title: Nifedipine versus atosiban in the treatment of threatened preterm labour (Assessment of Perinatal Outcome after Specific Tocolysis in Early Labour: APOSTEL III-Trial).
abstract: BACKGROUND
  Preterm birth is the most common cause of neonatal morbidity and mortality. Postponing delivery for 48 hours with tocolytics to allow for maternal steroid administration and antenatal transportation to a centre with neonatal intensive care unit facilities is the standard treatment for women with threatening preterm delivery in most centres. However, there is controversy as to which tocolytic agent is the drug of first choice. Previous trials have focused on tocolytic efficacy and side effects, and are probably underpowered to detect clinically meaningfull differences in neonatal outcome. Thus, the current evidence is inconclusive to support a balanced recommendation for clinical practice. This multicenter randomised clinical trial aims to compare nifedipine and atosiban in terms of neonatal outcome, duration of pregnancy and maternal side effects.
  
  
  METHODS
  The Apostel III trial is a nationwide multicenter randomised controlled study. Women with threatened preterm labour (gestational age 25 - 34 weeks) defined as at least 3 contractions per 30 minutes, and 1) a cervical length of ≤ 10 mm or 2) a cervical length of 11-30 mm and a positive Fibronectin test or 3) ruptured membranes will be randomly allocated to treatment with nifedipine or atosiban. Primary outcome is a composite measure of severe neonatal morbidity and mortality. Secondary outcomes will be time to delivery, gestational age at delivery, days on ventilation support, neonatal intensive care (NICU) admittance, length admission in neonatal intensive care, total days in hospital until 3 months corrected age, convulsions, apnoea, asphyxia, proven meningitis, pneumothorax, maternal side effects and costs. Furthermore, an economic evaluation of the treatment will be performed. Analysis will be by intention to treat principle. The power calculation is based on an expected 10% difference in the prevalence of adverse neonatal outcome. This implies that 500 women have to be randomised (two sided test, β 0.2 at alpha 0.05).
  
  
  CONCLUSIONS
  This trial will provide evidence on the optimal drug of choice in acute tocolysis in threatening preterm labour.
  
  
  BACKGROUND
  
  
  
  BACKGROUND
  NTR2947, date of registration: June 20th 2011.
authors.affiliation: Department of Obstetrics and Gynaecology, University Medical Centre Utrecht, Utrecht, the Netherlands. e.o.g.vanvliet@umcutrecht.nl.
authors.forename: Elvira Og
authors.initials: EO
authors.lastname: van Vliet
authors.forename: Ewoud
authors.initials: E
authors.lastname: Schuit
authors.forename: Karst Y
authors.initials: KY
authors.lastname: Heida
authors.forename: Brent C
authors.initials: BC
authors.lastname: Opmeer
authors.forename: Marjolein
authors.initials: M
authors.lastname: Kok
authors.forename: Wilfried
authors.initials: W
authors.lastname: Gyselaers
authors.forename: Martina M
authors.initials: MM
authors.lastname: Porath
authors.forename: Mallory
authors.initials: M
authors.lastname: Woiski
authors.forename: Caroline J
authors.initials: CJ
authors.lastname: Bax
authors.forename: Kitty Wm
authors.initials: KW
authors.lastname: Bloemenkamp
authors.forename: Hubertina Cj
authors.initials: HC
authors.lastname: Scheepers
authors.forename: Yves
authors.initials: Y
authors.lastname: Jaquemyn
authors.forename: Erik
authors.initials: E
authors.lastname: van Beek
authors.forename: Hans Jj
authors.initials: HJ
authors.lastname: Duvekot
authors.forename: Maureen Tm
authors.initials: MT
authors.lastname: Franssen
authors.forename: Bas N
authors.initials: BN
authors.lastname: Bijvank
authors.forename: Joke H
authors.initials: JH
authors.lastname: Kok
authors.forename: Arie
authors.initials: A
authors.lastname: Franx
authors.forename: Ben Willem J
authors.initials: BW
authors.lastname: Mol
authors.forename: Martijn A
authors.initials: MA
authors.lastname: Oudijk
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007226:Infant Mortality / Q000639:trends; D007231:Infant, Newborn; D007275:Injections, Intravenous; D008428:Maternal Mortality / Q000639:trends; D009426:Netherlands / Q000453:epidemiology; D009543:Nifedipine / Q000008:administration & dosage*; D007752:Obstetric Labor, Premature / Q000517:prevention & control*; D017063:Outcome Assessment, Health Care; D011247:Pregnancy; D011379:Prognosis; D015145:Tocolysis / Q000379:methods*; D015149:Tocolytic Agents / Q000008:administration & dosage; D014668:Vasotocin / Q000008:administration & dosage / Q000031:analogs & derivatives*; D055815:Young Adult
chemical_list: D015149:Tocolytic Agents; C047046:atosiban; D009543:Nifedipine; D014668:Vasotocin