August 2018 Health Bulletin

Polycystic ovary syndrome in women – a common problem or is it being over diagnosed?

Polycystic ovary syndrome, more commonly known as PCOS, is often described as the most common hormone condition affecting young women. PCOS is characterised by irregular/absent menstrual cycles, clinical features of relative androgen excess (acne, excess male type hair [hirsutism] or loss of scalp hair) and/or elevated levels of androgens in the blood.

One would think this should make the diagnosis quite straight forward, particularly considering the number of research studies of PCOS that have been undertaken. However, PCOS is not a single condition but rather a cluster of symptoms and clinical findings that vary considerably. Thus, different women have different combinations of the clinical characteristics of PCOS (for example some women are hirsute whereas others are not) and different degrees of severity.

Inconsistencies and uncertainties in the diagnosis of PCOS have been highlighted by a recent study led by Marina Skiba of the Women’s Health Research Program, published in Human Reproduction Update in August 20181. The study looked at the way in which the clinical features of PCOS have been evaluated in large clinical studies that have reported on the prevalence of PCOS in different populations.

For example, hirsutism (excessive male-type body hair) is a cardinal diagnostic component for the diagnosis of PCOS. In general, a system is used to score women’s body areas according to 'hairiness' with 0=no hair and 4=full male pattern hair. This is called the Ferriman-Gallwey Score. Originally the score involved assessing 11 body areas (highest possible score 44). Subsequently a modified Ferriman-Gallwey Score including 9 body areas was developed (highest possible score 36).

When we systematically reviewed the major papers reporting the prevalence of PCOS1, we found some studies used the original Ferriman-Gallwey system and some used the modified system. Furthermore, some studies used a cut-off score of 6 and some used a cut-off score of 81. Hence there was no consistency in the approach to diagnosing hirsutism in these prevalence studies, other than they all use a score above 8 to classify a woman as hirsute.

Adding further confusion, a new Guideline for PCOS has proposed that the cut-off for diagnosing hirsutism (and therefore possible PCOS) should be a modified Ferriman-Gallwey score of greater than 5 for Han Chinese women, and a score of greater than 3 for “Caucasian” women2. A lower cut-off score for body hair for "Caucasian" versus Han Chinese women does not fit with the tendency for "Caucasian" women to normally have more facial and body hair than Chinese women.

Furthermore, a cut-off of greater than 3 would mean that the majority of women with European ancestry women would be classified as being hirsute3. This risks women with European ancestry being over-diagnosed as having PCOS- i.e. classified as having a condition that they do not have. The negative psychosocial impact of labelling women as having PCOS when they have minimal symptoms is of concern4.

Uncertainty and inconsistency in diagnosis extends to other key features of PCOS such as elevated blood androgens and polycystic ovaries. It is unclear as to whether the hormone testosterone is the best indicator of possible PCOS, or whether one of the other androgens in women may be a better diagnostic marker. It is also uncertain as to what level of testosterone or any other androgen in the blood is abnormal.

There is also uncertainty as to how many follicles (commonly called cysts) in a woman’s ovary are needed for a woman to be said to have polycystic ovaries. Previously if more than 12 follicles (cysts) were seen in an ovary on ultrasound a woman may have been considered to have polycystic ovaries5. With the increased resolution of ultrasound images, having 12 follicles in each ovary is now considered within the normal range. The recent PCOS Guideline recommends 20 or more follicles per ovary is polycystic2. Recent studies, however recommend a cut-off of 25 follicles per ovary. This needs clarification.

In summary, as stated by Skiba et al1:

"Uncertainty surrounding the diagnosis of PCOS urgently needs to be addressed in order to provide clinicians and their patients with greater diagnostic certainty, and hence reduce inappropriate labelling and the potential psychological harm that may accompany misdiagnosis."

References

  1. Skiba MA, Islam RM, Bell RJ, Davis SR. Understanding variation in prevalence estimates of polycystic ovary syndrome: a systematic review and meta-analysis. Hum Reprod Update. 2018.
  2. Teede HJ, Misso ML, Costello MF, et al. Recommendations from the international evidence-based guideline for the assessment and management of polycystic ovary syndrome. Fertil Steril. 2018;110(3):364-379.
  3. DeUgarte CM, Woods KS, Bartolucci AA, Azziz R. Degree of facial and body terminal hair growth in unselected black and white women: toward a populational definition of hirsutism. J Clin Endocrinol Metab. 2006;91(4):1345-1350.
  4. Copp T, McCaffery K, Azizi L, Doust J, Mol BWJ, Jansen J. Influence of the disease label 'polycystic ovary syndrome' on intention to have an ultrasound and psychosocial outcomes: a randomised online study in young women. Hum Reprod. 2017;32(4):876-884.
  5. Broekmans FJ, Knauff EA, Valkenburg O, Laven JS, Eijkemans MJ, Fauser BC. PCOS according to the Rotterdam consensus criteria: Change in prevalence among WHO-II anovulation and association with metabolic factors. BJOG. 2006;113(10):1210-1217.



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