GnRH is a hormone from the hypothalamus (in the brain) which acts on the pituitary gland to secrete (or release) the gonadotropins FSH and LH. These hormones can go on to produce estrogen and progesterone needed during the menstrual cycle.
During IVF, GnRH is blocked so the doctor can control the levels of FSH/LH during ovarian stimulation. Blocking GnRH prevents premature ovulation and allows the doctor to trigger ovulation when the follicles are ready. Blocking GnRH is done using GnRH agonists (ex. lupron) or GnRH antagonists (ex. ganirelix, centrotide).
Synonyms:
GnRH