence, 20.6 percent vs. 30.7 percent; relative risk, 0.67 [95 percent confidence interval, 0.48 to 0.93]), and delivery at less than 32 weeks of gestation (11.4 percent vs. 19.6 percent; relative risk, 0.58 [95 percent confidence interval, 0.37 to 0.91]). Infants of women treated with 17P had significantly lower rates of necrotizing enterocolitis, intraventricular hemorrhage, and need for supplemental oxygen.
  
  
  CONCLUSIONS
  Weekly injections of 17P resulted in a substantial reduction in the rate of recurrent preterm delivery among women who were at particularly high risk for preterm delivery and reduced the likelihood of several complications in their infants.
authors.affiliation: Department of Obstetrics and Gynecology, Wake Forest University, Winston-Salem, NC 27157, USA. pmeis@wfubmc.edu
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Meis
authors.forename: Mark
authors.initials: M
authors.lastname: Klebanoff
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Thom
authors.forename: Mitchell P
authors.initials: MP
authors.lastname: Dombrowski
authors.forename: Baha
authors.initials: B
authors.lastname: Sibai
authors.forename: Atef H
authors.initials: AH
authors.lastname: Moawad
authors.forename: Catherine Y
authors.initials: CY
authors.lastname: Spong
authors.forename: John C
authors.initials: JC
authors.lastname: Hauth
authors.forename: Menachem
authors.initials: M
authors.lastname: Miodovnik
authors.forename: Michael W
authors.initials: MW
authors.lastname: Varner
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Leveno
authors.forename: Steve N
authors.initials: SN
authors.lastname: Caritis
authors.forename: Jay D
authors.initials: JD
authors.lastname: Iams
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Wapner
authors.forename: Deborah
authors.initials: D
authors.lastname: Conway
authors.forename: Mary J
authors.initials: MJ
authors.lastname: O'Sullivan
authors.forename: Marshall
authors.initials: M
authors.lastname: Carpenter
authors.forename: Brian
authors.initials: B
authors.lastname: Mercer
authors.forename: Susan M
authors.initials: SM
authors.lastname: Ramin
authors.forename: John M
authors.initials: JM
authors.lastname: Thorp
authors.forename: Alan M
authors.initials: AM
authors.lastname: Peaceman
authors.forename: Steven
authors.initials: S
authors.lastname: Gabbe
mesh_terms: D000077713:17 alpha-Hydroxyprogesterone Caproate; D000328:Adult; D001724:Birth Weight; D002543:Cerebral Hemorrhage / Q000453:epidemiology; D004311:Double-Blind Method; D020345:Enterocolitis, Necrotizing / Q000453:epidemiology; D005260:Female; D006801:Humans; D006908:Hydroxyprogesterones / Q000009:adverse effects / Q000627:therapeutic use*; D007231:Infant, Newborn; D007234:Infant, Premature; D007752:Obstetric Labor, Premature / Q000517:prevention & control*; D010102:Oxygen Inhalation Therapy; D011247:Pregnancy; D011256:Pregnancy Outcome; D045167:Progesterone Congeners / Q000009:adverse effects / Q000627:therapeutic use*; D012306:Risk; D016019:Survival Analysis
chemical_list: D006908:Hydroxyprogesterones; D045167:Progesterone Congeners; D000077713:17 alpha-Hydroxyprogesterone Caproate