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NCT Number: NCT07185230

Atosiban in Women With Previous Implantation Failure and Abnormal Uterine Contractions

This study aims to evaluate the efficacy of atosiban in patients with previous pregnancy failure and abnormal uterine contractions during the peri-embryo transfer period in assisted reproductive technology. The main questions it aims to answer are:

* Does the use of atosiban in patients with a history of implantation failure and abnormal uterine contractions affect the live birth rate in single blastocyst transfer cycles (fresh or frozen-thawed embryo transfer)? * Evaluate the differences in efficacy of atosiban regarding perinatal complications and neonatal outcomes, as well as differences in safety concerning miscarriage rates and ectopic pregnancy rates.

Researchers will compare atosiban with placebo (a similar substance containing no active medication) to determine whether atosiban is effective in improving live birth rates from single blastocyst transfer cycles (fresh or frozen-thawed embryo transfer) in patients with a history of implantation failure and abnormal uterine contractions.

* Participants allocated to the Atosiban group will be administered Atosiban (37.5 mg/5 mL, Tractocile®, Ferring Pharma, Geneva, Switzerland) as an intravenous (IV) bolus of 6·75 mg/0.9 mL in 1 minute at 30 minutes prior to the ET procedure, followed by an IV infusion at a rate of 18 mg/h for 1 hour; after 1 hour, the dose of Atosiban will be reduced to 6 mg/h, with a total dose of 37.5 mg. Participants allocated to the placebo group will receive identical-looking saline infusions for the same duration. * One hour post-embryo transfer, all randomized participants will be invited to have a reevaluation of uterine wave patterns via ultrasound, performed by the same examiner. * Women who had a clinical pregnancy will be subsequently contacted by nurses to document pregnancy events and outcomes at 12 and 24 weeks of gestation, completion of pregnancy, with a follow-up approximately 6 weeks post-delivery. Those participants who had a negative pregnancy test will not be followed up any further as part of this trial.

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Key information

Conditions

Infertility Genital Diseases Urogenital Diseases

Age range

20 year–40 year

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Primary location

Center for Reproductive Medicine, Northwest Women's and Children's Hospital

Xi'an, Shaanxi, 710003, China

Location status: Recruiting

Location contact

Juanzi Prof Shi, MD

CONTACT

[email protected]

+8613581613908

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Participants/eligibility criteria

Infertile women who fulfill all of the following inclusion criteria, based on the results and findings of the Atosiban 1 study are eligible for participation:

  • Scheduled for single blastocyst-stage embryo transfer, either in a fresh or frozen transfer cycle;
  • Have a history of one or more episodes of implantation failures in previous embryo transfer cycles;
  • Age between 20 and 40 years (inclusive);
  • Exhibit abnormal uterine peristalsis on transvaginal ultrasound performed on the morning of the scheduled blastocyst transfer, defined as either: high-frequency peristalsis (>4 contractions per minute), or a negative wave pattern (fundus-to-cervix direction) at any frequency.
  • Each woman could only participate in one transfer cycle.

Exclusion criteria

  • Immunologic or endocrine disorders including thyroid dysfunction, antiphospholipid syndrome, hyperprolactinemia and other severe systematic diseases (e.g., hypertension, diabetes, etc.)
  • Uterine malformations (e.g., intrauterine adhesions; unicornuate, bicornuate or septate uterus)；
  • Untreated hydrosalpinx or endometrial polyp；
  • Cycles that included in-vitro maturation or oocyte donation；
  • Prior participation in Atosiban 1 study；
  • Current participation in any other clinical trial；
  • Inability to provide informed consent to the study.

Treatment and study plan

Atosiban

Drug

Participants allocated to the Atosiban group will be administered Atosiban (37.5 mg/5 mL, Tractocile®, Ferring Pharma, Geneva, Switzerland) as an intravenous (IV) bolus of 6·75 mg/0.9 mL in 1 minute at 30 minutes prior to the ET procedure, followed by an IV infusion at a rate of 18 mg/h for 1 hour; after 1 hour, the dose of Atosiban will be reduced to 6 mg/h, with a total dose of 37.5 mg.

Placebo Control

Drug

Participants allocated to the placebo group will receive identical-looking saline infusions for the same duration.

Primary outcomes

  1. Live birth

    Time frame: After 24 weeks of gestation

    Live birth is defined as the delivery of at least one newborn who exhibits any sign of life.

Secondary outcomes

  1. Biochemical pregnancy

    Time frame: 12 days after blastocyst transfer

    Biochemical pregnancy is defined as serum beta-human chorionic gonadotropin β-hCG> 10 IU/L 12 days after blastocyst transfer.

  2. Clinical pregnancy

    Time frame: 6-8 weeks after blastocyst transfer.

    Clinical pregnancy is defined as observed gestational sac or definitive clinical signs of pregnancy observed at ultrasonography (including clinically documented ectopic pregnancy)

  3. Ongoing pregnancy

    Time frame: After 12 weeks of gestation

    Ongoing pregnancy is defined as the presence of a gestational sac and fetal heartbeat after 12 weeks of gestation.

  4. Miscarriage

    Time frame: before 20 weeks of gestation.

    Miscarriage is defined as spontaneous loss of an intrauterine pregnancy prior to 20 completed weeks of gestational age.

  5. Stillbirth

    Time frame: after 20 weeks of gestation

    Stillbirth is defined as the death of a fetus prior to the complete expulsion or extraction from its mother after 20 completed weeks of gestational age including deaths during labor.

  6. Ectopic pregnancy

    Time frame: After 4 to 6 weeks of embryo transfer

    Ectopic pregnancy is defined as a pregnancy outside the uterine cavity, diagnosed by ultrasound, surgical visualization, or histopathology.

  7. Multiple pregnancy

    Time frame: 7 weeks of gestation

    Multiple pregnancy is defined as a pregnancy with two or more gestational sacs or positive heart beats at 7 weeks of gestation.

  8. Gestational diabetes mellitus

    Time frame: At 28 weeks of pregnancy

    Newly diagnosed diabetes or gestational diabetes at 28 weeks of pregnancy confirmed by 75 g oral glucose tolerance test.

  9. hypertensive disorders of pregnancy

    Time frame: From 20 weeks of gestation up to at birth

  10. preterm birth

    Time frame: At birth

    Delivery of a fetus at less than 37 and more than 28 weeks gestational age

  11. low birth weight

    Time frame: At birth

    Weight of baby born < 2500 g

  12. Very low birth weight

    Time frame: At birth

    Weight of baby born < 1500 g

  13. high birth weight

    Time frame: at birth

    Weight of baby born > 4000 g

  14. large for gestational age

    Time frame: at birth

    large for gestational age is defined as birth weight greater than 90th percentile for gestation, based on standardised ethnicity-based charts

  15. small for gestational age

    Time frame: at birth

    small for gestational age is defined as less than 10th percentile for gestational age at delivery based on standardised ethnicity-based charts.

  16. Early neonatal death

    Time frame: within 7days of birth

    Early neonatal death refers to death of a live born baby within 7days of birth

  17. Congenital anomaly

    Time frame: Birth to first year of life

    Any congenital anomalies detected in baby born

Study contacts

Contact information is provided by the study sponsor or research team.

He Cai

CONTACT

[email protected]

13581613908

Sponsors and collaborators

Lead sponsor

Northwest Women's and Children's Hospital, Xi'an, Shaanxi

Other

Registry information

Official study title

Atosiban in Women With Previous Implantation Failure and Abnormal Uterine Contractions Undergoing Single Blastocyst-Stage Embryo Transfer: A Randomised Triple-Blind, Placebo-Controlled Trial

Important dates

Study start
2025
Primary completion
2027
Study completion
2027
First posted
Sep 22, 2025
Registry last updated
Dec 9, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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