title: Balancing the efficacy and safety of misoprostol: a meta-analysis comparing 25 versus 50 micrograms of intravaginal misoprostol for the induction of labour.
abstract: BACKGROUND
  The optimal dose of misoprostol for the induction of labour remains uncertain.
  
  
  OBJECTIVE
  To compare the efficacy and safety of 25 versus 50 micrograms of intravaginal misoprostol tablets for the induction of labour and cervical ripening.
  
  
  METHODS
  We performed electronic and manual searches to identify relevant randomised trials.
  
  
  METHODS
  The efficacy outcomes assessed were rates of vaginal delivery within 24 hours, delivery within one dose, and oxytocin augmentation, and interval to delivery. The safety outcomes assessed were incidences of tachysystole, hyperstimulation, caesarean delivery, cesarean delivery for non-reassuring fetal heart rate (FHR), operative vaginal delivery, abnormal 5-minute Apgar score, abnormal cord gas values, admission to a neonatal intensive care unit (NICU), and meconium passage.
  
  
  METHODS
  Thirteen studies (1945 women) were included. Relative risk (RR) and 95% confidence intervals (CI) were calculated using fixed-effects and random-effects models.
  
  
  RESULTS
  We found that 25 micrograms was less efficacious, with lower rates of delivery after one dose (RR 0.59; 95% CI 0.39-0.88) and vaginal delivery within 24 hours (RR 0.88; 95% CI 0.79-0.96), and with increased rates of oxytocin augmentation (RR 1.54, 95% CI 1.36-1.75). We noted an improved safety profile with 25 micrograms, however, with decreased rates of tachysystole (RR 0.46; 95% CI 0.35-0.61), hyperstimulation (RR 0.5; 95% CI 0.31-0.78), caesarean deliveries for non-reassuring FHR (RR 0.67; 95% CI 0.52-0.87), NICU admissions (RR 0.63; 95% CI 0.4-0.98), and meconium passage (RR 0.65; 95% CI 0.45-0.96).
  
  
  CONCLUSIONS
  Although 50 micrograms of intravaginal misoprostol may be more efficacious, safety concerns make the 25-microgram dose preferable.
authors.affiliation: Department of Obstetrics and Gynecology, University of Florida College of Medicine - Jacksonville, Jacksonville, Florida, USA.
authors.forename: K
authors.initials: K
authors.lastname: McMaster
authors.forename: L
authors.initials: L
authors.lastname: Sanchez-Ramos
authors.forename: A M
authors.initials: AM
authors.lastname: Kaunitz
mesh_terms: D000282:Administration, Intravaginal; D000328:Adult; D020070:Cervical Ripening / Q000187:drug effects*; D036861:Delivery, Obstetric / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007751:Labor, Induced / Q000379:methods*; D016595:Misoprostol / Q000008:administration & dosage*; D010120:Oxytocics / Q000008:administration & dosage*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011263:Pregnancy Trimester, Third; D016032:Randomized Controlled Trials as Topic; D012306:Risk
chemical_list: D010120:Oxytocics; D016595:Misoprostol
keywords: Cervical ripening; induction of labour; misoprostol