Ultra-Long GnRH-a Pretreatment for FET Outcomes in Patients With Deep Infiltrating Endometriosis

What Was Tested

The trial (phase 4) is built around Triptorelin for endometriosis.

It had two arms (groups): Ultra-Long GnRH-a Pretreatment Group (experimental) and Routine HRT Group (active comparator).

Participants in this group will receive ultra-long GnRH-a pretreatment before frozen-thawed embryo transfer. Long-acting GnRH-a will be administered on menstrual cycle days 2 to 4, followed by a second injection 28 to 30 days later. Hormone replacement therapy for endometrial preparation will begin 28 to 30 days after the second GnRH-a injection, followed by frozen-thawed embryo transfer according to routine clinical practice.

Participants in this group will undergo routine hormone replacement therapy for endometrial preparation before frozen-thawed embryo transfer without GnRH-a pretreatment.

The registry classes the interventions as drug and other.

More on the Plan

For patients with deep infiltrating endometriosis who require frozen-thawed embryo transfer, the optimal endometrial preparation strategy remains uncertain.

However, current evidence regarding GnRH-a pretreatment before frozen-thawed embryo transfer in patients with endometriosis is inconsistent, and high-quality prospective randomized controlled studies are limited.

This is a prospective, randomized, controlled, single-center clinical study.

A total of 120 eligible participants will be enrolled.

Who Took Part

Enrollment: 120 planned participants were the target.

It was open to women only aged from 18 years up to 39 years.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: Female patients aged 18 to 39 years. Diagnosed with deep infiltrating endometriosis by ultrasound at the study center. Undergoing the first frozen-thawed embryo transfer cycle with hormone replacement therapy for endometrial preparation. Having at least one good-quality frozen embryo. Willing to participate in this randomized controlled study of GnRH-a pretreatment for deep infiltrating endometriosis and able to personally sign the written informed consent form.

The full record lists 5 inclusion and 7 exclusion criteria; among the exclusions: abnormal chromosomal karyotype; recurrent implantation failure; contraindications to hormone replacement therapy or long-acting gnrh-a treatment.

How the Study Was Run

It was run as a randomized, parallel-group and open-label study.

Because people in this Triptorelin study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

The Triptorelin group and the comparison group ran side by side rather than switching.

Being open-label, the Triptorelin study did not mask who received what.

It started in 2025-08-01 with completion listed for 2026-12-31.

It ran at 1 site in China.

Its stated primary purpose is treatment.

What Was Measured

The main thing measured (primary outcome): Clinical Pregnancy Rate (time frame: 30 ± 3 days after embryo transfer).

It also tracked 5 secondary outcomes, for example Implantation Rate, Ectopic Pregnancy Rate, Early Spontaneous Abortion Rate, Ongoing Pregnancy Rate at 12 Weeks of Gestation and Delivery Rate.

What This Means in Plain Language

Put simply, this is a phase 4, randomized trial of Triptorelin in 120 people with endometriosis.

It is still recruiting; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Triptorelin compound page, Endometriosis research.