What Is PCOS?
Polycystic ovary syndrome (PCOS) is a common hormonal disorder that can impair a woman’s ovulation, menstrual regularity and fertility. Found in 5-10% of reproductive aged women regardless of race or ethnicity, PCOS is the most common hormone disorder in adult women.
PCOS is also the most common cause of infertility arising from irregular ovulation. In addition to infertility, patients with PCOS may also experience abnormal sugar and insulin metabolism as well as higher risks of certain cardiovascular risk factors, including elevated lipids (cholesterol), type 2 diabetes and uterine cancer. These risks make it even more important to make an accurate diagnosis of PCOS, even in women who are not attempting to conceive.
How Is PCOS Diagnosed?
The diagnosis of PCOS is based on a combination of symptoms and physical findings: (1) irregular ovulation and menstrual cycles; (2) increased hair growth (hirsutism), acne, or other signs of male hormone excess (hyperandrogenism); and/or (3) the appearance of multiple small ovarian cysts (polycystic ovarian morphology) on ultrasound examination (see figure). New diagnostic criteria now require only two of the above findings to be suggestive of PCOS. However, additional hormone testing must also be performed to rule out other hormonal imbalances that my present with similar symptoms.
PCOS and Infertility
PCOS is the major cause of irregular ovulation, contributing to 30-40% of amenorrhea (absence of periods for at least six months or three consecutive cycles), and 90% of oligomenorrhea (irregular periods greater than 35 days apart). PCOS is the most common cause of infertility arising from disordered ovulation.
Insulin Resistance and PCOS
Insulin resistance is a common feature of women with PCOS, resulting in excessive insulin levels in response to carbohydrates. This form of insulin resistance and insulin elevation (hyperinsulinemia), in turn, appears to worsen the symptoms of PCOS: aggravating ovulatory irregularity, hirsutism and excess androgen production. According to the World Health Organzation (WHO) guidelines, patients with PCOS should undergo a special blood sugar screening test, the two-hour oral glucose tolerance test (OGTT) to screen for abnormal carbohydrate and insulin metabolism.
Approximately 35- 50% of women with PCOS are overweight to obese, and this can further worsen the degree of insulin resistance. In these overweight patient, weight loss of even 5% of initial body weight can significantly improve pregnancy rates and PCOS symptoms. In addition, many clinical studies have demonstrated improvements in hyperandrogenism, ovulation and pregnancy rates with the addition of an insulin sensitizing medication called metformin. Metformin is currently FDA approved for treatment of type II diabetes, but has been increasingly applied in PCOS patients. In some studies, metformin has been shown to increase the rates of spontaneous ovulation, decrease androgen levels and improve ovulation rates even in women who are resistant to common ovulation induction agents. Before beginning metformin, patients are carefully screened to decrease the risk of minor and rare major side effects of the medication.
Treatment of PCOS
Treatment regimens should be tailored to the patient’s clinical picture, and many include a combination of medications and/or surgery. Women with irregular ovulation wishing to conceive can begin oral or injectable medications to induce ovulation. Common medications include clomiphene citrate and gonadotropins. However, PCOS patients are at higher risk of excessive ovarian and hormonal response to ovulation induction, a phenomenon called ovarian hyperstimulation syndrome (OHSS). Therefore, PCOS patients who are undergoing fertility treatment should be monitored carefully for symptoms, ovarian cysts and enlargement throughout the process.
PCOS and In Vitro Fertilization (IVF)
In vitro fertilization in PCOS patients can be highly effective, with cycle pregnancy rates in excess of 50% in young women. However, some studies have demonstrated that although PCOS women generate a greater number of oocytes (eggs) during stimulation for IVF, there may be decrease egg quality. In addition, PCOS patients appear to have a slightly increased rate of spontaneous miscarriage.