Pathogenesis
Polycystic ovaries develop when the ovaries are stimulated to produce excessive amounts of androgenic hormones, in particular testosterone, by either one or a combination of the following (almost certainly combined with genetic susceptibility):
the release of excessive luteinizing hormone (LH) by the anterior pituitary gland
through high levels of insulin in the blood (hyperinsulinaemia) in women whose ovaries are sensitive to this stimulusA majority of women with PCOS have insulin resistance and/or are obese, which is a strong risk factor for insulin resistance, although insulin resistance is a common finding among women with PCOS in normal-weight women as well. Elevated insulin levels contribute to or cause the abnormalities seen in the hypothalamic-pituitary-ovarian axis that lead to PCOS. Hyperinsulinemia increases GnRH pulse frequency, which in turn results in an increase in the LH/FSH ratio increased ovarian androgen production; decreased follicular maturation; and decreased SHBG binding. Furthermore, excessive insulin increases the activity of 17α-hydroxylase, which catalyzes the conversion of progesterone to androstenedione, which is in turn converted to testosterone. The combined effects of hyperinsulinemia contribute to an increased risk of PCOS.Adipose (fat) tissue possesses aromatase, an enzyme that converts androstenedione to estrone and testosterone to estradiol. The excess of adipose tissue in obese women creates the paradox of having both excess androgens (which are responsible for hirsutism and virilization) and excess estrogens (which inhibit FSH via negative feedback).The syndrome acquired its most widely used name due to the common sign on ultrasound examination of multiple (poly) ovarian cysts. These "cysts" are in fact immature ovarian follicles.
Myo-inositol reduces the amount of gonadotropins and the length of controlled ovarian hyperstimulation in women undergoing in vitro fertilization. A 2011 review found not enough evidence to conclude any beneficial effect from D-chiro-inositol. There is insufficient evidence to support the use of acupuncture, current studies are inconclusive and theres a need for additional randomized controlled trials. Treatment
PCOS has no cure, as of 2020. Treatment may involve lifestyle changes such as weight loss and exercise. Birth control pills may help with improving the regularity of periods, excess hair growth, and acne. Metformin and anti-androgens may also help. Other typical acne treatments and hair removal techniques may be used. Efforts to improve fertility include weight loss, clomiphene, or metformin. In vitro fertilization is used by some in whom other measures are not effective. Epidemiology
PCOS is the most common endocrine disorder among women between the ages of 18 and 44. It affects approximately 2% to 20% of this age group depending on how it is defined. When someone is infertile due to lack of ovulation, PCOS is the most common cause and could guide to patients diagnosis. The earliest known description of what is now recognized as PCOS dates from 1721 in Italy. The prevalence of PCOS depends on the choice of diagnostic criteria. The World Health Organization estimates that it affects 116 million women worldwide as of 2010 (3.4% of women). Another estimate indicates that 7% of women of reproductive age are affected.