Immediate Versus Postponed Freeze-all Embryo Transfer in Hyperresponders

Peking University

Status: Completed

Conditions: IVF

Treatments: Biological: the timing of embryo transfer in freeze-all cycles

Study type: Interventional

Funder types: Other

Identifiers

NCT05483270

Delay-ET-RCT

Details and patient eligibility

About

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.

Full 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.

Enrollment: 845 patients

Sex: Female

Ages: 20 to 42 years old

Volunteers: Accepts Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

---

845 participants in 2 patient groups

Immediate FET group

Active Comparator group

Description:

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

Treatment:

Biological: the timing of embryo transfer in freeze-all cycles

Postponed FET group

Experimental group

Description:

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

Treatment:

Biological: the timing of embryo transfer in freeze-all cycles