2.1
Introduction
Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age.
According to the National Institute of Health (NIH) criteria, the prevalence of PCOS ranges between 6% and 10% and with utilisation of the ESHRE/ASRM consensus criteria, it is as high as 15%.
2.1.1
Clinical presentation
PCOS may appear for the first time during adolescence. The symptoms usually start in adolescence and progress gradually over time.
Some women may have some signs of hyperandrogenism during the early stage of puberty, but a clear diagnosis of the syndrome during puberty is difficult, since all the symptoms have not been fully established.
- 1.
Irregular cycles/anovulation:
- a.
Most recent guidance suggests that irregular menstrual cycles are defined as <21 or >35 days or <8 cycles in a year from the point of 3 years postmenarche to perimenopause.
- b.
Within the first 3 years postmenarche, the cycles should be >45 days and within 1 year postmenarche >90 days.
- c.
Primary amenorrhea by age 15 or >3 years postthelarche.
- d.
Secondary amenorrhea may also occur occasionally and is defined as a lack of menstrual periods for at least 6 months in a history of oligomenorrhea.
- e.
It is recognised that irregular menstrual cycles and other features of PCOS can overlap with those observed in the normal pubertal transition.
- f.
79% women with PCOS have either history of oligomenorrhea or secondary amenorrhoea.
- a.
- 2.
Signs of hyperandrogenism:
- a.
Acne, hirsutism, and male pattern baldness, are suggestive of PCO.
- b.
Hirsutism may be one of the symptoms, but not in all cases according to the Rotterdam definition.
- c.
When present, hirsutism is scored according to modified Ferriman–Gallway system.
- d.
A score equal to or greater than 4–6 is considered clinical hyperandrogenism depending on ethnicity.
- e.
Acanthosis nigricans is a profound sign of IR and is usually associated with PCO and obesity.
- a.
- 3.
Obesity:
- a.
About 40%–50% of women with PCOS are overweight.
- b.
Increased abdominal obesity and waist-to-hip ratio is correlated with reduced menstrual frequency, subfertility and insulin resistance (IR).
- c.
Women in the United States with PCOS have a higher body mass index (BMI) than their European counterparts. Anovulation and hirsutism can be exacerbated by weight gain.
- d.
Acne may be also one of the manifestations of hyperandrogenism if it persists after adolescence, while alopecia may develop in the case of severe hyperandrogenism.
- a.
2.1.2
Diagnostic criteria
- 1.
Currently there are three criteria used for the diagnosis of PCOS.
- 2.
These criteria give different weights to hyperandrogenism (biochemical and/or clinical), oligoanovulation and polycystic morphology of the ovaries assessed by ultrasound.
- 3.
The aetiology of the syndrome is unknown, and it is also associated with insulin resistance and hyperinsulinaemia, elevated Luteinising Hormone (LH) levels, raised LH/follicle stimulating hormone (FSH) ratio, and elevated anti-Mullerian hormone (AMH).
- 4.
The NIH definition relies on two criteria and does not include the ovarian morphology.
- 5.
The Rotterdam definition considers all three criteria but only two are required for the diagnosis.
- 6.
The Androgen Excess and PCOS Society definition considers hyperandrogenism as the main criterion associated with either oligoanovulation or polycystic morphology of the ovaries or both.
- 7.
However it is important to note that none of the criteria includes either AMH levels, LH/FSH ratio, or insulin resistance.
Characteristic features of three criteria have been summarised in Table 2.1 .
- 1.
Based on the many combinations of the above criteria, several phenotypes of PCOS have been recognised.
- 2.
There are four phenotypes in the Rotterdam criteria, as shown in Table 2.2 .
Table 2.2
Four phenotypes of PCOS as described in the Rotterdam criteria.
Phenotype 1
Oligo/anovulation
Hyperandrogenism: clinical hirsutism or biochemical
Polycystic ovaries
Phenotype 2
Oligo/anovulation
Hyperandrogenism: clinical hirsutism or biochemical
Phenotype 3
Hyperandrogenism: clinical hirsutism or biochemical
Polycystic ovaries
Phenotype 4
Oligo/anovulation
Polycystic ovaries
| National Institute of Health (1990) | Rotterdam (2003) | Androgen Excess and PCOS Society (2009) | |
|---|---|---|---|
| Criteria |
|
|
|
2.2
Diagnosis
The diagnosis of PCOS is made when two out of three of the following criteria are met:
- 1.
Clinical and/or biochemical evidence of excess androgen after the exclusion of other related disorders as listed in the differential diagnosis section.
- a.
Measurement of free testosterone, total testosterone measurement, and free androgen index.
- b.
Measurement of 17α-hydroxyprogesterone [to differentiate between PCOS and late onset congenital adrenal hyperplasia (CAH)].
- c.
Adrenal androgens, such as dehydroepiandrosterone sulfate (DHEAS) may be increased in PCOS; however, its importance in the diagnosis is lower, as exclusive overproduction of this is not common.
- d.
Measurement of DHEAS or Δ4-androstenedione could be considered when total or free testosterone levels are normal.
- e.
Prolactin is also mildly elevated in PCOS women.
- a.
- 2.
Oligoovulation or anovulation:
Very challenging to look for the evidence of ovulation with irregular cycles, serum progesterone >35 nmol/L is diagnostic of ovulation.
- 3.
Ultrasound appearance of the ovaries:
- a.
The Amsterdam (2003) criteria mandated the presence of >12 follicles in each ovary measuring 2–9 mm and/or increased ovarian volume (>10 mL).
- b.
In 2018, the cut-off for follicle number was raised to 20 or more in either ovary, to reflect the improvement in ultrasound technology (transvaginal scanning with a frequency band width including 8 MHz).
ESHRE evidence-based PCO guideline states the following:
“For adolescents, who have features of PCOS but do not meet diagnostic criteria, an ‘increased risk’ could be considered and reassessment advised at or before full reproductive maturity, 8 years post menarche. This includes those with PCOS features before combined oral contraceptive pill (COCP) commencement, those with persisting features and those with significant weight gain in adolescence.”
“Ultrasound should not be used for the diagnosis of PCOS in those with a gynaecological age of < 8 years (< 8 years after menarche), due to the high incidence of multifollicular ovaries in this life stage.”
- a.
- 4.
Ethnic variation:
- a.
Health professionals should also consider ethnic variation in the presentation and manifestations of PCOS, including:
- i.
a relatively mild phenotype in Caucasians;
- ii.
higher BMI in Caucasian women, especially in North America and Australia;
- iii.
more severe hirsutism in Middle Eastern, Hispanic, and Mediterranean women;
- iv.
increased central adiposity, insulin resistance, diabetes, metabolic risks, and Acanthosis nigricans in Southeast Asians and Indigenous Australians;
- v.
lower BMI and milder hirsutism in East Asians; and
- vi.
higher BMI and metabolic features in Africans
- vii.
- i.
2.2.1
Differential diagnosis
Other causes of amenorrhoea and anovulation and hyperandrogenism must be considered in the differential diagnosis. Table 2.3 shows summary of these clinical conditions.
- 1.
Thyroid dysfunction, particularly hyperthyroidism
- 2.
Nonclassic CAH-raised 17-hydroxyprogesterone
- 3.
Androgen-secreting ovarian tumours.
- 4.
Androgen-secreting adrenal tumours
- 5.
Ovarian hyperthecosis
- 6.
Cushing‘s syndrome (especially in women with severe hyperandrogenism)
- 7.
Premature ovarian failure (very raised LH, FSH, but very low oestradiol and AMH)
- 8.
Hyperprolactinaemia (high prolactin, suppressed FSH/LH/oestradiol)
- 9.
Weight-related and exercise-related amenorrhoea (very low FSH and oestradiol levels)
- 10.
Hypogonadotrophic hypogonadism (very low LH/FSH/oestradiol)
- 11.
Growth hormone disorders (acromegaly)—hirsutism and weight gain.
| Condition | Symptoms | Blood tests |
|---|---|---|
| Congenital adrenal hyperplasia |
| High 17α-hydroxyprogesterone |
| Cushing’s syndrome | Central obesity, irregular periods, hirsutism | High androgens |
| Androgen producing tumour (ovarian/Adrenal) |
|
|
| Thyroid disease |
| Abnormal thyroid and TSH values |
| Hyperprolactinaemia | Galactorrhoea | High prolactin levels, |
| Weight-related/exercise- related amenorrhoea | Amenorrhea | Suppressed levels of FSH, LH, and oestradiol |
| Hypogonadotrophic hypogonadism | Amenorrhea | Suppressed levels of FSH, LH, and oestradiol |
| Hypothalamic amenorrhea |
| Low FSH, LH, and oestradiol |
| Primary ovarian insufficiency | Hot flashes | High FSH, LH, and low oestradiol |
| Acromegaly |
|
|
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