Ovarian hyperstimulation syndrome (OHSS) is a common complication during controlled ovarian stimulation (COH) in ART.In the other extreme, very poor ovarian response to gonadotropins and subsequent cancellation of IVF cycle are the major stress to the patients and the physicians as well.It therefore will be most helpful to identify efficient strategies or parameters to individualize the gonadotropin doses in COH in order that the clinical risks can he minimized along with the optimized treatment burden.Some reproductive hormones (basal FSH, estradiol, AMH, inhibin B levels), age of the female partner, and ultrasound examination (antral follicle count; AFC) have been used to predict the ovarian responses and the retrievable numbers of eggs during COH.