降调节与卵巢反应性

Down regulation and ovarian response

Since COS in IVF creates the multiple follicle development which result in the rapid increase of E2 level and sensitivity to pituitary,reduce the bioactivity of GnSAF,bring about the premature LH surge occurren.It would harm the oocyte quality,which can be prevented by administration of GnRH-a.GnRH-a competes to occupy the receptor on pituitary.Thus,pituitary became desensitization clinically called as pituitary down regulation.It has been routinely used in COS for more than twenty years.However,the high dose of GnRH-a strongly inhibits the pituitary ovary axe,and led to the super suppress of ovarian response.The low dose of the GnRH-a or GnRHant has been recommended nowadays.Ovarian response is important for ART,so many indexes to evaluate the ovarian reserve.Some of them are available,such as age,FSH and AFC.For poor responder,the first experience of COS is the best evidence.Asymmetry follicle development and poor ovarian reserve are the most common in poor responder.The former can be adjusted by down regulation protocol and Gn dose administration,the later may take the oocyte donation into consideration.