Diagnosing PCOS

How is PCOS diagnosed?

According to the 2023 International Evidence-Based Guidelines for the Assessment and Management of PCOS, an individual meets the diagnostic criteria for PCOS if they have at least two of: hyperandrogenism, ovulatory dysfunction and/or polycystic ovaries.

t is estimated that up to 70% of individuals affected by PCOS remain undiagnosed.[1] In this article we explore the issues around Diagnosing PCOS.

In practical terms, when engaging with a primary care physician (PCP), individuals are often explicitly requested to limit their visit to discussing a single symptom. For individuals with PCOS they therefore may only discuss the single symptom that is having the most severe impact on their quality of life at that time. For many of the most common symptoms of PCOS, including irregular periods, acne and heavy bleeding, the PCP will often then prescribe oral contraceptives (OCs) without making a formal diagnosis of PCOS.[2]

Once taking any kind of hormonal medication, it is impossible to get an accurate picture of your body’s natural hormone levels. It can take up to six weeks for the medication to clear your system to be able to reliably test.

Whilst OCs may provide relief from certain PCOS symptoms, hormonal medication is effectively masking the symptoms without addressing the core condition. For example, the cycle you experience whilst taking OCs is not the same as a regular menstrual cycle and the bleeding you experience is a “withdrawal bleed” rather than a natural period.[3] For those seeking to start a family in the near-term, OCs inherently affect fertility and it normally takes several months to a year to conceive (although can happen immediately).[4]

OCs are commonly believed to lead to weight gain, a troubling issue for those already struggling to maintain a healthy weight. The progestin component in many combined hormonal contraceptives (CHCs) can increase appetite for some individuals and therefore lead to weight gain.[5]

OCs also bring a risk of side-effects, some of which may feel similar to PCOS symptoms, including breakthrough bleeding, headaches and bloating.[6] The more serious side-effects associated with the pill – blood clots, cardiovascular disease and liver disorders – may be particularly troubling to those with an underlying increased risk of those conditions due to their PCOS condition.[7]

Doctors will often prescribe up to 3 different types of OCs over a period of several years before seeking other forms of care and, in some cases, are mandated to do so by the healthcare insurer. The net effect of this can be to extend the time to achieve a formal diagnosis and/or exhaust the individual navigating the healthcare system so that they give up on getting a diagnosis.[8]

Physicians may also informally diagnose individuals based on their perception of the “PCOS look”, a subjective set of assumptions on the typical appearance of an individual with PCOS. This might typically include assumptions about body mass index (BMI) and hirsutism and inherently excludes a significant proportion of individuals with the condition.[9]

Historically, the gold standard in PCOS diagnosis involved using a pelvic ultrasound, where a transducer is inserted into the vagina and sound waves create images of the organs in the pelvic area.[10] The images would be used to detect features such as an increased number of antral follicles (the “string of pearls”), a higher than normal ovarian volume or multiple small cysts within the ovaries (“polycystic ovaries”).[11]

However, one study estimated that the proportion of women with PCOS who exhibit polycystic ovaries could be as low as 17-33%.[12] Relying solely on pelvic ultrasound would therefore lead to missed diagnosis in the majority of cases (i.e., 67-83%). In addition, it is only recently that quantified thresholds for ovarian volume and follicle number have been specified (10cm³ and 12 or more follicles measuring 2-9mm per ovary).[13] The other challenge with pelvic ultrasound is that is it is viewed as “non-invasive” despite the transducer being inserted into the vagina; this procedure can be uncomfortable and may be particularly troubling for individuals who are not sexually active.

One of the common pathways for individuals to discover that they have PCOS is during the initial assessment for fertility treatment when some form of pelvic ultrasound is routinely conducted. However, in some cases the physician may not even make the individual aware that a diagnosis of PCOS has been made whilst potentially proceeding with a modified medication protocol.[14]

In 1990, the National Institutes of Health (NIH) specified that a diagnosis of PCOS required both:[15]

Oligomenorrhea; irregular or infrequent periods indicating a lack of regular ovulation; and
Hyperandrogenism, clinical signs of elevated androgens such as hirsutism or high androgen levels as measured by blood tests.

In 2003, the Rotterdam criteria were established as diagnostic guidelines for PCOS, requiring at least two of the following three conditions:[16]

Oligomenorrhea;
Hyperandrogenism; and/or
Polycystic ovaries, as seen on an ultrasound.

In 2023, new evidence-based guidelines for the assessment and management of PCOS were released as the culmination of an international collaboration between 100+ clinical experts.[17] The guidelines were an update to the Rotterdam criteria, requiring at least two of:[18]

Biochemical/clinical hyperandrogenism.
Ovulatory dysfunction; and/or
Polycystic ovaries on ultrasound or elevated anti-müllerian hormone (AMH) levels.

Ovulatory dysfunction (OD) is defined as:[19]

Within 1-3 years post menarche (onset of menstruation), less than 21 days, more than 45 days or more than 90 days for any cycle; and
After 3 years post menarche, less than 21 days, more than 45 days, less than 8 cycles per year or more than 90 days for any cycle.

Irregular cycles are viewed as normal during the first year post menarche as part of the puberty transition period.

Biochemical hyperandrogenism (HA) is defined as:^[20]

Elevated total and free testosterone level or free androgen index (FAI = 100 x total testosterone/SHBG), with free testosterone have the highest specificity at c.93%.

Critically, there is significant debate on what the normal range of testosterone should be defined as. There is also a practical constraint as clinicians typically test hormones on day 3 of a menstrual cycle and this may be difficult to pinpoint for this with absent or irregular periods. Even when an individual demonstrates a very high testosterone level on more than one test, the test results may be dismissed by their clinician.[21]

Clinical HA is defined as:^[22]

Prescence of hirsutism (as predictive indicator); and/or
Prescence of female pattern hair loss and acne (as weak indicator).

These measures still rely on subjective judgements of the healthcare professional and do not take into account the significant measures some individuals go to in addressing or masking these symptoms.

Polycystic ovaries (PCO) are defined as:^[23]

Follicle number per ovary (FNPO) of at least 20 in at least one ovary;
Follicle number per cross-section (FNPS) of at least 10 in at least one ovary; and/or
Ovarian volume (OV) of at least 10ml.

Elevated AMH is defined as:[24]

Elevated levels of serum AMH (in adults only).

Similarly to HA, there is significant debate on what the normal range of AMH should be defined and a practical constraint to pinpointing “day 3” of the cycle.

Despite these recent advances, PCOS often remains a diagnosis of exclusion and clinicians may run additional tests to rule out a variety of conditions including:[25]

Pregnancy;
Thyroid dysfunction, either overactive (hypothyroidism) or underactive (hyperthyroidism) thyroid gland, the gland responsible for controlling your metabolism;[26]
Hyperprolactinemia, elevated levels of prolactin, the hormone responsible for breast development and lactation;[27]
Nonclassical congenital adrenal hyperplasia (NC-CAH), inherited condition where there is an elevated production of androgens (but normal levels of aldosterone);[28]
Hypothalamic amenorrhea, cessation of menstruation due to disruption to the functioning of the hypothalamus due to excessive exercise, stress and/or malnutrition;[29]
Primary ovarian insufficiency (POI), where the ovaries stop functioning before the age of 40;[30]
Androgen-secreting tumor, benign or malignant tumors in the adrenal glands;[31]
Cushing syndrome, caused by sustained exposure to elevated levels of cortisol;[32] and
Acromegaly, rare condition where the pituitary gland produces high levels of growth hormone causes bones, organs and other tissues to grow.[33]

A number of these conditions, including thyroid dysfunction[34] and hyperprolactinemia,[35] are more prevalent in individuals with PCOS.

There are a variety of systemic factors that can confound, delay or prevent diagnosis, including:

Reluctance to seek and advocate for care on the part of the individual due to stigma or other societal norms;
Structural barriers in communication between an individual and their care provider, e.g., only being allowed to discuss one symptom per appointment;
Systemic gender bias in healthcare where symptoms may be dismissed or treated as psychosomatic (all in your head);
Structural barriers in dissemination of up-to-date information, i.e., of 2023 guidelines;
Widespread use of hormonal medications, including oral contraceptives, topical treatments, etc;
Common exposure to endocrine-disrupting chemicals (EDCs) through environmental hazards, workplace exposure or cosmetics/chemicals in the home;
Confounding factors relating to an individual’s life-stage, e.g., overlap in symptoms with adolescence or perimenopause; and
Confounding factors relating to other conditions, whether co-morbid or mis-diagnosed, such as endometriosis and uterine fibroids.

Want to learn more about the core features of PCOS? Check out the sections on Androgen Excess, Ovulatory Dysfunction and Polycystic Ovaries.

[1] https://www.who.int/news-room/fact-sheets/detail/polycystic-ovary-syndrome

[2] Neuraura End-User Interviews

[3] https://www.rush.edu/news/understanding-birth-control

[4] https://www.bu.edu/sph/news/articles/2021/how-long-will-it-take-you-to-conceive-after-stopping-birth-control/

[5] https://my.clevelandclinic.org/health/treatments/24838-progestin

[6] https://www.mayoclinic.org/tests-procedures/combination-birth-control-pills/about/pac-20385282

[7] https://www.mayoclinic.org/tests-procedures/combination-birth-control-pills/about/pac-20385282

[8] Neuraura End-User Interviews

[9] Neuraura End-User Interviews

[10] https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/pelvic-ultrasound

[11] https://pmc.ncbi.nlm.nih.gov/articles/PMC9210988/

[12] https://pmc.ncbi.nlm.nih.gov/articles/PMC4341818/