Polycystic ovarian syndrome (PCOS) is an exceedingly common reproductive disorder, affecting an estimated 10% to 15% of reproductive-age women. The diagnosis of PCOS is a clinical one. In 2003, the ESHRE/ASRM consensus conference redefined PCOS as the presence of at least two out of the three following clinical criteria:

  1. Irregular menstrual cycles
  2. Evidence of extra male hormones, as determined either by clinical examination or by blood tests
  3. Ultrasound demonstrating ovaries with numerous small follicles (PCO-appearing ovaries)

Previously, only patients with irregular menstrual cycles were thought to have PCOS, so the expansion of this definition has led to some confusion among healthcare providers. Other features commonly associated with PCOS include obesity, insulin resistance, borderline diabetes, skin tags, and a velvety discoloration on the nape of the neck and inner thighs called acanthosis nigricans. The topic of PCOS can fill an entire book. In fact, several books have been devoted to this subject. Although this condition was originally described by Drs. Stein and Leventhal in 1935, our understanding of PCOS has advanced significantly in the last decade.

Originally, PCOS was thought to be an anatomical problem in which a thickened coating around the ovary prevented ovulation. It is now agreed that PCOS represents a hormonal imbalance. At the heart of this disorder is insulin resistance. Insulin is a hormone secreted by the pancreas and induces your body to store the sugar circulating in the bloodstream. Individuals who fail to produce insulin as a result of an autoimmune disorder require insulin therapy to maintain normal blood sugar levels. These patients are referred to as having insulin dependent diabetes (also known as type 1 diabetes).

The majority of patients with impaired glucose metabolism actually suffer from insulin resistance rather than insulin deficiency. That is, the cells of their bodies are not sensitive to the effects of insulin, so they require ever-increasing amounts of insulin to be released from the pancreas until appropriate blood levels of glucose are obtained. These patients are commonly referred to as having non-insulin-dependent diabetes (also known as type 2 diabetes or adult-onset diabetes). Despite the name of the disease, persons with type 2 diabetes may require insulin injections to maintain normal glucose levels depending on their degree of insulin resistance.

Insulin resistance is likely a genetic disorder. This explains why adult-onset type 2 diabetes is so prevalent in certain families and in certain ethnic groups. In patients who are insulin resistant, the excessive levels of insulin affect not only their metabolism, but also their reproductive system. Insulin directly affects the release of reproductive hormones from the pituitary gland and directly stimulates ovarian production of male hormones. Thus the presence of excess insulin results in a local environment that is not conducive to follicle growth. The multiple follicles that fail to mature produce excessive male hormones, resulting in acne and abnormal hair growth commonly encountered in women with PCOS. Obesity itself also increases insulin resistance, so patients can find themselves trapped in a vicious cycle of irregular cycles and worsening weight gain. Women who have always had regular periods during their entire life but suddenly gain significant weight may frequently resemble patients with PCOS. In these cases, weight loss by itself may restore normal cycles and improve fertility.

Kristin comments:

Looking back at my early menstrual cycles, it should have come as no surprise that my reproductive system was not in normal working order. I had extremely heavy periods, but they were never regular. Sometimes I would go months without a period. I didn’t think much about it until my husband and I started trying to get pregnant. I went off the pill and got a period about 2 months later. I began charting my basal body temperature and discovered that I was not ovulating. I decided to be proactive and saw my OB, who confirmed that I have PCOS. This diagnosis was further confirmed at my first RE visit. The doctor did a transvaginal ultrasound, which showed that both of my ovaries were covered with many small follicles. I did meet the clinical criteria for diagnosing PCOS, but I did not exhibit any of the outwardly apparent features—obesity, skin tags, acanthosis nigricans.