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Completed

NCT Number: NCT05483270

Immediate Versus Postponed Freeze-all Embryo Transfer in Hyperresponders

This is a multicenter, randomised controlled trial. The investigators plan to randomise 836 participants to the immediate FET or the postponed FET from the day of oocyte retrieval to the last day of that menstrual cycle in a 1:1 rate. Primary outcome will be the live birth rate after the embryo transfer.

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Key information

Conditions

IVF

Age range

20 year–42 year

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Primary location

Peking university third hospital

Beijing, 100191, China

About this study

It is postulated that postponing embryo transfer for at least one menstrual cycle after a freeze-all cycle can minimise the possible residual negative effect caused by ovarian stimulation and can promote the resumption of a normal ovulatory cycle and the receptivity of endometrium. Nevertheless, emerging evidence suggests a higher live birth rate in the immediate freeze-all embryo transfer (FET) cycles compared to that in the delayed group. It is unclear the whether postponed FET is superior in hyperresponders. The investigators hypothesize the success rate in the postponed FET for at least one menstrual cycle after oocyte retrieval is higher than in the immediate FET in hyperresponders.

Objective: To evaluate whether the postponed FET for at least one menstrual cycle after oocyte retrieval is superior to the immediate FET in the first menstrual cycle after oocyte retrieval in hyperresponders in terms of live birth rates.

Design: a multicenter, randomised controlled trial Patients: The investigators plan to randomise participants to the immediate FET and the postponed FET from the day of oocyte retrieval to the last day of that menstrual cycle.

Primary outcome: live birth rate after the embryo transfer. Patients who get pregnant will be followed up until 6 weeks after delivery.

Sample size: The investigators plan to enroll 836 participants in a 1:1 rate.

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • Women aged 20 to 42 years old;
  • Written informed consent;
  • Women scheduled for freeze-all embryo transfer;
  • Women with the number of oocyte collected higher than 15.

Exclusion criteria

  • Women with a history of at lease three failed transfer cycles;
  • Women with an endometrial thickness less than 7 mm on the triggering day;
  • Severe uterine malformations.

Treatment and study plan

the timing of embryo transfer in freeze-all cycles

Biological

Immediate FET group Freeze-all embryo transfer will be carried out in the menstrual cycle immediately following oocyte retrieval.

Postponed FET group Freeze-all embryo transfer will be carried out during the second menstrual cycle to 6 months after oocyte retrieval.

Primary outcomes

  1. Live birth after the first embryo transfer

    Time frame: At least 22 months gestation after the first embryo transfer cycle

    Live birth is defined as the delivery of at least one baby after 22 weeks of gestation that exhibits any sign of life.

Secondary outcomes

  1. Clinical pregnancy

    Time frame: around 7 weeks' gestation after the first embryo transfer cycle

    defined as at least one gestational sac on ultrasound at around 7 weeks' gestation with the detection of heart-beat activity

  2. Ongoing pregnancy

    Time frame: 12 weeks' gestation or beyond after the first embryo transfer cycle

    defined as pregnancy with detectable heart rate at 12 weeks' gestation or beyond

  3. Biochemical pregnancy

    Time frame: about 12 days after embryo transfer

    defined as a positive pregnancy test

  4. Ectopic pregnancy

    Time frame: about 6 weeks after embryo transfer

    defined as embryo implanted at any site other than the endometrial lining of the uterus cavity

  5. Miscarriage

    Time frame: 6-22 weeks of gestation

    defined as spontaneous loss of a clinical pregnancy before 22 completed weeks of gestational age, in which the embryo(s) or fetus(es) is/are nonviable or is/are absorbed or expelled from the uterus.

  6. Cumulative live birth

    Time frame: 6 month after the first embryo transfer

    the cumulative rate of live born children conceived within six months of the first FET cycle.

  7. Pre-eclampsia

    Time frame: after 20 weeks of gestation

    defined as the development of gestational hypertension with proteinuria (≥300 mg/24-hour urine collection or 30 mg/dL in single urine sample) of new onset after 20 weeks of gestation

  8. Gestational hypertension

    Time frame: after 20 weeks of gestation

    defined as the development of blood pressure greater than 140/90 mmHg after pregnancy without proteinuria or other signs of preeclampsia

  9. Gestational diabetes mellitus

    Time frame: after 24 weeks of gestation

    defined as carbohydrate intolerance of variable severity with onset or first recognition during pregnancy as determined from the diagnosis in the obstetrical medical record

  10. Premature rupture of membrane (PROM) rate

    Time frame: the day of delivery

    defined as rupture of the amniotic membranes before the onset of labor including PROM at term and preterm PROM

  11. Preterm delivery

    Time frame: less than 37 and more than 21 weeks' gestational age

    defined as delivery of a fetus at less than 37 weeks' gestational age

  12. Placenta previa

    Time frame: the day of delivery

    defined as a placenta that is implanted over or very close to the internal cervical orifice

  13. Postpartum hemorrhage

    Time frame: the day of delivery

    defined as the loss of 500 ml of blood or more after completion of the third stage of labor

  14. Birth weight

    Time frame: the day of delivery

    Birth weight

  15. Stillbirth

    Time frame: the day of delivery

    defined as the absence of signs of life at or after birth

  16. Mode of delivery

    Time frame: the day of delivery

    Vaginal birth or Caesarean Section

Sponsors and collaborators

Lead sponsor

Peking University Third Hospital

Other

Collaborators

  • Shengjing Hospital
  • The Affiliated Hospital Of Guizhou Medical University
  • Women's Hospital School Of Medicine Zhejiang University

Registry information

Official study title

Immediate Versus Postponed Freeze-all Embryo Transfer in Hyperresponders, a Multicenter Randomised Controlled Trial

Important dates

Study start
2022
Primary completion
2024
Study completion
2024
First posted
Aug 2, 2022
Registry last updated
Nov 27, 2024

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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