The first In-Vitro Fertilization cycles were performed in natural unstimulated cycles. Today gonadotrophins are administered to induce multiple follicular development and controlled ovarian hyperstimulation. During ovarian stimulation gonadotrophin-releasing hormone analogues are co-administered in order to prevent premature luteinizing hormone surges. Premature luteinizing hormone surges are observed in about 20% of stimulated cycles without using gonadotrophin-releasing hormone analogues .

Avoiding the adverse effects of elevated luteinizing hormone levels, first gonadotrophin-releasing hormone agonist analogues were used to supplement the gonadotrophin stimulation. The continuous administration of gonadotrophin-releasing hormone agonists causes gonadotrophin suppression through down-regulation and desensitization of the gonadotrophin-releasing hormone receptors in the pituitary gland after an initial short period of gonadotrophin hypersecretion .

Gonadotrophin-releasing hormone antagonists (cetrorelix and ganirelix) cause immediate and rapid gonadotrophin suppression by competitive antagonism of the gonadotrophin-releasing hormone receptor in the pituitary without an initial period of gonadotrophin hypersecretion. Several advantageous effects of cetrorelix were established , and these effects seemed to be independent from the type of antagonist used for luteinizing hormone-suppression.The quality of oocytes and developing preembryos is one of the most relevant factors determining the success of an In-Vitro Fertilization treatment. As ovarian stimulation protocol is one of the eligible factors during an In-Vitro Fertilization treatment, its embryo quality influencing effects are necessary to know.

Inclusion Criteria:

1. Unexplained infertility.
2. Tubal factor. Included treated hydrosalpinx and pyosalpinx
3. first cycle .
4. Body mass index: 18-29.
5. Follicle stimulating hormone not more than 14 , E2 not more than 80 and Antimullerian hormone >1.
6. Antral follicular count: more than 5 follicles in one ovary.
7. combined factors .
8. Normal male semen analysis: Mild male factor: concentrations 10 million - 20 million sperm/ml. Moderate male factor : concentrations 5 million - 10 million sperm/ml.

Exclusion Criteria:

1. Patients with Endometriosis.
2. Azoospermic male.
3. Body mass index more than 29.