Several preparation methods have been proposed for FET in artificial cycles. Exogenous estrogen is administered early in the follicular phase in order to induce endometrial proliferation and inhibit spontaneous ovulation, with progesterone added days before the embryo transfer.. Estrogen can be given as an oral or a vaginal tablet, a transdermal patch, and a subcutaneous or intramuscular injection, with no significant differences in outcomes.
On our study we aimed to compare between two protocols of estrogen administration either ascending dose or fixed constant dose starting from day two of cycle.
This study was designed as a prospective clinical trial. It was conducted in 84 patients were divided into two treatment groups .the first group underwent endometrial preparation bya constant dose of (Estradiol valerate) in a form of Progynova® 6 mg/day orally each day form second day of menstrual period of a spontaneous or induced cycle until endometrial thickness (> 9 mm, < 14 mm) ,on the other hand the second group underwent endometrial preparation an ascending (Estradiol valerate) in a form of Progynova® orally 2 mg/day from day (1: 5), 4 mg/ day from day (6:10), 6 mg from day 10 until endometrial thickness (> 9 mm, < 14 mm).