RecruitingPhase 3NCT06644794

Progesterone-modified Natural Cycle for FET

Comparison of Progesterone-modified Natural Cycle and Hormone Replacement Therapy Cycle for Endometrial Preparation in Single Frozen Blastocyst Transfer

Sponsor

Shandong University of Traditional Chinese Medicine

Enrollment

336 participants

Start Date

Mar 5, 2025

Study Type

INTERVENTIONAL

Conditions

Infertility, Female

Summary

Hormone replacement therapy (HRT) cycles, despite the ease of synchronizing embryo thawing and embryo transfer timing, increase the risk of pregnancies and obstetric complications compared to natural cycles (NC). By ensuring the presence of the corpus luteum while reducing the number of monitoring sessions, the progesterone modified natural cycle (P4mNC) offers more convenience for the patient than the normal NC. This study is designed to compare the effects of P4mNC and HRT cycles on FET outcomes.

Eligibility

Sex: FEMALEMin Age: 21 YearsMax Age: 44 Years

Inclusion Criteria3

Patients aged 21 to 44 years undergoing FBT
Body mass index (BMI) 18-35 kg/m2
Having regular ovulatory cycles

Exclusion Criteria4

Untreated uterine adhesions
Medical contraindications to estrogen and progesterone therapy
Illnesses contraindicating assisted reproductive technology or pregnancy
History of recurrent implantation failures (> 2 embryo transfer failures)

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Interventions

DRUGProgesterone-modified natural cycle preparation for frozen embryo transfer

A novel endometrial preparation protocol that optimizes the natural cycle, whereby as long as the thickness of the endometrium is suitable for embryo transfer, vaginal progesterone can be used to transform the endometrium before ovulation and subsequently FET.

DRUGHormone replacement therapy cycle preparation for frozen embryo transfer

A traditional endometrial preparation protocol is used for FET, which involves using fixed or flexible exogenous estradiol for artificial cycles. This protocol typically involves starting exogenous estradiol on day 3 or 4 of the cycle, continuing for 7-10 days, and then discontinuing. Upon determining that the endometrial thickness meets the standard, progesterone conversion of the endometrium can be performed.