IRCT201408021760N36 IRCT 2014-09-17 Vice chancellor for research,Babol University of Medical Sciences Comparison of pregnancy rate in artificial and stimulation cycles with natural cycle in women candidate vitrified Comparison of pregnancy rate in artificial and stimulation cycles with natural cycle in women candidate vitrified 2014-06-22 anticipated 150 Complete https://irct.ir/trial/1300 interventional Randomization: Randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Prevention. 3 In vitro fertilization. Intervention 1: Intervention Group 2: In the second intervention experimental group (Artificial), from the third day of the cycle, Estradiol vale-rate tablets 6 mg is given per day. When the endometrial thickness is greater than 8 mm, the shape and thickness of the endometrium is noted. From this special day, 100 mg injection of progesterone along with Estradiol is given daily. Five days after starting progesterone, blastocyst is transferred. If the endometrial thickness doesn't get to more than 8 mm in 15th day, Estradiol dose will be increased to 8 mg. In this method, the progesterone as a support would be continued till clarifying the pregnancy test in consistency with getting positive of pregnancy test until sixth week to eighth one of pregnancy. Intervention 2: Intervention Group 1: In the first intervention experimental group (Stimulation), patients are taken Clomiphene Citrate tablets 100 mg daily from the fifth day to the ninth day of the cycle. While follicles reach to 18-20 mm, shape and thickness of the endometrium are noted. After 36-38 hours, ovulation is confirmed by vaginal ultrasound, and blastocyst is transferred in 4 days. Intervention 3: Control Group: No drug is given for the control group (natural). While follicles reach to 18-20 mm, shape and thickness of the endometrium are noted. After 36-38 hours, ovulation is confirmed by vaginal ultrasound and in 4 days blastocyst is transferred.