GnRH Agonist Pretreatment in Persistent Chronic Endometritis Undergoing FET

Association of GnRH Agonist Pretreatment With Pregnancy Outcomes in Women With Persistent Chronic Endometritis Undergoing Frozen Embryo Transfer

Women with PCE represent a treatment-resistant phenotype in whom the endometrial inflammatory and immune status remains abnormal despite antibiotic therapy. GnRH agonist pretreatment may be most beneficial in endometrial phenotypes marked by persistent or residual inflammatory impairment rather than in all frozen embryo transfer populations.We therefore conducted a single-center prospective cohort study to investigate whether GnRH-HRT, compared with non-GnRH-based preparations, improve clinical pregnancy and live birth in women with PCE undergoing FET,

Study Overview

• Status: Not yet recruiting
• Conditions: Chronic Endometritis
• Intervention / Treatment: Drug: GnRH agonist plus estrogen-progesterone for endometrial preparation; Drug: Conventional estrogen-progesterone artificial cycle for endometrial preparation

• Study Type: Observational
• Enrollment (Estimated): 150

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

This prospective cohort study enrolls infertile patients diagnosed with persistent chronic endometritis who receive FET in reproductive center. Subjects are allocated into two groups: down-regulation endometrial preparation group and conventional artificial cycle or natural cycle group. We compare implantation, clinical pregnancy, miscarriage and live birth rates between two regimens.

Description

Inclusion Criteria:

• Aged 20-40 years; confirmed persistent chronic endometritis (PCE) via hysteroscopy plus CD138 immunohistochemistry, defined as positive endometrial pathology after two-course antibiotic treatment for CE.
• Frozen-thawed embryo transfer (FET) with available transferable cleavage-stage or blastocyst embryos from IVF/ICSI cycles.
• No acute pelvic infection at enrollment; ≥1 month elapsed after completion of last antibiotic therapy for endometritis.
• Normal uterine cavity except for inflammatory changes of PCE; no severe uterine malformation or severe intrauterine adhesion requiring surgical intervention.
• Voluntarily sign informed consent and complete full follow-up of pregnancy outcomes

Exclusion Criteria:

• History of pelvic tuberculosis, intrauterine adhesions, submucous uterine myoma or endometrial polyp before FET
• Uncontrolled systemic endocrine disorders, autoimmune diseases (APS, SLE), severe hepatic/renal/cardiopulmonary dysfunction.
• Known allergy to GnRH agonist for down-regulation regimen; prior long-acting GnRH-a intolerance.
• Recent use of immunosuppressant, long-term glucocorticoid or drugs interfering endometrial development within 3 months before enrollment.
• Lost to follow-up or plan to abandon embryo transfer after enrollment.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
GnRH/HRT; PCE patients with GnRH agonist pretreatment combined with hormone replacement therapy (GnRH-HRT) endometrial preparation	Drug: GnRH agonist plus estrogen-progesterone for endometrial preparation; Long-acting GnRH agonist is administered on day 2-3 of menstruation for pituitary down-regulation. After satisfactory hormonal suppression, sequential oral estrogen and progesterone are used to prepare endometrium before frozen embryo transfer in patients with persistent chronic endometritis.
non-GnRH-HRT; PCE patients with non-GnRH-HRT regimens (HRT alone or natural cycle, NC),	Drug: Conventional estrogen-progesterone artificial cycle for endometrial preparation; No GnRH-a down-regulation. Oral estrogen is initiated directly on early menstrual cycle, followed by progesterone transformation to prepare endometrium for FET in patients with persistent chronic endometritis.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical pregnancy rate	Clinical pregnancy was defined as the visualization of at least one gestational sac on transvaginal ultrasonography at 6-7 weeks of gestation	6-7 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
miscarriage rate	Miscarriage rate was defined as the proportion of clinical pregnancies ending in spontaneous pregnancy loss before 24 gestational weeks. Early miscarriage was defined as pregnancy loss occurring before 12 weeks of gestation.	24 weeks
Live birth rate	Live birth was defined as the delivery of at least one live-born infant at ≥24 weeks of gestation.	37 weeks

Collaborators and Investigators

• Sponsor: Guoxia Yang

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): June 1, 2028

Study Registration Dates

• First Submitted: June 4, 2026
• First Submitted That Met QC Criteria: June 10, 2026
• First Posted (Actual): June 11, 2026

Study Record Updates

• Last Update Posted (Actual): June 11, 2026
• Last Update Submitted That Met QC Criteria: June 10, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Pituitary Hormone-Releasing Hormones; Hypothalamic Hormones; Peptide Hormones; Neuropeptides; Peptides; Amino Acids, Peptides, and Proteins; Oligopeptides; Nerve Tissue Proteins; Proteins; Gonadotropin-Releasing Hormone
• Other Study ID Numbers: PCE