Polycystic ovarian syndrome (PCOS)
What is PCOS?
Polycystic ovary syndrome (PCOS) is common, affecting 15% of women of reproductive age. The cause is not well understood, although genes (family history), foetal programming, childhood obesity, the environment, high calorie intake and inactivity have been proposed in the pathogenesis.
Most of the harmful effects of PCOS such as anovulation, miscarriages, diabetes, high cholesterol and heart disease are more likely to manifest when you gain weight.
Women with PCOS are not infertile. They generally have significant number of eggs but their ovaries are disorganised. Ovulation can be random or sometimes absent. We now have a wide range of fertility treatment options to help women with PCOS conceive.
Do I have PCOS?
The diagnosis of PCOS is a clinical diagnosis supported by biochemical evidence. The Rotterdam Criteria, which is the most common method of diagnosis gives a high probability of PCOS if:
It's easy to under or over-diagnose PCOS for several reasons.
Could I have something else?
There are several endocrine conditions that mimic PCOS. These include:
Most women with PCOS have a degree of insulin resistance, which leads to elevated (1) Luteinising hormone (LH), a pituitary hormone AND (2) testosterone, a hormone secreted by the ovaries and adrenal glands. Imbalances in these hormones are responsible for the disruption in ovulation in women with PCOS.
- Resistance to insulin is defined as high insulin concentrations in association with blood glucose concentrations that are normal or high.
- In clinical practice, insulin resistance is determined by clinical signs (eg. acanthosis nigrans) and biomarkers of insulin resistance (high LH, low SHBG, impaired glucose tolerance, diabetes).
- Among women with PCOS and obesity, up to 35 percent will develop impaired glucose tolerance (“pre-diabetes”) by the age of 40, and up to 10 percent will develop type 2 diabetes.
- Insulin resistance is potentially modifiable (see below).