Investigating the effect of estradiol administration duration on pregnancy outcomes of frozen embryo transfer cycles: a double-blind randomized clinical trial

Determining the effectiveness of estradiol treatment duration

219 women who applied for the transfer of gynecological freeze, referring to the infertility treatment center and meeting the conditions for entering the study, will be included; From the second or third day of the menstrual cycle, estradiol is given orally at a dose of 4 to 6 mg; After one week, people will go for the first transvaginal ultrasound to get the thickness of the endometrium. If the thickness of the endometrium is 7 or more and suitable, they will be divided into three groups of 73 people in a double-blind manner. Each person will be placed in one of the groups by one of the randomization methods (combination of random number table and random block method). Selection of blocks will be done using a table of random numbers. Finally, cards will be prepared according to the number of patients, and the type of treatment is specified in these cards. The size of the block and the number of blocks are for the masked therapist and they will not know

This study is carried out in the infertility treatment center of Zainab Hospital in Shiraz. In this study, both patients and doctors will be blind; Patients know the type of intervention, but they do not know the characteristics of the groups.

Patients under 45 years of age with at least two embryos of good quality in the stage of cleavage or blastocyst for transfer and with a healthy uterine cavity that has been confirmed by hysterosalpingograph and hysteroscopy or saline ultrasound

• This study includes 3 groups of 73 people, in the first group, progesterone is started from day 8-11 of receiving estradiol, in the second group, from day 12-14 of receiving estradiol, and in the third group, from day 15-18 of receiving.

Biochemical and clinical pregnancy rates

In this study, firstly, the samples were selected based on the conditions for entering the study and based on the purpose, from among the women referring to the infertility treatment center of Hazrat Zainab (PBUH) who referred to transfer their frozen embryos using the easy sampling method and in available are selected. After that, the researcher obtains the informed consent form by referring to the selected people and introducing himself and briefly stating the type of study and the objectives of the study; Then the women participating in the study are randomly assigned to three short-term, medium-term and long-term intervention groups. All patients are included in the study voluntarily and with the knowledge of random assignment of the intervention. It will be explained to all participants before the start of the study that they will be randomly divided into three intervention groups: short-term (A), medium-term (B) and long-term (C) to randomly divide the samples using the random block allocation method. Bandi is used. In this trial, we will have three groups of 6 blocks (including 2 people participating in drug group A, 2 people participating in drug group B, and 2 people participating in drug group C). The randomization tool is also used from random sequence generation software (random allocation software), which in addition to simple randomization, these random sequence generation software are capable of generating random sequence by block method. The randomization process is done by the study methodology consultant and the clinical researchers are not aware of the randomization process. For concealment, we use Concealment Allocation, which refers to the method used to perform a random sequence on the participants in the study, in such a way that the allocated group is not known before the allocation of the individual. By using sealed opaque letter envelopes with a random sequence (Sequentially numbered, seale, opaque envelopes (, in this method, each of the random sequences created is recorded on a card and the cards are placed inside the letter envelopes in order. In order to maintain a random sequence, the outer surface of the envelopes is numbered in the same order. Finally, the lid of the letter envelopes is glued and placed in a box. At least one week after starting estradiol and when the thickness of the endometrium is 7 or higher; Participants, based on the order of entry of eligible participants into the study, one of the envelopes will be opened and the assigned group of that participant will be revealed.

In this study, after selecting the patients, none of the sample will know about the randomization and allocation process to the groups, and the patients will not have contact with each other and will be visited at separate times. Doctors are given envelopes with coded numbers in advance and patients are entered into study groups in the order of the envelope numbers. Therefore, the present study is double-blind. After receiving estradiol from the second or third day of the menstrual cycle for one week, the patients are divided into three groups receiving progesterone: A- from day 8-11 B- from day 12-14 C- from day 15-18. The doctor who performs the embryo transfer on the day of the end of receiving progesterone does not know which group the patients are in, and only the supervisor of this proposal manages the day of the transfer