Cryopreserved-thawed Embryo Transfer With or Without Gonadotropin Releasing Hormone Agonist

Cryopreserved-thawed Embryo Transfer in Down or Non-down Regulated Hormonally Controlled Cycles: a Prospective, Randomized Study

Traditionally, the use of GnRH-a suppression was considered essential for adequate endometrial hormonal modulation in cryopreserved-thawed embryo transfer cycles. Several studies, however, have questioned its necessity for controlled endometrial preparation. Using a high dose of estradiol from day 1 of the cycle will suppress the gonadotroph, preventing folliculogenesis and excessive secretion of LH, allowing adequate endometrial preparation without GnRH-a.

Inclusion Criteria:

• 20-35 years
• BMI 20-30
• Regular menses.
• No PCOS, no endometriosis
• No uterine anomalies or lesions
• No severe male factor
• All grade 1 cleaved stage embryos

Exclusion Criteria:

• Less than 20 or more than 35 years
• BMI less than 20 or more than 30
• Irregular cycles
• PCOS or endometriosis
• Uterine anomalies or lesions
• Severe male factor
• Poor quality embryos for transfer
• Severe