الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Our study was a prospective study on 40 infertile patients who had undergone ICSI, their ages ranged from 20 to 38 years old and their E2 ≥ 2000 pg/ml.
We started induction of ovulation with long agonist protocol; the number of oocytes retrieved was ≥ 20 oocytes. ICSI and embryo freezing were done, and then GnRH antagonist (Cetrotide 0.25 mg/day) was started simultaneously with aromatase inhibitor (Letrozole 2.5 mg/twice daily) in the same day of oocyte retrieval for five consecutive days.
The aim of our study was to determine the effect of GnRH antagonist and aromatase inhibitor on luteal phase hormonal profile in freeze all cycles to prevent OHSS.
GnRH is considered the key regulator of reproductive function in the hypothalamus. It is the final output from the hypothalamic neuronal network that feeds down to regulate reproductive function.
Gonadotropin-releasing hormone (GnRH) analogues are widely used in assisted reproduction to suppress the surge of the endogenous luteinizing hormone (LH).
Ovarian hyperstimulation syndrome is a potentially life-threatening, but preventable iatrogenic complication of IVF treatment. In recent years, new strategies have been developed to minimise the risk of ovarian hyperstimulation syndrome after in vitro fertilization. The biggest cause of OHSS is the presence of hCG. In early OHSS, the cause is exogenous hCG while in delayed OHSS the cause is often due to production of endogenous hCG following the pregnancy.
OHSS results in ovarian enlargement and a shift of protein-rich fluid from the vascular compartment into the third space compartments (particularly the peritoneal and pleural cavities), leading to the potentially fatal complications of renal failure through hypoperfusion, and thromboembolism by haemoconcentration and increased viscosity.
The results of our study showed that the administration of GnRH antagonist (Cetrotide 0.25 mg/day) simultaneously with aromatase inhibitor (Letrozole 2.5 mg/twice daily) on the same day of oocyte retrieval for five consecutive days decreased the level of E2 and prevented OHSS in the patients with no changes in the hematological parameters.
Patient’s E2 decreased to 30% of its initial value after treatment. Also there was no hemoconcentration as the levels of creatinine, WBC and hematocrit didn’t change significantly. There were no signs of OHSS as ovarian size and abdominal circumference didn’t change significantly.
The technique of freezing all and shutting down the cycle by GnRH antagonists (Cetrotide) with Aromatase inhibitors (Letrozole) was associated with 51.2 % pregnancy rate in the frozen embryo transfer (FET) cycle.
Luteal phase GnRH antagonist administration has also been proposed for a different purpose that of managing established severe early ovarian hyperstimulation syndrome (OHSS).
It has been reported that luteal GnRH antagonist administration in patients with established severe early OHSS appears to prevent patient hospitalization and results in quick regression of the syndrome on an outpatient basis.
Aromatase is a cytochrome P450 hemoprotein-containing enzyme complex that catalyzes the rate-limiting step in the conversion of androstenedione and testosterone to Estrone and Estradiol (E2).
Letrozole (Femara) is the most commonly used aromatase inhibitor. The administration of 2.5 mgs of Letrozole during the luteal phase has an impact on corpus luteum function.it reduces serum E2 levels which allow a faster recovery of LH concentration. This may be of interest not only for egg donors but also in patients at high risk of OHSS who freeze all their embryos or who cancel hCG administration to reduce potential risk that high E2 levels pose.
Freezing all oocytes or embryos and transferring in the next cycle has recently been proposed that is called segmentation of IVF cycle.
This procedure has been used with very good results in women who were exposed to risk of OHSS and in women who needed fertility preservation.