The FET cycle
In the group of TAM, 20 mg per day was giving from day 5 of the menstrual cycle for 5 days. Vaginal ultrasound examinations were performed on day 10 of the cycle to monitor the number and size of developing follicles and endometrial thickness. Ovulation was induced with 10,000 I.U. hCG (human chorionic gonadotropin, Lizhu Pharmaceutical Trading Co.) when the leading follicle reached 18–22 mm and the endometrium thickness reached 7 mm. Day-3 ET was performed four days later while blastocyst transfer was performed six days later. Exogenous progesterone (20 mg/d; Duphaston; Abbott Biologicals B.V.,
Netherlands) was given vaginally starting 2 days after hCG administration.If no dominant follicle developed, a daily dosage of 75 IU hMG (human menopausal gonadotropin, Lizhu Pharmaceutical Trading Co.) was given from day 10 up to hCG injection, with incremental doses of 37.5 IU if needed. If there was no dominant follicle after 15 days of ovarian stimulation or if the follicle reached a diameter of maturity and endometrial thickness did not attain 7 mm, the cycle would be cancelled. If the endometrial thickness did not attain 7 mm when follicle reached a diameter of maturity, the cycle would be cancelled either.
In the group of hormone replacement treatment cycle, oral estradiol val­erate (progynova, Schering, German) was taken 6 mg/d from menstrual cycle day 2-3. An ultrasound assessment was done 12 to 14 days later to assess endometrium thickness. Progesterone 40 mg/d,which would be changed to 60 mg/d 2 days later, was given to transform the endometrium, provided the endometrial thickness exceeded 7 mm. Embryo transfer was performed 3 days after progesterone administration for day-3 embryos or 5 days later for blastocysts. If the endometrium thickness is not adequate, endometrial preparation continued with step-up dose of E2 or adding vaginal estradiol (Femoston, Solvay pharmaceuticals B.V.) 1-2 mg/d till the endometrium thickness reaching 7 mm. Cycles were canceled in patients whose endometrial thickness remained <7 mm after 21 days of continuous estradiol administration.
In both TAM-FET and HRT-FET groups, luteal support was continued to 10 weeks of gestation if a pregnancy achieved.