Estrogen (Gel)Transdermal vs Oral Estrogen for Endometrial Preparation

Safety and Efficacy of Transdermal Estrogen (Gel) Versus Oral Estrogen for Endometrial Preparation in Down-regulated Frozen Embryo Transfer (FET) Cycles-An Open-label Multi Centric Randomized Controlled Trial

The goal of this randomized study trial is to comparing transdermal estradiol gel and oral estradiol for endometrial preparation in the Frozen Embryo Transfer Cycle. The main question[s] it aims to answer is: • Can Transdermal estrogen (gel) can be equally efficacious as compared to oral estrogen in hormone replacement FET (HRT- FET) cycles ? The Transdermal gel would have the added benefit of a higher patient comfort with fewer side effects and a better safety profile. Participants planned for Frozen embryo transfer will undergo H-P-O axis suppression on previous cycle D21 of menses with gonadotropin-releasing hormone(GnRH) agonist depot preparation (Inj. Decapeptyl 3.75 mg) IM . The study will compare Transdermal E2 gel with Oral E2 tabs. The patients will be randomized into an oral and gel group, and all patients will participate only once in the study.

Estrogen priming is essential for the induction of progesterone receptors and to build endometrial thickness, both of which play an important role in regulating endometrial receptivity . Different routes of Estrogen administration are oral (tablets), transdermal (patch/gel), and vaginal (tablets).

Inclusion Criteria:

• Infertile patients aged 23-35 years.
• BMI 18.5 to 29.9 kg/m2.
• A normal uterine cavity assessed by 3D ultrasound (USG)/hysteroscopy.
• Patients who underwent IVF/ICSI and who have cryopreserved their embryos.
• Those receiving donor oocytes or donor embryos.
• Patients undergoing hormonal replacement frozen embryo transfer (HRT-FET) cycles with GnRH agonist suppression.
• Embryo Transfers of good quality embryos -2/3/4/5 AA, AB, BA(As per Gardner Grading System).

Exclusion Criteria:

• Preimplantation Genetic Testing for Aneuploidies (PGT-A) cycles.
• Patients who had a FET performed in natural or stimulated cycles.
• Patients who had more than 2 failed transfers due to thin endometrium.
• Patients having uterine anomalies.
• Known cases of adenomyosis and endometriosis.
• Underlying cardiac/renal/hepatic/thromboembolic disorders, h/o anxiety or depression.
• E2 >50 pg./ml, P4 > 1 ng/ml and on D2 of menses.
• On D2 scan presence of a cyst or a dominant follicle.
• Patients with a history of recurrent 1st-trimester abortions.