To compare the effectiveness and safety of Progesterone Primed Ovarian Stimulation protocol (PPOS) using Dydrogestrone vs GnRH Antagonist Protocol in patients with expected high ovarian response undergoing ICSI cycle

Each patient will be subjected to:

Full history taking. Systematic clinical examination to assess the general condition, body mass index (BMI) and local pelvic physical findings and AFC by trans-vaginal ultrasound on D2 to 3 of menstruation.

Routine labs as CBC, liver & kidney functions to exclude general disease as a contraindication for induction or pregnancy.

Blood sample will be obtained for assessment of basal serum levels of FSH, LH, E2 on days 2- 3 of the cycle. PRL, AMH and TSH Ovarian Stimulation The patients will begin injections of recombinant FSH (rFSH, Gonal-F; Merck-Serono, Italy) from day 2-3 of menstruation, with daily dose of 150-300 IU adjusted according to individual conditions on the basis of the antral follicle count (AFC),hormonal profile, age, body mass index (BMI), and previous ovarian response, according to the standard operating procedures of the center. .

For pituitary suppression, the patients will receive either Dydrogestrone (Duphaston30mg/d; Abbott Healthcare, USA) orally starting at day 2-3 or GnRH antagonist Cetrorelix (CETROTIDE 0.25Mg/d, Merck Serono, Germany) 0.25 mg/day subcutaneously from day 6 of induction until trigger day.

number and size of follicles will be monitored every two days, starting from stimulation day 6 until the day of hCG injection. When most of dominant follicles reach diameter of 18-22 mm, the final oocyte maturation will be induced with 0.2 mg of Triptorelin (2 amp of Decapeptyl 0.1 mg, Ferring Pharmaceuticals, the Netherlands) (agonist trigger). Then, oocyte retrieval will be performed 34-36 h later with freezing of all embryos.

Frozen Embryo Transfer A maximum of 2 embryos will be transferred after endometrial preparation using Estradiol valerate(cycloprogenova) 4mg tab Bayer Pharma AG, Germany) frome day 2 of cycle until endometrial thickness of 8 mm or more then adding progesterone 400 mg(Prontogest 400 IBSA pharmaceutical Italy) vaginal supp twice daily for 5 days and frozen embryo transfer will be on day 5 Transfer will be done by an expert using the same type of ET catheter under ultrasound guidance Adding progesterone 100 mg IM injection every other day if serum progesterone after 1st 4 doses of vag. Prog. is less than 9.2 ng/ml

An infant born alive after 22 weeks gestation was classified as a live birth. Clinical pregnancy is defined as the presence of at least 1 gestational sac on ultrasound at 6 weeks. Ongoing pregnancy is the presence of at least 1 fetus with heart pulsation on ultrasound beyond 10 weeks.

Inclusion Criteria:

1. undergoing trial of ICSI.
2. BMI ≤ 30
3. AMH ≥3.5
4. AFC ≥ 20

Exclusion Criteria:

1. Any known contraindications to the approved fertility drugs.
2. Severe endometriosis.
3. Uterine malformations or abnormal uterine cavity.
4. Uncontrolled endocrinopathies:DM,hyperthyroidism, hypothyroidism
5. Severe male factor
6. History of recurrent ICSI failure or recurrent miscarriage