Anovulatory cycle
1421176
211811128
2008-05-12T05:47:21Z
Smundy
5705353
adding references section
The '''anovulatory cycle''' is a [[menstrual cycle]] characterized by varying degrees of menstrual intervals and the absence of [[ovulation]] and a [[luteal phase]]. In the absence of ovulation, there will be [[infertility]].
===Patterns===
While the normal [[menstrual cycle]] in the [[human]] typically lasts 4 weeks (28 days, range 21-35 days) and consists of a [[follicular phase]], [[ovulation]], and a [[luteal phase]], followed by either [[menstruation]] or [[pregnancy]], the anovulatory cycle has cycle lengths of varying degrees. In many circumstances, menstrual intervals are prolonged exceeding 35 days leading to [[oligomenorrhea]] (cycle >35- 180 days interval), or even longer, [[amenorrhea]]. In other cases, menstruation may be fairly regular ([[eumenorrhea]]), or more frequent (intervals < 21 days), or there may be a loss of menstrual pattern ([[menorrhagia]], [[dysfunctional uterine bleeding]]).
===Estrogen breakthrough bleeding===
Normal menstrual bleeding in the ovulatory cycle is understood as a result of a decline in [[progesterone]] due to the demise of the [[corpus luteum]]. It is thus a '''''progesterone withdrawal bleeding'''''. As there is no progesterone in the anovulatory cycle, bleeding is caused by the inability of [[estrogen]] - that needs to be present to stimulate the [[endometrium]] in the first place - to support a growing endometrium. Anovulatory bleeding is hence termed '''''estrogen breakthrough bleeding'''''.
===Risks===
#[[Anemia]]
#[[Bone density]] loss <ref>Park KH, Song CH. "Bone mineral density in premenopausal anovulatory women." ''J Obstet Gynaecol'', 1995 Feb;21(1):89-97.[http://www.ncbi.nlm.nih.gov/pubmed/8591116]</ref>
#[[Endometrial cancer]]
#[[Infertility]]
===Diagnosis===
A physician needs to investigate the cause of anovulation. Common causes are:
#[[Polycystic ovary syndrome]]
#[[Hypothalamic dysfunction]]
#[[Perimenopause]]
#[[Ovulatory dysfunction]]
#[[Thyroid]] disorders
#[[Hyperprolactinemia]]
With excessive or prolonged bleeding the diagnosis has to be made by a physician on a speedy basis. Other causes of [[gynecological bleeding]] need to be excluded, specifically bleeding related to [[pregnancy]], [[leiomyoma]], and [[cancer]] of the [[cervix]] or [[uterus]].
===Management===
Women who don't ovulate and who want to get pregnant need a medical work-up to find out why they don't ovulate. Often drugs are given to induce ovulation, including oral medication such as [[clomiphene]] or injectable medications.
In patients who do not want to get pregnant anovulation can be managed with the use of cyclic [[progesterone]] or [[progestin]] supplementation or use of [[hormonal contraception]].
===See also===
*[[Menstrual cycle]]
*[[Ovulation]]
==Notes==
{{reflist}}
[[Category:Reproductive system]]