Amenorrhoea
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225207955
2008-07-12T13:42:25Z
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[[ca:Amenorrea]]
{{DiseaseDisorder infobox |
Name = Amenorrhoea |
ICD10 = {{ICD10|N|91|0|n|80}}-{{ICD10|N|91|2|n|80}} |
ICD9 = {{ICD9|626.0}} |
}}
'''Amenorrhoea''' ([[British English|BE]]), '''amenorrhea''' ([[American English|AmE]]), or '''amenorrhœa''', is the absence of a [[menstrual period]] in a woman of reproductive age. Physiologic states of amenorrhoea are seen during [[pregnancy]] and [[breastfeeding|lactation]] (breastfeeding), the latter also forming the basis of a form of contraception known as the [[lactational amenorrhea method]]. Outside of the reproductive years there is absence of menses during childhood and after [[menopause]].
Amenorrhoea is a symptom with many potential causes. Primary amenorrhoea (menstruation cycles never starting) may be caused by developmental problems such as the congenital absence of the uterus, or failure of the [[ovary]] to receive or maintain [[egg cells]]. Also, delay in pubertal development will lead to primary amenorrhoea. Secondary amenorrhoea (menstruation cycles ceasing) is often caused by hormonal disturbances from the [[hypothalamus]] and the [[pituitary gland]] or from premature [[menopause]], or intrauterine scar formation.
==Etymology and history==
The term is derived from [[Greek language|Greek]]: ''a'' = negative, ''men'' = month, ''rhoia'' = flow. Derived adjectives are '''amenorrhoeal''' and '''amenorrheic'''. The opposite is the normal [[menstrual period]].
==Classification of amenorrhoea==
Types of amenorrhoea is diagnosed based on several factors which include the age of onset, and level of hormonal involvement.
===Age of onset===
There are two types of amenorrhea: primary and secondary amenorrhea. Primary amenorrhoea is the absence of menstruation in a woman by the age of 16. Also, as pubertal changes precede the first period, [[menarche]], women who have no sign of [[thelarche]] or [[pubarche]] and thus are without evidence of initiation of [[puberty]] by the age of 14 have primary amenorrhoea. (Reference: Speroff L et al, Clinical Gynecologic Endocrinology and Infertility, 1999)
Secondary amenorrhoea is where an established menstruation has ceased - for three months in a woman with a history of regular cyclic bleeding, or six months in a woman with a history of irregular periods. This usually happens to woman aged 40-45. Amenorrhoea may cause serious pain in the back near the pelvis and spine. This pain has no cure but can be relieved by doses of progesterone. Progesterone will also help the bleeding or dark colored urine from a woman's vagina.
====Primary amenorrhoea====
# Gonadal dysgenesis, including [[Turner Syndrome]].
# [[Mullerian agenesis]] (Mayer-von-Rokitansky-Küster-Hauser syndrome (MRKH)).
# [[Androgen insensitivity syndrome]].
# Delay in hypothalamic-pituitary maturation.
# Olfacto-genital dysplasia, [[Kallmann syndrome]].
# Vaginal obstruction, [[cryptomenorrhea]], [[imperforate hymen]].
# Receptor abnormalities for FSH, LH.
# Specific forms of [[congenital adrenal hyperplasia]]
# [[Swyer syndrome]]
# [[Galactosemia]]
# [[Aromatase]] deficiency
# [[Prader-Willi syndrome]]
# Male pseudo-[[hermaphroditism]] (about 1 in every 150,000 births)
# Other [[Intersexuality|intersexed]] conditions
====Secondary amenorrhoea====
# [[Pregnancy]]
# [[Anovulation]]
# [[Menopause]]
# [[Premature menopause]]
# [[Hypothalamic-pituitary dysfunction]], including
## Exercise amenorrhoea, related to excessive [[physical exercise]]
## [[Stress (medicine)|Stress]] amenorrhoea,
## [[Eating disorders]] and weight loss (obesity, [[anorexia nervosa]], or [[bulimia]])
# [[Hyperprolactinemia]] (elevated [[prolactin]] levels)
# [[Polycystic ovary syndrome]] (PCO-S)
# Androgen producing tumor (i.e [[arrhenoblastoma]])
# Intrauterine adhesions ([[Asherman's Syndrome]])
# [[Thyroid]] dysfunction
# [[Hemochromatosis]]
# Drug-induced
===Hormonal involvement===
Hypogonadotropic amenorrhoea refers to conditions where there are very low levels of serum [[FSH]] and [[LH]]. Generally, inadequate levels of these hormones lead to inadequately stimulated ovaries who then fail to produce enough [[estrogen]] to stimulate the [[endometrium]] (uterine lining), hence amenorrhoea. This is typical for conditions of pubertal delay, hypothalamic or pituitary dysfunction. In general, women with hypogonadotropic amenorrhoea are potentially fertile.
Hypergonadotropic amenorrhoea refers to conditions with high levels of [[FSH]] (and [[LH]]). FSH levels are typically in the menopausal range. This implies that the [[ovary]] or [[gonad]] does not respond to pituitary stimulation. Gonadal dysgenesis or premature menopause are possible causes. [[Chromosome]] testing is usually indicated in younger individuals with hypergonadotropic amenorrhoea.
In normogonadotropic amenorrhoea, FSH levels are in the normal range. This would suggest that the [[hypothalamic-pituitary-ovarian axis]] is functional. Amenorrhoea may be due to outflow obstruction, or abnormal ovarian regulation or excess androgens as seen in polycystic ovary syndrome.
Cushing's Disease/Syndrome can also cause amenorrhoea due to excessive amounts of cortisol in the blood stream.
==Specific types of amenorrhoea==
===Exercise amenorrhoea===
Female athletes or women who perform considerable amounts of exercise on a regular basis are at risk of developing 'athletic' amenorrhoea. It was thought for many years that low body fat levels and exercise related chemicals (such as beta endorphins and catecholamines) disrupt the interplay of the sex hormones estrogen and progesterone. However recent studies have shown that there are no differences in the body composition, or hormonal levels in amenorrheic athletes. Instead, amenorrhea has been shown to be directly attributable to a low energy availability. Many women who exercise at a high level do not take in enough calories to expend on their exercise as well as to maintain their normal menstrual cycles. [http://jap.physiology.org/cgi/content/full/84/1/37]
A second serious risk factor of amenorrhea is severe bone loss sometimes resulting in [[osteoporosis]] and [[osteopenia]]. It is the third component of an increasingly common disease known as [[female athlete triad]] syndrome. The other two components of this syndrome are [[osteoporosis]] and [[disordered eating]]. [[Awareness]] and intervention can usually prevent this occurrence in most female athletes.
=====High risk sports=====
* Cross country
* Ballet
* Track and Field
* Swimming
* Cycling
* Rowing
* Colorguard/Dance
* Diving
* Figure skating
* Gymnastics
* all other intense and strenuous sports
===Drug-induced amenorrhea===
Certain medications, particularly contraceptive medications, can induce amenorrhoea in a healthy woman. The lack of menstruation usually begins shortly after beginning the medication and can take up to a year to resume after stopping a medication. Hormonal contraceptives that [[Progestogen only pill|contain only progestogen]] like the oral contraceptive Micronor, and especially higher-dose formulations like the injectable [[Depo Provera]] commonly induce this [[side-effect]]. Recently, an [[extended cycle combined oral contraceptive pill]] which aims to purposefully induce amenorrhea (Lybrel), has been approved by the [[FDA]].
==Treatments==
Treatments vary based on the underlying condition. Key issues are problems of surgical correction if appropriate and estrogen therapy if estrogen levels are low.
For those who do not plan to have biological children, treatment may be unnecessary if the underlying cause of the amenorrhoea is not threatening to her health.
Unless receiving eggs from an [[egg donor]] or invetro fertilization, a woman is unable to conceive while she is amenorrhoeic. On the other hand, 'athletic' and drug-induced amenorrhoea has no effect on long term fertility as long as menstruation can recommence. The best way to treat 'athletic' amenorrhoea is to decrease the amount and intensity of exercise. Similarly, to treat drug-induced amenorrhoea, stopping the medication on the advice of a doctor is a usual course of action.
==External links==
*[http://www.disability.vic.gov.au/dsonline/dsarticles.nsf/pages/Menstruation_amenorrhoea?OpenDocument Disability Online's amenorrhoea page]
* [http://www.disability.vic.gov.au/dsonline/dsarticles.nsf/pages/Menstruation_athletic_amenorrhoea?OpenDocument Disability Online's athletic amenorrhoea page]
{{Diseases of the pelvis, genitals and breasts}}
[[Category:Endocrinology]]
[[Category:Gynecology]]
[[Category:Menstruation]]
[[Category:Symptoms]]
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