Comparison of Pregnancy Rates in Modified Natural Frozen Embryo Transfer (FET) Cycle After Luteal Support with GnRH Agonist Versus Progesterone

• Status: NOT_YET_RECRUITING
• Trial end date: 2027-06-01

Summary

Background:

The capability to transfer frozen embryos reduces embryo loss following in vitro fertilization (IVF) and results in higher pregnancy rates compared to a single IVF cycle.

Endogenous progesterone from the corpus luteum, following frozen embryo transfer in natural or modified natural cycles, is expected to provide sufficient luteal support, as observed in spontaneous pregnancies. Nevertheless, research has demonstrated higher pregnancy success rates with additional luteal support. The current standard for luteal phase support involves vaginal progesterone administration.

Several case reports have indicated that administering a gonadotropin-releasing hormone (GnRH) agonist during the luteal phase does not compromise pregnancy continuation achieved through IVF and may, in fact, enhance implantation success.

Studies have shown that the luteal phase can be maintained with a GnRH agonist alone, without the need for progesterone supplementation.

A recent prospective randomized controlled trial compared standard progesterone support with GnRH agonist support in fresh embryo transfers. The group receiving GnRH agonist support demonstrated a significantly higher pregnancy rate.

Given the studies proving the positive impact of GnRH agonist, there is a need for a prospective randomized controlled trial to evaluate the use of GnRH agonist support in frozen embryo transfers.

Aims and Significance:

This study aims to compare pregnancy rates between women receiving GnRH agonist treatment and those receiving standard progesterone-based luteal support during frozen embryo transfers in natural cycles as part of IVF treatments.

Conducting a prospective comparative study will enable us to assess the effectiveness of GnRH agonist treatment relative to standard luteal phase support. Based on the results, the investigators may consider treatment with intranasal GnRH agonist, which improves quality of life and may also enhance pregnancy and live birth rates.

Methods:

The study will be conducted on patients scheduled to undergo modified natural cycles. Participants will be randomly allocated into two groups:

1. Study Group: Luteal phase support will begin on the day of ovulation with Nafarelin nasal spray (200 mcg twice daily) for two weeks, until pregnancy blood test (hCG).

2. Control Group: Luteal phase support will be provided through vaginal progesterone. Endometrin 100 mg twice daily. If the hCG test is positive, the supportive treatment will continue until the 8th week of pregnancy, as per the attending physician's instructions.

Clinical follow-up will include monitoring for clinical pregnancy outcomes, miscarriage rates, and live births.

• Phase: EARLY_PHASE1

Details

• Lead Sponsor: Shaare Zedek Medical Center
• Treatments: Utrogestan