The purpose of this study was to see how efficient acute nifedipine tocolysis was at preventing premature delivery in women in preterm labour. This was a randomised, double-blind, placebo-controlled study of nifedipine in women with a singleton pregnancy who were hospitalised with uterine activity, intact membranes, and cervical dilatation of 2 to 4 cm. Women were randomly assigned to receive nifedipine 20 mg or placebo orally, with a repeat dose administered after 90 minutes if contractions continued. The research medication was given every 4 hours for a total of 48 hours. The major goal was to have a baby before 37 weeks of pregnancy. It took a total of 150 women to identify a one-third reduction in this result. After treating 88 patients, the Data Safety Monitoring Committee advised that the study be terminated owing to futility, based on a preplanned interim review of blinded results. Between May 2014 and November 2017, 90 women were enrolled. Following the withdrawal of two women, 88 women were studied: 46 in the nifedipine group and 42 in the placebo group. There was no significant difference between the nifedipine and placebo groups in the primary outcome of delivery before 37 weeks of gestation, nor in the secondary outcome of delivery at least 48 hours after randomization.

Acute nifedipine tocolysis of preterm labour had no effect on preterm birth rates, delivery within 48 hours, or neonatal outcomes.