As the negative feedback of estrogen is inhibited, the hypothalamus secretes GnRh which in turn stimulates the anterior pituitary to secrete LH and FSH which help in ovulation. Between 60 and 85% of women, mostly with polycystic ovary syndrome (PCOS), ovulate successfully in response to clomiphene with a cumulative pregnancy rate of 30 to 40%.[8][9][10]