This study is a randomized controlled clinical trial to compare the pregnancy outcomes of infertile women with frozen embryo transfer. The study population in frozen embryo transfer cycles receive three doses of human chorionic gonadotropin (HCG) to recognize the effectiveness of HCG on pregnancy outcomes in Reproductive Biomedicine Research Center, Royan institute, Tehran Iran.

During implantation, the biochemical crosstalk between the endometrium and embryo has a very important role. The endometrium secrets cytokines and growth factors that modulate embryonic differentiation and early development. One of the important molecular messages between the embryo and endometrium is human chorionic gonadotropin (HCG). HCG is expressed by the blastocyst before the implantation, while increasingly produced after implantation by the syncytiotrophoblast. In order to study the direct effect of HCG on the endometrium at implantation, this randomized, controlled clinical trial evaluated whether HCG supplementation would be beneficial for pregnancy outcomes of cryopreserved-thawed embryo transfer with estrogen/ progesterone replacement cycles at Royan Institute.

Block randomization method is designed by epidemiologist using STATA software version 13 and the number of blocks considered is 6. The random allocation list for patients is solely available to the epidemiologist. In order to hide the random allocation process, a total of 200 envelopes are prepared, and only the methodologist has been aware of table of random numbers. When the doctor declared the patient's eligibility, the methodologist provided the doctor with the envelope. The group will be selected and based on the type of group mentioned in the envelope.

Inclusion Criteria:

• Infertile women candidates for frozen embryo transfer
• Age 20-40 years
• Body Mass Index under than 30 Kg/m2
• Having at least three good quality embryos

Exclusion Criteria:

• Women with hematologic and autoimmune disorders
• Couples with chromosomal and genetic abnormalities
• Women with uterine anomalies
• Women with uterine and ovaries surgical history
• Women with endometriosis and adenomyosis
• Women with hydrosalpinx
• Women with uterine fibroids
• Women with history of recurrent abortion or recurrent implantation failure
• Severe male factor infertility (azoospermia)
• Embryo donation cycle
• Endometrial thickness less than 8 millimeter on the day of embryo transfer

After the publication of the article Available to the public. Scientific use by citing the source. Request via e-mail

After the publication of the article

Available to the public. Scientific use by citing the source.