Atosiban trial protocol aims to improve live birth rates for women with implantation failure.

For women undergoing assisted reproductive technology (ART), embryo implantation failure remains a significant challenge, often leading to emotional distress and repeated cycles. Current standard-of-care protocols do not consistently address the issue of abnormal uterine contractions, which can hinder successful implantation. Atosiban, an oxytocin receptor antagonist, has shown promise in specific subpopulations by potentially reducing these contractions. Previous Phase I data suggested a trend towards improved live birth rates in women with prior implantation failure and abnormal uterine contractions, but lacked statistical significance. This protocol aims to definitively assess atosiban's efficacy and validate uterine contractions as a predictive biomarker.

This is a single-centre, randomised, triple-blind, placebo-controlled trial protocol designed to enroll 792 infertile women aged 20-40 years. Participants must have a history of at least one previous embryo implantation failure and exhibit abnormal uterine contractions prior to single blastocyst-stage embryo transfer. Eligible women will be randomly assigned in a 1:1 ratio to receive either intravenous atosiban or a placebo before embryo transfer. Randomisation will be stratified by age and transfer type. The primary outcome is live birth rate, with secondary outcomes encompassing various pregnancy and perinatal parameters. An independent data and safety monitoring committee will oversee the trial, including one interim analysis.

As a study protocol, this paper presents no experimental results. However, it outlines the primary outcome the trial aims to measure: the live birth rate. The study is designed to thoroughly elucidate the efficacy of atosiban and to evaluate whether uterine contractions can serve as a reliable biomarker for its targeted application. This large-scale investigation builds upon previous Phase I data, which indicated potential improvements in live birth rates among women with previous implantation failure undergoing frozen-thawed blastocyst transfer who exhibited abnormal uterine contractions, although these initial findings did not reach statistical significance. The trial will conduct intention-to-treat analysis using generalised linear models to assess atosiban's impact.

The primary outcome of this trial is the live birth rate following single blastocyst-stage embryo transfer.