The aim of this study is to investigate the role of GDF-8 in regulating progesterone levels during controlled ovarian stimulation in patients undergoing ICSI-ET and to evaluate its effects on pregnancy rates.

The main questions are

• Does serum GDF-8 correlate with serum Progesterone levels during ovarian stimulation?
• Does serum GDF-8 serum level at different time-points during ovarian stimulation correlate with pregnancy rate?

participants will undergo ICSI-ET cycle using the long GnRH-agonist protocol and serum levels of GDF-8 and progesterone will be measured at three time-points during the trial: on day of hCG trigger administration, on day of oocyte pickup, and 14 days after embryo transfer

Inclusion Criteria:

• The study population included women who underwent their first ICSI-ET cycles due to male and/or tubal factors or unexplained infertility, aged 20-35 years, whose BMI ranged from 19-29.9 kg/m2, with regular menstrual cycles

Exclusion Criteria:

• women with PCOS, couples with azoospermic husbands, women with poor ovarian reserve testing (AMH < 1.2 ng/dl and/or AFC < 5), women diagnosed with endometriosis, and women with medical comorbidities such as thyroid disorders, DM, hyperprolactinemia, etc.