title: Progesterone supplementation for preventing preterm birth: a systematic review and meta-analysis.
abstract: OBJECTIVE
  The aim of this study is to assess the role of progesterone in preterm birth prevention.
  
  
  METHODS
  A MEDLINE search (from 1966 to the present; date of last search January 2005) was performed - using the key words progesterone, pregnancy, preterm birth, preterm labor, and randomized, controlled trial - in order to identify randomized, controlled trials in which progesterone (either intramuscular or vaginal administration) was compared with placebo or no treatment. Data were extracted and a meta-analysis was performed.
  
  
  RESULTS
  Seven randomized, controlled trials were identified. Women who received progesterone were statistically significantly less likely to give birth before 37 weeks (seven studies, 1020 women, RR = 0.58, 95% CI = 0.48-0.70), to have an infant with birth weight of < or =2.5 kg (six studies, 872 infants, RR = 0.62, 95% CI = 0.49-0.78), or to have an infant diagnosed with intraventricular hemorrhage (one study, 458 infants, RR = 0.25, 95% CI = 0.08-0.82).
  
  
  CONCLUSIONS
  For progesterone supplementation to be advocated for women at the risk of preterm birth, the prolongation of gestation demonstrated in this meta-analysis must translate into improved infant outcomes, including a reduction in mortality. There is currently insufficient information to allow recommendations regarding the optimal dose, route, and timing of administration of progesterone supplementation.
authors.affiliation: Department of Obstetrics and Gynaecology, The University of Adelaide, Australia. jodie.dodd@adelaide.edu.au
authors.forename: Jodie M
authors.initials: JM
authors.lastname: Dodd
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Crowther
authors.forename: Robert
authors.initials: R
authors.lastname: Cincotta
authors.forename: Vicki
authors.initials: V
authors.lastname: Flenady
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Robinson
mesh_terms: D000282:Administration, Intravaginal; D001724:Birth Weight; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007752:Obstetric Labor, Premature / Q000517:prevention & control*; D011247:Pregnancy; D011374:Progesterone / Q000008:administration & dosage*; D016032:Randomized Controlled Trials as Topic; D015149:Tocolytic Agents / Q000008:administration & dosage*
chemical_list: D015149:Tocolytic Agents; D011374:Progesterone