title: Atosiban versus fenoterol as a uterine relaxant for external cephalic version: randomised controlled trial.
abstract: OBJECTIVE
  To compare the effectiveness of the oxytocin receptor antagonist atosiban with the beta mimetic fenoterol as uterine relaxants in women undergoing external cephalic version (ECV) for breech presentation.
  
  
  METHODS
  Multicentre, open label, randomised controlled trial.
  
  
  METHODS
  Eight hospitals in the Netherlands, August 2009 to May 2014.
  
  
  METHODS
  830 women with a singleton fetus in breech presentation and a gestational age of more than 34 weeks were randomly allocated in a 1:1 ratio to either 6.75 mg atosiban (n=416) or 40 μg fenoterol (n=414) intravenously for uterine relaxation before ECV.
  
  
  METHODS
  The primary outcome measures were a fetus in cephalic position 30 minutes after the procedure and cephalic presentation at delivery. Secondary outcome measures were mode of delivery, incidence of fetal and maternal complications, and drug related adverse events. All analyses were done on an intention-to-treat basis.
  
  
  RESULTS
  Cephalic position 30 minutes after ECV occurred significantly less in the atosiban group than in the fenoterol group (34% v 40%, relative risk 0.73, 95% confidence interval 0.55 to 0.93). Presentation at birth was cephalic in 35% (n=139) of the atosiban group and 40% (n=166) of the fenoterol group (0.86, 0.72 to 1.03), and caesarean delivery was performed in 60% (n=240) of women in the atosiban group and 55% (n=218) in the fenoterol group (1.09, 0.96 to 1.20). No significant differences were found in neonatal outcomes or drug related adverse events.
  
  
  CONCLUSIONS
  In women undergoing ECV for breech presentation, uterine relaxation with fenoterol increases the rate of cephalic presentation 30 minutes after the procedure. No statistically significant difference was found for cephalic presentation at delivery.
  
  
  BACKGROUND
  Dutch Trial Register, NTR 1877.
authors.affiliation: Department of Obstetrics and Gynaecology, Academic Medical Centre, Amsterdam, Netherlands j.velzel@amc.nl.
authors.forename: Joost
authors.initials: J
authors.lastname: Velzel
authors.affiliation: Department of Obstetrics and Gynaecology, Academic Medical Centre, Amsterdam, Netherlands.
authors.forename: Floortje
authors.initials: F
authors.lastname: Vlemmix
authors.affiliation: Clinical Research Unit, Academic Medical Centre, Amsterdam, Netherlands.
authors.forename: Brent C
authors.initials: BC
authors.lastname: Opmeer
authors.affiliation: Department of Obstetrics and Gynaecology, Spaarne Gasthuis, Hoofddorp, Netherlands.
authors.forename: Jan F M
authors.initials: JF
authors.lastname: Molkenboer
authors.affiliation: Department of Obstetrics and Gynaecology, Maxima Medical Centre, Veldhoven, Netherlands.
authors.forename: Corine J
authors.initials: CJ
authors.lastname: Verhoeven
authors.affiliation: Department of Obstetrics and Gynaecology, Onze Lieve Vrouwe Gasthuis, Amsterdam, Netherlands.
authors.forename: Mariëlle G
authors.initials: MG
authors.lastname: van Pampus
authors.affiliation: Department of Obstetrics and Gynaecology, Amphia Hospital, Breda, Netherlands.
authors.forename: Dimitri N M
authors.initials: DN
authors.lastname: Papatsonis
authors.affiliation: Department of Obstetrics and Gynaecology, Medical Centre Alkmaar, Alkmaar, Netherlands.
authors.forename: Joke M J
authors.initials: JM
authors.lastname: Bais
authors.affiliation: Department of Obstetrics and Gynaecology, Spaarne Gasthuis, Haarlem, Netherlands.
authors.forename: Karlijn C
authors.initials: KC
authors.lastname: Vollebregt
authors.affiliation: Department of Obstetrics and Gynaecology, St Antonius Hospital, Nieuwegein, Netherlands.
authors.forename: Liesbeth
authors.initials: L
authors.lastname: van der Esch
authors.affiliation: Department of Obstetrics and Gynaecology, Academic Medical Centre, Amsterdam, Netherlands.
authors.forename: Joris A M
authors.initials: JA
authors.lastname: Van der Post
authors.affiliation: Robinson Institute, School of Paediatrics and Reproductive Health, University of Adelaide.|South Australian Health and Medical Research Institute, Adelaide, Australia.
authors.forename: Ben Willem
authors.initials: BW
authors.lastname: Mol
authors.affiliation: Department of Obstetrics and Gynaecology, Academic Medical Centre, Amsterdam, Netherlands.
authors.forename: Marjolein
authors.initials: M
authors.lastname: Kok
mesh_terms: D000328:Adult; D001946:Breech Presentation; D002585:Cesarean Section; D005260:Female; D005280:Fenoterol / Q000627:therapeutic use*; D006801:Humans; D009426:Netherlands; D011247:Pregnancy; D011256:Pregnancy Outcome; D015149:Tocolytic Agents / Q000627:therapeutic use*; D014668:Vasotocin / Q000031:analogs & derivatives* / Q000627:therapeutic use; D014710:Version, Fetal / Q000379:methods*
chemical_list: D015149:Tocolytic Agents; C047046:atosiban; D005280:Fenoterol; D014668:Vasotocin