The objective of our study is to compare in vitro fertilization (IVF) outcomes between fresh embryo transfer (ET) and frozen-thawed ET in women with polycystic ovary syndrome (PCOS).

Eligible women will be randomized to two groups in a ratio of 1:1 . Both the patients and the clinicians will be aware of the allocated arm. The patients (110) will be equally randomized into two groups:

Group A will undergo a day 3 fresh embryo transfer after ovarian stimulation, luteal phase support will be started just after follicular aspiration. Group B will have all of their embryo cryopreserved after ovarian stimulation with no luteal phase support after the aspiration and then undergo a frozen-thawed day 3 embryo transfer.

Controlled ovarian stimulation will be done using the gonadotropin releasing hormone (GnRH) antagonist protocol then human chorionic gonadotropin( HCG) 5000 IU trigger for final oocyte maturation.

Inclusion Criteria:

• Women diagnosed with PCOS according to modified Rotterdam criteria which includes menstrual abnormalities combined with either hyperandrogenism (hirsutism diagnosed by modified Ferriman-Gallwey score or elevated total testosterone level) or polycystic ovaries.
• Women ages ≥20 and <40years old.
• BMI less than 35.
• Women who have a history of infertility.
• All patients will receive adjuvant drugs for ovulation induction (metformin from preceding cycle, cabergoline 1 tab daily for 8 days and 500 cc colloid solution on day of ovum pick up).

Exclusion Criteria:

• History of unilateral oophorectomy.
• Uterine abnormalities such as a malformed uterus (unicornuate, septate uterus), adenomyosis, submucous myoma or intrauterine adhesion.
• Severe male factor for infertility such as azoospermia.
• History of repeated ICSI trials failure.
• Women who are unable to comply with the study procedures.