The normal human menstrual cycle is characterized by an early rise in the level of follicle-stimulating hormone (FSH), which acts on a group of responsive ovarian follicles. Without the FSH, these follicles would have failed to grow and mature. Thus, FSH rescues a group of follicles. Although the majority will proceed to atresia, one or more will mature to the preovulatory stage. Estradiol secreted by the preovulatory follicles will, at an appropriate time, induce a surge in luteinizing hormone (LH) secretion, which triggers oocyte maturation and ovulation. Follicular stimulation and induction of ovulation using exogenous gonadotropins is, in effect, an attempt to mimic these events.
For almost 30 years, human menopausal gonadotropin, an admixture of 75 mIU/mL of purified FSH and LH extracted from the urine of postmenopausal women, has been administered during the follicular phase to stimulate folliculogenesis.
See also p 3290.
Follicular development is monitored by ultrasonography and
Alan H. DeCherney, Frederick Naftolin. Recombinant DNA—Derived Human Luteinizing Hormone: Basic Science Rapidly Applied to Clinical Medicine. JAMA. 1988;259(22):3313–3314. doi:10.1001/jama.1988.03720220059029