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IVFNCT05483270

Immediate Versus Postponed Freeze-all Embryo Transfer in Hyperresponders

A study testing the timing of embryo transfer in freeze-all cycles in people with IVF, run by Peking University Third Hospital at 1 site in China.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

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. Read more about this study

Who is it for?
Ages 20 to 42 years, women onlyHealthy volunteers can take part
Conditions the study is for
IVF
What is being tested?
the timing of embryo transfer in freeze-all cycles
Could I receive a placebo?
No, everyone receives an active treatment
How many people
845 participants
Where
1 siteChina
Study dates
30 Aug 2022to 24 Nov 2024
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 20 to 42 years
  • Women only
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • 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.

Who cannot join

  • 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.

Trial locations and contacts

1 site in 1 country.

China1 site

  • Peking university third hospital

    Beijing, 100191

Other trials in China

About this study

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

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.

Read the detailed description

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.

Conditions
IVF
Being tested
the timing of embryo transfer in freeze-all cycles

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • the timing of embryo transfer in freeze-all cyclesBiological

    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.

Study groups in NCT05483270
Study groupRoleWhat they receive
Immediate FET groupActive comparatorFreeze-all embryo transfer will be carried out in the menstrual cycle immediately following oocyte retrieval.
Receives: Biological: the timing of embryo transfer in freeze-all cycles
Postponed FET groupExperimentalFreeze-all embryo transfer will be carried out during the second menstrual cycle to 6 months after oocyte retrieval.
Receives: Biological: the timing of embryo transfer in freeze-all cycles

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Live birth after the first embryo transfer

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

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

Secondary outcomes (16)

  1. Clinical pregnancy

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

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

  2. Ongoing pregnancy

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

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

  3. Biochemical pregnancy

    defined as a positive pregnancy test

    Measured: about 12 days after embryo transfer

  4. Ectopic pregnancy

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

    Measured: about 6 weeks after embryo transfer

  5. Miscarriage

    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.

    Measured: 6-22 weeks of gestation

  6. Cumulative live birth

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

    Measured: 6 month after the first embryo transfer

  7. Pre-eclampsia

    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

    Measured: after 20 weeks of gestation

  8. Gestational hypertension

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

    Measured: after 20 weeks of gestation

  9. Gestational diabetes mellitus

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

    Measured: after 24 weeks of gestation

  10. Premature rupture of membrane (PROM) rate

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

    Measured: the day of delivery

  11. Preterm delivery

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

    Measured: less than 37 and more than 21 weeks' gestational age

  12. Placenta previa

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

    Measured: the day of delivery

  13. Postpartum hemorrhage

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

    Measured: the day of delivery

  14. Birth weight

    Birth weight

    Measured: the day of delivery

  15. Stillbirth

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

    Measured: the day of delivery

  16. Mode of delivery

    Vaginal birth or Caesarean Section

    Measured: the day of delivery

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted2 Aug 2022
  2. Study start30 Aug 2022
  3. Primary completion8 Oct 2024
  4. Study completion24 Nov 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
845 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05483270
Sponsor's protocol ID
Delay-ET-RCT
Status last verified
May 2023
First submitted
20 Jul 2022
Last updated
27 Nov 2024
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Results of the study will be submitted to scientific conferences in reproductive medicine and a peer-reviewed journal.

Questions about this trial

What is this clinical trial studying?

A study testing the timing of embryo transfer in freeze-all cycles in people with IVF, run by Peking University Third Hospital at 1 site in China.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 27 Nov 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Live birth after the first embryo transfer (time frame: At least 22 months gestation after the first embryo transfer cycle). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05483270.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Nov 2024; AzTrials last refreshed its copy on 6 Nov 2026.

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