title: Prophylactic administration of progesterone by vaginal suppository to reduce the incidence of spontaneous preterm birth in women at increased risk: a randomized placebo-controlled double-blind study.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effect of prophylactic vaginal progesterone in decreasing preterm birth rate in a high-risk population.
  
  
  METHODS
  A randomized, double-blind, placebo-controlled study included 142 high-risk singleton pregnancies. Progesterone (100 mg) or placebo was administered daily by vaginal suppository and all patients underwent uterine contraction monitoring with an external tocodynamometer once a week for 60 minutes, between 24 and 34 weeks of gestation. Progesterone (n = 72) and placebo (n = 70) groups were compared for epidemiologic characteristics, uterine contraction frequency, and incidence of preterm birth. Data were compared by chi(2) analysis and Fisher exact test.
  
  
  RESULTS
  The preterm birth rate was 21.1% (30/142). Differences in uterine activity were found between the progesterone and placebo groups (23.6% vs 54.3%, respectively; P <.05) and in preterm birth between progesterone and placebo (13.8% vs 28.5%, respectively; P <.05). More women were delivered before 34 weeks in the placebo group (18.5%) than in the progesterone group (2.7%) (P <.05).
  
  
  CONCLUSIONS
  Prophylactic vaginal progesterone reduced the frequency of uterine contractions and the rate of preterm delivery in women at high risk for prematurity.
authors.affiliation: Obstetrics Clinic, University of São Paulo Medical School, Brazil. riedu@uol.com.br
authors.forename: Eduardo B
authors.initials: EB
authors.lastname: da Fonseca
authors.forename: Roberto E
authors.initials: RE
authors.lastname: Bittar
authors.forename: Mario H B
authors.initials: MH
authors.lastname: Carvalho
authors.forename: Marcelo
authors.initials: M
authors.lastname: Zugaib
mesh_terms: D000328:Adult; D001723:Birth Rate; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007752:Obstetric Labor, Premature / Q000517:prevention & control*; D010919:Placebos / Q000627:therapeutic use; D011247:Pregnancy; D011374:Progesterone / Q000008:administration & dosage*; D012307:Risk Factors; D013488:Suppositories; D014590:Uterine Contraction / Q000187:drug effects
chemical_list: D010919:Placebos; D013488:Suppositories; D011374:Progesterone