Urofollitropin, a natural product like the menotropins, is obtained from the urine of
postmenopausal women and then highly purified so as to contain only FSH, reportedly with only
minute amounts of LH. Urofollitropin is used for its ability to stimulate follicle development, such
as in women undergoing drug-induced pituitary suppression (GnRH antagonist or superagonist)
for purposes of IVF (i.e., multiple follicle development or egg donation). When the number and
size of the ovarian follicles are correct, as determined by ultrasound, hCG is administered so as
to effect ovulation, and the oocytes are retrieved for IVF.
This drug also is indicated for women who have infertility caused by polycystic ovary syndrome,
which generally is observed clinically as enlarged, cystic ovaries containing relatively small
follicles. These patients often develop hirsutism, their androgen and LH levels appear elevated
while their FSH levels are low, and the early exposure to these improper hormone levels may be
causing the follicular atresia. The patient's monthly cycle is controlled by previous pituitary
suppression via treatment with a GnRH superagonist or antagonist; urofollitropin, as an
exogenous source of FSH, is administered and stimulates follicle maturation to preovulatory
size, with little or no exposure of the follicles to additional LH. When the follicles have matured
to preovulatory size, ovulation is assisted by the administration of hCG. The couple is then
advised to engage in sexual intercourse daily, beginning on the day before hCG administration
and until ovulation has occurred.
