Glossary of Terms

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The female egg and the male sperm.


A GnRH Antagonist (see definition below) used in IVF cycles to prevent ovulation prior to egg retrieval. 

Gestational Carrier

A woman who accepts to bear (or be pregnant with) the child of another woman who is incapable of becoming pregnant using her own uterus. Women who need surrogates (an older term for what we now refer to as a "gestational carrier") include those who do not have a uterus, have an abnormal uterine cavity, have had several recurrent miscarriages or have had recurrent failed IVF cycles. Women that may have medical problems that would make a pregnancy risky for the mother or baby would also be a candidate to work with a gestational carrier.

Gestational Surrogacy

Also see Surrogate & Classic Surrogacy. In gestational surrogacy, the gestational carrier does not contribute any genetic materials since the egg and the sperm come from prospective parents or a separate donor. 


Gonadotropin releasing hormone is the single most important hormone controlling ovarian function. It is secreted by the hypothalamus and controls LH and FSH secretion by the pituitary gland, which in turn directly controls ovarian function. Absent or abnormal secretion of GnRH results in irregular cycles and lack of ovulation. GnRH is secreted in an episodic manner by the hypothalamus to be able to carry out its functions.

GnRH Antagonist

A synthetic hormone similar to GnRH agonists but without any initial “flare” effect on the pituitary as seen with GnRH agonists. Antagonists (Ganirelix or Cetrotide) are usually administered in IVF cycles during the last 3-4 days of stimulation to prevent an LH surge from occurring, thereby preventing the release of the eggs from the ovaries prior to egg retrieval. 


A synthetic hormone similar to GnRH that is administered in a continuous fashion by daily subcutaneous injections (Lupron) or nasal spray (Synarel). This hormone will actually suppress pituitary and ovarian function. Given this fact, we are able to use the medication to suppress the hypothalamic-pituitary-ovarian axis in many women undergoing ovulation induction for IVF. The benefit of this suppression is that it allows us to control the ovaries ourselves without interference from the hypothalamus or the pituitary.


Follicle Stimulating Hormone (FSH) and Lutenizing Hormone (LH) are pituitary hormones that stimulate egg production, ovulation, and estrogen and progesterone production. The gonadatropin FSH is the hormone that is the main ingredient in Gonal-f, Follistim, Pergonal, Repronex and Humegon. Injections of gonadatropin medications will cause the ovaries to make multiple eggs.


This fertility medication is a gonadatropin hormone containing very pure human FSH. It is produced by cells that have been genetically engineered through recombinant DNA technology to produce large quantities of human FSH. It is self-administered by subcutaneous injection.


A sexually transmitted disease that can cause tubal disease and infertility. If caught early, it is completely curable and will not negatively influence your fertility potential. Common symptoms include pelvic pain, vaginal discharge and fever.