Purpose of the Study:

To compare the effectiveness of GnRH agonist downregulation alone versus GnRH agonist combined with letrozole in improving pregnancy outcomes in women with adenomyosis undergoing frozen embryo transfer (FET).

Research Question:

Is the combined use of GnRH agonist and letrozole more effective than GnRH agonist downregulation alone in achieving better ongoing pregnancy rates in adenomyosis cases undergoing FET?

Hypothesis:

Null Hypothesis (H₀): The combined use of GnRH agonist and letrozole is not more effective than GnRH agonist downregulation alone in achieving a higher ongoing pregnancy rate in adenomyosis cases undergoing FET.

Study Outcomes:

Primary Outcome: Ongoing pregnancy rate at 12 weeks of gestation.

Inclusion Criteria:

Diagnosis of adenomyosis confirmed via transvaginal ultrasound as per MUSA criteria History of infertility requiring frozen embryo transfer (FET). Availability of at least one good-quality frozen embryo for transfer

Exclusion Criteria:

BMI ≥ 30 kg/m2 Presence of endocrine disorders; (uncontrolled diabetes mellitus, / hyperprolactinemia, thyroid dysfunction, Congenital adrenal hyperplasia, Cushing syndrome, or polycystic ovary syndrome Previous major uterine surgery Gestational carrier Fertility preservation

Women diagnosed with adenomyosis who are undergoing frozen embryo transfer (FET) as part of their fertility treatment.

he Individual Participant Data (IPD) will be shared with authorized researchers upon request. The supporting documents, including the study protocol, SAP, and ICF, will be provided alongside the IPD to ensure comprehensive understanding and proper data interpretation.

When: IPD will be available after the completion of the study and publication of primary results.

How: IPD will be shared through a secure data repository or via encrypted files sent through secure email upon request, following proper data use agreements.

After publication