title: Maintenance therapy with calcium channel blockers for preventing preterm birth after threatened preterm labour.
abstract: BACKGROUND
  Calcium channel blocker maintenance therapy is one of the types of tocolytic therapy used after an episode of threatened preterm labour (and usually an initial dose of tocolytic therapy) in an attempt to prevent the onset of further preterm contractions.
  
  
  OBJECTIVE
  To assess the effects of calcium channel blockers as maintenance therapy on preventing preterm birth after threatened preterm labour.
  
  
  METHODS
  We searched the Cochrane Pregnancy and Childbirth Group trials register (31 March 2004); MEDLINE (1966 to March 2004) and DARE (June 2003).
  
  
  METHODS
  Randomised controlled trials of calcium channel blockers used as maintenance therapy to prevent preterm birth after threatened preterm labour, compared with alternative drug therapy, placebo or no treatment.
  
  
  METHODS
  Two reviewers independently applied the selection criteria, extracted data from the included study and assessed study quality.
  
  
  RESULTS
  One trial of 74 women was included. No difference in the incidence of preterm birth was found when calcium channel blocker (nifedipine) maintenance therapy was compared with no treatment. Twenty-five women out of 37 in each group gave birth before 37 weeks (relative risk 1.00, 95% confidence interval 0.73 to 1.37). The trial did not report stillbirths and neonatal deaths prior to discharge. Neurological follow up of the infants was not addressed.
  
  
  CONCLUSIONS
  The role of maintenance therapy with calcium channel blockers for preventing preterm birth is not clear. Well designed randomised trials of sufficient size with relevant outcomes are required.
authors.forename: N N
authors.initials: NN
authors.lastname: Gaunekar
authors.forename: C A
authors.initials: CA
authors.lastname: Crowther
mesh_terms: D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D009543:Nifedipine / Q000627:therapeutic use; D007752:Obstetric Labor, Premature / Q000150:complications*; D011247:Pregnancy; D047928:Premature Birth / Q000517:prevention & control*
chemical_list: D002121:Calcium Channel Blockers; D009543:Nifedipine