A GnRH-analog that briefly stimulates the pituitary gland to release follicle stimulating hormone (FSH) and luteinising hormone (LH), but then within a few days reduces these hormones to low levels (you could say that the pituitary has had a clamp put on it), stopping these hormones from competing with administered hormones -- and, particularly in women, suppressing the LH surge that otherwise can spoil the timing of egg retrieval in an assisted conception program such as IVF or GIFT. Examples include: leuprorelin(Lucrin, made by Abbott, used in Australia and Europe) or leuprolide (Lupron, made by Abbott in the US); nafarelin (Synarel, by Syntex); goserelin (Zoladex, by ICI); triptorelin (Decapeptyl, by Ipsen Biotech and used in Europe) and buserelin (Suprefact, by Hoechst, used in Europe).

An abnormal condition of the uterus in which glands from the endometrium grow into the muscle of the wall of the uterus (the myometrium), causing local or general enlargement of the uterus, pain with periods, and perhaps heavier periods. A localised area of adenomyosis is called an adenomyoma and can be hard to distinguish from a fibroid on transvaginal ultrasound, although an increase in the serum CA 125 antigen level can point to the correct diagnosis. Unlike a fibroid it is not easily removed at surgery, because it's not clearly separable from surrounding tissue. There's no satisfactory long term treatment for adenomyosis: hysterectomy may be chosen if symptoms are bad enough. GnRH-agonists give just temporary relief.

A GnRH-agonist, made by Hoechst as Suprefact. Administered as a nasal spray.

A GnRH-agonist, made by Ipsen Biotech as Triptorelin. Administered by a monthly injection.

A GnRH-analog that (unlike GnRH-agonists) immediately stops the pituitary gland from releasing the gonadotropins follicle stimulating hormone (FSH) and luteinising hormone (LH). Can substitute for GnRH-agonists for many gynecological purposes (particularly to suppress the LH-surge in assisted conception), although its use with pure FSH preparations (such as Fertinex, Gonal-F, Metrodin HP or Puregon) can lead to poor egg quality unless the dosage is carefully controlled or some luteinising hormone is added to the stimulation regimen.

A GnRH-agonist, made by ICI as Zoladex. Administered by monthly injection.

A sudden and huge increase in production of luteinising hormone by the pituitary gland in response to sustained and substantial levels of estradiol in the blood in women, midway through the ovarian cycle. Causes ovulation about 36 hours after it starts (about 20 hours after its peak). If not suppressed during assisted conception (see GnRH-agonists and GnRH-antagonists) it can start before human chorionic gonadotropin has been given, so spoiling the timing of egg retrieval. Timely production of the LH surge in adult women depends on female conditioning of the hypothalamus and/or the pituitary gland before birth. Detectable by testing the urine with a special kit.

A treatment protocol for using GnRH-agonists that involves their use for more than a week before injections of follicle stimulating hormone (FSH) start for induction of superovulation in assisted conception programs. The advantage is that any temporary rise in luteinising hormone levels and progesterone levels has dissipated before the development is under way of those ovarian follicles from which eggs will be obtained at egg retrieval. The disadvantage, compared with the short protocol, is that higher (hence more expensive) doses of GnRH-agonist and FSH are needed. The GnRH can be started with menstruation or during the luteal phase of the previous cycle.

Early experience with superovulation for in vitro fertilisation, particularly at the original US program in Norfolk VA, saw women patients classified into three classes of responders, depending on how many eggs were obtained at egg retrieval. Poorer than usual outcomes could occur with either a low response or a high response (the high responders generally have polycystic ovaries, with a risk of ovarian hyperstimulation syndrome (OHSS). Many maneuvers have been used to try and retrieve more eggs among low responders, such as starting high dose FSH on day 1, the adding of growth hormone, the avoidance of GnRH-agonists etc., all generally without improving the results. Day 3 serum FSH levels can be high in low responders, indicating a depletion of eggs in the ovaries.

(LH) The hormone, or gonadotropin, produced by the pituitary gland to cause, in women, ovulation of a mature follicle in the ovary, resulting in formation of the corpus luteum; in men, stimulates the production of testosterone by the Leydig cells of the testis. Suppressed by GnRH-agonists and GnRH-antagonists, so that (for ovulation induction) an injection of human chorionic gonadotropin (hCG), which acts the same way, has a predictable time course of action. A small amount of LH is essential for normal function of the tertiary follicle and the corpus luteum. Recombinant LH is under development by Serono as Luveris, but its clinical role in place of hCG is not yet established.

A GnRH-agonist, made by Syntex as Synarel and used as a nasal spray.

A treatment protocol for controlled stimulation of the ovaries using GnRH-agonists with injections of follicle stimulating hormone (FSH) for induction of superovulation in assisted conception programs involves starting the GnRH-agonist a day or two before the injections of FSH start. The advantage is one of cost: less FSH (and less GnRH-agonist) are used compared with the long protocol. The disadvantage is that luteinising hormone levels and progesterone levels can rise, possibly (in some cycles of treatment) spoiling optimal development of ovarian follicles. The GnRH-agonist is continued (in contrast to the ultrashort protocol) until follicles are mature and human chorionic gonadotropin is given to start the process of ovulation.

A GnRH-agonist, made by Syntex. Administered as a nasal spray.

A GnRH-agonist marketed by Ipsen Biotech as Decapeptyl.

A variation of the short protocol for using GnRH-agonists with injections of follicle stimulating hormone (FSH) for controlled induction of superovulation in assisted conception programs. The GnRH-agonist is started with menstruation, a day or two before the injections of FSH start, and is discontinued after about 5 days from starting it (i.e. often a week or more before ovulation). There are no special advantages, whereas there's a potential disadvantage: a much more thorough suppression of the woman's own luteinising hormone (and maybe FSH) than if the GnRH-agonist is continued -- potentially causing stimulated follicles to 'run out of puff' before they are fully mature. The ultrashort protocol should not be used with pure forms of FSH, such as Fertinex, Gonal-F, Metrodin HP or Puregon, or poor egg quality will result if some luteinising hormone is not administered.