Biology of colorectal cancer in ulcerative colitis

Within the last decade, induction of ovulation with gonadotrophins, specially for patients with polycystic ovary syndrome, has been extensively revisited. On the basis of physiological concepts as the FSH threshold, the FSH window and the hypersensitivity to FSH of selected dominant follicle, news protocols have been described: step-up protocol, step-down, sequential protocol. In this article, their efficacy and safety are discussed. It is presumed that these new protocols would open a new way in the management of ovulation induction.