Polycystic ovary syndrome

📅 November 2, 2024 ✍️ By Randy Thompson ⏱️ 4 Mins Read 🗂️ Blog 🕒 Last updated: November 5, 2024

Laparoscopic view showing a polycystic ovary: PCOS is a leading cause of female subfertility (Photograph: SPL)

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Polycystic ovary syndrome (PCOS), a leading cause of female subfertility, is common, affecting about 5-10% of women of reproductive age in the UK. The cause remains unknown. There is often an increased preponderance in family members, but it is likely that both environmental factors and genetics play a part.

1. Clinical features
Signs and symptoms of PCOS include:

Infrequent or absent periods
Infertility or subfertility
Heavy menstrual bleeding
Hirsutism
Acne
Male pattern hair thinning
Metabolic syndrome

Most women with PCOS are obese and/or have increased insulin resistance. The resulting hyperinsulinaemia stimulates ovarian androgen production. This is subsequently converted to free testosterone and gives rise to the clinical features associated with PCOS. High levels of androgen interfere with the development and release of eggs, and cysts may form on the ovaries. Systemically testosterone causes acne, hirsutism and thinning hair.

Differential diagnosis
Thyroid dysfunction Cushing's syndrome Congenital adrenal hyperplasia Hyperprolactinaemia Androgen-secreting tumours

2. Presentation

There are many reasons a woman with PCOS may present to the GP. Some may be troubled by heavy, irregular periods, persistent acne or hirsutism; others may struggle to lose weight. Some might not present until trying to conceive, when infrequent or absent periods from anovulatory cycles commonly result in reduced fertility.

3. Diagnosis
The Rotterdam criteria for the diagnosis of PCOS¹ state that once other aetiologies are excluded, two of three findings must be present for the diagnosis to be made (see box).

Rotterdam criteria

1. Irregular or absent ovulation.

2. Clinical or biochemical signs of hyperandrogenism.

3. Enlarged ovaries containing at least 12 follicles each.

Other conditions, such as androgen-secreting tumours or Cushing's syndrome, must be ruled out. Polycystic ovaries with normal ovarian function and without hyperandrogenism should not be considered PCOS without further investigation.

It is important to note that while about one in four women have polycystic ovaries on an ultrasound scan, only a proportion of these have PCOS, so pelvic ultrasound alone is not appropriate for diagnosis.

Among experts in obstetrics and gynaecology, PCOS is commonly viewed as a condition encompassing a wide spectrum of disorder and overlapping with normality. This suggests that some symptom-specific treatment may be appropriate even if a diagnosis of PCOS cannot be made.

As part of the diagnostic process, simple blood tests should be performed - they can help to identify features of PCOS and rule out other causes.

When menstruation is occurring, bloods are best done in the first week of the cycle to aid interpretation of results.

FSH, SHBG and testosterone should be tested, alongside prolactin and thyroid function.

A pelvic ultrasound is usually also requested.

4. Differential diagnosis
It is important to consider the differential diagnosis. While a low-grade rise in testosterone, with other relevant features, is suggestive of PCOS, an excessively raised level may result from an androgen-secreting tumour, congenital adrenal hyperplasia or Cushing's syndrome.

For all patients diagnosed with PCOS, BP, height and weight should be recorded and BMI calculated. Further screening blood tests may be appropriate. These are particularly important in someone who is overweight and over 40 years of age, or who has a family history of type-2 diabetes.

In this group, a fasting lipid profile and oral glucose tolerance test are recommended to help identify any associated metabolic syndrome. PCOS alone appears to be an independent risk factor for type-2 diabetes, so an annual fasting glucose test should be considered for all patients.²

5. Management
Treatment for PCOS should be tailored to patient need. For infrequent periods or fertility concerns, optimising weight is often sufficient to stimulate ovulation and improve cardiovascular risk factors.

Lifestyle advice is the first-line therapy. Importantly, a low glycaemic index diet has been shown to be the most beneficial in reducing weight and cardiovascular risk and improving cyclicity. The addition of metformin to such a diet can optimise its potential by reducing insulin resistance.³ In some cases, anti-obesity drugs may be appropriate.⁴

Hormonal methods are useful to help regulate periods in a patient not trying to conceive. The combined oral contraceptive (COC) has historically been used, but it is important to bear in mind that it can alter the lipid profile and increase thrombo-embolic risk in patients with a high BMI.

Cyclical progesterones may have a role in triggering a regular withdrawal bleed for women with PCOS who have fewer than four periods a year and are unable to take the COC.

In patients with normal or borderline BMI who are trying to conceive, anti-estrogen therapy may be used to help stimulate ovulation. Frequently this is managed by secondary care because careful consideration must be paid to the risks associated with ovarian hyperstimulation. Early specialist referral is appropriate in patients with persistent conception difficulty, especially if aged over 35 years, regardless of weight.

Patients with PCOS are most often troubled by acne and hirsutism. It is important to note that while these androgenic symptoms are unlikely to cause serious long-term physical complications, they are distressing to the patient and should be addressed.

Options include topical or systemic antibiotics and drying agents for acne, and hair removal using waxing or electrolysis techniques, depilatory creams or laser therapy. Possible medical management steps to consider include topical eflornithine or, in the absence of contraindications, co-cyprindiol.