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).
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.