ABSTRACT
OBJECTIVE: To evaluate the efficacy and safety of early administration compared with standard administration of atosiban, when predefined eligibility criteria were met. DESIGN: A prospective, open-label, randomised clinical trial. Women were randomised to receive atosiban either immediately (early) or when specified criteria, in terms of duration/frequency of uterine contraction or status of cervical dilation/effacement, were fulfilled (standard). SETTING: Carried out at 105 centres in six European countries. POPULATION: Pregnant women admitted to hospital in threatened preterm labour between 24 and 34 weeks of gestation, comprising a subgroup of women enrolled in the Tractocile Efficacy Assessment Survey in Europe (TREASURE) clinical experience review. MAIN OUTCOME MEASURES: Efficacy was defined as the successful delay of delivery with no alternative tocolytic agent for 48 hours. RESULTS: More women in the early group remained undelivered at 48 hours with no alternative tocolytic agent compared with those who received atosiban when specified criteria were fulfilled (88.9 versus 76.1%; P = 0.03). Safety was comparable between the groups. There were no statistical differences in maternal, fetal or neonatal adverse events between the early and standard atosiban arms. CONCLUSIONS: The use of atosiban was effective for the delay of preterm labour and presented no safety concerns irrespective of the time it was administered.