IVF Glossary


one of the 2 reproductive cells (sperm or egg) that must unite to form an embryo.

gamete intrafallopian transfer (GIFT)

the direct transfer of sperm and eggs into the fallopian tube for fertilization in the body.

GnRH agonists

a GnRH analogue that triggers the pituitary gland to release LH and FSH. When started at the beginning of an IVF cycle, GnRH agonists also prevent premature ovulation and stimulate follicle growth.

GnRH antagonists

a GnRH analogue that is used to prevent premature ovulation in an IVF cycle. GnRH antagonists have an immediate suppressive effect on the pituitary gland, which prevents the release of LH and FSH.

gonadotropin-releasing hormone (GnRH)

a hormone secreted by the hypothalamus, a control center in the brain, which prompts the pituitary gland to release FSH and LH into the bloodstream.

Adapted from Assisted Reproductive Technology: A Guide for Patients. American Society for Reproductive Medicine, 2011.