Four Different Types of PCOS
By Dr. Kate Dudek
PCOS (Polycystic Ovary Syndrome) is the most common hormonal condition affecting women of reproductive age. Incidence is thought to be between 4-10%.
Diagnosis of PCOS is complicated by the fact that it is likely to be a spectrum of disorders that fall under the same broad category. It is widely accepted that the presence of polycystic ovaries in isolation is an insufficient basis on which to form a diagnosis; in fact, it is possible to have normal ovaries and still be diagnosed with PCOS.
In 2003 a consensus in Rotterdam categorised PCOS into four different phenotypes.
Classic polycystic ovary PCOS
Chronic anovulation (lack of ovulation)
Hyperandrogenism (excessive levels of the male sex hormones)
Classic non-polycystic ovary PCOS
Non-classic ovulatory PCOS
Regular menstrual cycles
Non-classic mild/normoandrogenic PCOS
Most clinical guidelines, including those issued by the National Institute of Health and the Rotterdam consensus workshop, state that for a diagnosis of PCOS, patients should present with at least two out of three of the main symptoms. Each of these symptoms can vary in severity and specifics. When considering therapy for PCOS, it is important to consider the specific symptoms and tailor a personalised treatment plan accordingly.
Menstrual irregularities most frequently involve anovulation, or having a menstrual cycle without ovulation. Women who experience anovulation have a greater chance of developing associated metabolic symptoms, such as insulin resistance. This puts them at higher risk of diabetes type 2 and cardiovascular disease, which can be very serious if left untreated. Women with irregular cycles will probably also have high circulating levels of luteinising hormone.
Hyperandrogenism is one of the cardinal features of PCOS, however, in isolation is still not sufficient for a positive diagnosis. Hirsutism and acne are two of the major clinical markers of hyperandrogenism; although male-pattern hair loss and a type of hyperpigmentation, known as acanthosis nigricans, have also been well documented. Biochemically, confirmation of hyperandrogenism usually comes from measuring the levels of circulating testosterone in the blood.
Polycystic ovaries are not essential for a diagnosis of PCOS. Follicular cysts are very common, particularly during puberty. This does complicate the diagnosis of PCOS. General consensus is that if each ovary contains more than 12 follicles, which are between 2-9 mm in size, and ovarian volume exceeds 10ml, then PCOS should be considered.
Recent work has suggested that some people are born with heightened levels of a particular hormone called anti-Müllerian hormone, and this seems to predispose them to PCOS-like symptoms in adulthood. It is also thought that although PCOS is typically diagnosed in adulthood, some children might have the condition. Unfortunately, symptoms can be masked by normal pubertal development events as it can take up to two years for the menstrual cycle to become regular.
- El Hayak, S, et al. “Poly Cystic Ovarian Syndrome: An Updated Overview.” Frontiers in Physiology, vol. 7, 5 Apr. 2016, p. 124., doi:10.3389/fphys.2016.00124.
- Rotterdam ESHRE/ASRM-Sponsored PCOS Consensus Workshop Group. “Revised 2003 Consensus on Diagnostic Criteria and Long-Term Health Risks Related to Polycystic Ovary Syndrome.” Fertility and Sterility, vol. 81, no. 1, Jan. 2004, pp. 19–25.
- “How Do Health Care Providers Diagnose PCOS?” National Institute of Health, www.nichd.nih.gov/health/topics/pcos/conditioninfo/diagnose. Last Reviewed Date 31/1/2017.