The use of Clomiphene (Clomid, Serophene) for ovarian stimulation is effective for chronic anovulation, polycystic ovarian syndrome, and unexplained infertility. The term controlled ovarian hyperstimulation (COH) is reserved for the use of injectable fertility medication (Pergonal, Metrodin, Fertinex, Follistim, Humegon, etc.) which requires monitoring by ultrasound and blood work (estradiol assay). The ovaries are stimulated by the injections to produce more than one mature follicle with a mature egg (hyperstimulation). At the same time, the circumstances are carefully orchestrated (controlled) so that intense overstimulation does not occur. Variations in protocol for COH are used in intrauterine insemination, GIFT, and IVF treatment.