Polycystic ovarian syndrome (PCOS) is a condition that affects approximately 20% of patients with ovulatory dysfunction. The name refers to the anatomic appearance of the ovaries of affected women. When seen on ultrasound polycystic ovaries measure about 1.5 times the size of ovaries of women who cycle monthly.
The “cysts” refer to the ovarian follicles which, instead of appearing in a random distribution throughout the ovary, are lined up around the periphery like a string of beads. The “poly” comes from the excessive number of follicles: whereas a normal, cycling ovary in a young woman contains about 7 – 8, the number of follicles in a PCO patient can be more than 20.
In addition to the excessive number of follicles the PCOS patient suffers from oligo or anovulation and, often, increased androgen (male hormone) activity. Anovulation results in irregular or absent periods and infertility. Increased androgens may cause facial acne and oiliness and facial and body hirsutism. In addition to this hormone imbalance, insulin resistance is common and can be associated with obesity, Type 2 diabetes, and high cholesterol levels. However not all PCOS patients present with all these findings. PCOS is a spectrum, symptoms vary greatly, and some women are more affected than others. In fact, in 2003 a consensus workshop sponsored by the European and American reproductive societies (ESHRE and ASRM) concluded that 2 of the 3 findings (ovulatory dysfunction, excess androgen activity, sonographic appearance of polycystic ovaries) must be present for the diagnosis of PCOS.
PCOS is diagnosed with a careful menstrual history, hormone tests – specifically FSH, estradiol, LH and the male hormones testosterone and androstenedione, and an ovarian sonogram.
Additional tests may also be indicated such as a glucose tolerance test, a lipid profile, and additional tests of androgen activity. A laparoscopy is not required for diagnosis but, if it is performed for other reasons, polycystic ovaries will appear enlarged with characteristic thick smooth white capsules.
PCOS is a heterogeneous disorder and the cause or causes are unknown. There is a presumed genetic component to the condition and there are clusters in families. Polycystic ovaries develop when the ovaries are stimulated to produce excessive amounts of androgens via either increased secretion of LH from the pituitary or by an increased amount of circulating insulin – or from a combination of the two mechanisms. The excess amounts of circulating androgens decrease maturation of ovarian follicles. The hormonal “imbalance” and the surplus of immature follicles produce a steady – state situation in which the ovaries do not “cycle” and pregnancy is unlikely to occur without medical intervention.