From PCOS to PMOS – what nurses need to know

GP with gynaecology specialism Dr Mehreen Ali Khan provides an update for nurses in primary care on the diagnosis and management of polycystic ovary syndrome – now officially renamed polyendocrine metabolic ovarian syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in reproductive age, affecting 1 in 8 women, with a likely higher prevalence in South Asian and Mediterranean populations. Up to 70% of cases may remain undiagnosed.

It was recently announced at the European Congress of Endocrinology that the name for the condition has officially been changed to polyendocrine metabolic ovarian syndrome (PMOS), following agreement by international societies and patient groups.

The new name better reflects the multisystemic effects of this condition including metabolic, mental, skin, cardiovascular and reproductive health.

This article outlines key practical points to support improved recognition and treatment of this debilitating condition.

Note that current UK best practice for diagnosis and management is to follow the 2023 international guidelines on PCOS developed by Monash University experts and endorsed by the Royal College of Obstetrics and Gynaecology (RCOG). NICE is in the process of developing guidance due to be released in December 2026. All these organisations will be adopting the new name PMOS from now on.

PMOS is a multisystem condition underpinned by insulin resistance

PMOS (formerly PCOS) is now understood to be a complex, long-term condition with metabolic, reproductive, dermatological, cardiovascular and psychological sequelae.

Insulin resistance is considered the key mechanism driving the hormonal dysfunction.

Diagnosis is principally based on clinical history

Under the current PCOS guidance, diagnosis can be made based on both:

Irregular menstrual cycles plus
Clinical or biochemical hyperandrogenism.

This means many patients can be potentially diagnosed clinically without the need for further investigations or ultrasound.

However, if the patient presents only with irregular menstrual cycles, or hyperandrogenism, further tests can be done in adults – specifically:

Ultrasound scan for polycystic ovarian morphology or
Blood test to check for raised anti-Müllerian hormone (AMH); however, AMH can be affected by factors such as age, BMI, and access to testing limited in primary care.

Irregular cycles need to be defined properly

Menstrual irregularity varies by years since menarche; adolescent diagnosis is difficult because irregular periods and acne are often physiological.

The definition of irregular cycles is summarised in the box below.

Remember that any irregularity in the first-year post-menarche is considered normal, as part of the pubertal transition.

It is also important to understand that gynaecological maturity is only reached 8 years after menarche – therefore it can be difficult to diagnose in this cohort of patients. Current guidance is to record patients as ‘at risk’ of PCOS (now PMOS) and reassess regularly.

Current PCOS diagnosis criteria – definition of irregular cycles

Irregular cycles are defined by any of the following:

1 to <3 years post menarche: <21 or >45 days.
3 years post menarche to perimenopause: <21 or >35 days.
Less than 8 cycles per year.
1 year post menarche: >90 days for any one cycle.
Primary amenorrhea by age 15 or >3 years post breast development.

Clinical hyperandrogenism should be assessed carefully

Hirsutism

Patients can be asked to fill out the Ferriman–Gallwey score. A score of 4-6 is classed as significant, however this can be ethnicity dependent.

Acne

Acne is assessed as per the Primary Care Dermatology Society (PCDS) acne guidelines.

Hair loss

Degree of female-pattern hair loss should be assessed by use of the Ludwig Scale, which includes Stages 1 to 3 – principally based on the level of frontal parting separation. Stage 2 is classed as clinically significant.

Biochemical testing

This is only required if clinical hyperandrogenism is not definitive.

Serum testosterone is the most useful initial test.

If patients are already on the combined oral contraceptive pill (COCP) they must stop taking it at least 3 months before this test (the COCP increases SHBG and reduces gonadotrophin-dependent androgen production).

If testosterone is normal, but there is still clinical concern, further tests may include the following:

Androstenedione
DHEAS (dehydroepiandrosterone sulfate)

However, if considering the above blood tests, referral to Endocrinology is advisable at this stage.

Ultrasound is recommended as second-line investigation

As above, an ultrasound scan is no longer a first-line investigation.

If requested, a transvaginal ultrasound is preferred as this has better specificity than transabdominal ultrasound for detecting polycystic ovarian morphology.

Polycystic ovarian morphology is confirmed on the scan if there is:

20 follicles per ovary; or
10 per section of an ovary; or
Ovarian volume >10ml

Ultrasound findings on their own are not sufficient to diagnose PMOS, as one in four women have polycystic ovarian morphology on their ultrasound scan without any clinical/ biochemical hyperandrogenism.

In adolescence, up to 70% of patients can show polycystic ovarian morphology on ultrasound, irrespective of presence of PCOS (PMOS), but as above this group often have irregular cycles anyway and therefore can only be considered ‘at risk’ and reassessed later once mature.

Lifestyle modification is key

It is important to provide a personalized, holistic management plan. Patients should be screened for metabolic risk factors – PCOS (PMOS) is associated with increased risk of type 2 diabetes, dyslipidemia, hypertension and obstructive sleep apnea. PCOS (PMOS) is also considered high risk for pregnancy, being associated with increased risk of GDM, pre-eclampsia, miscarriage and premature delivery, so it is important to counsel for this.

Recommended assessments include:

HbA1c
Lipid profile
Blood pressure
BMI
Sleep apnea screening tools (STOP-BANG/Epworth).

No single diet is specifically recommended for PCOS (PMOS). Any healthy diet that is sustainable, financially viable and the patient enjoys is what is advised.

Crucially it is worth mentioning that weight loss of even 5% of total body weight can have significant positive effects on fertility and metabolic outcomes.

Mental health screening is essential

PMOS is strongly associated with mental health disorders including anxiety, depression, eating disorders, psychosexual dysfunction and body image distress.

Menstrual symptoms: combined oral contraception remains the first-line treatment

Any standard COCP is acceptable if the patient has no contraindications. Pills with <30 mcg ethinyloestradiol are advised where possible (as there is no clinical advantage of a higher dose).

The levonorgestrel intrauterine device (LNG-IUD) or the progestogen-only pill are alternatives.

Dianette can be considered second-line, but it has higher oestrogen and therefore increased VTE risk.

Note patients with oligomenorrhoea (less than three periods in a year) who decline hormonal treatment will have high circulating unopposed oestrogen, which can lead to endometrial hyperplasia, so will they require prescription of cyclical progestogen.

Metformin for cardiometabolic regulation can be started in primary care

Metformin can be considered for:

BMI >25 (apply lower BMI thresholds in South Asian patients, in line with NICE obesity guidelines).

Typical dose:

Started at 500mg daily.
Titrated up gradually to a max dose of 2.5g in adults and 2g in adolescents.

Note this is off-licence use; also patients on metformin should now be routinely monitored patients if they have symptoms or are at risk of B12 deficiency.

Obesity – patients must be on contraception prior to bariatric surgery

Management may involve anti-obesity medication or bariatric surgery.

Note patients should already be on long-term contraception before undergoing bariatric surgery – their fertility may return very quickly after, and there are risks associated with pregnancy very soon after surgery with potentially worse neonatal outcomes.

Hirsutism options remain limited

Unfortunately few treatments are available on the NHS.

Cosmetic treatments (such as laser, phototherapy, electrolysis, waxing and shaving) can be accessed privately.

Other options include:

COCP (limited evidence).
Eflornithine (Vaniqa) is rarely used.

Acne treated as per PCDS guidelines

In summary this involves:

Topical treatments including retinoids +/- antibiotics.
COCP.

If the above are ineffective, off-license anti-androgen treatments that can be considered include:

Spironolactone 25-100mg OD.

When referral is required

Patients should be referred where:

Treatment fails in primary care.
Fertility treatment is required.
Testosterone >5 nmol/L (urgent endocrine referral to exclude tumour).

Key points

The international Monash guidelines on PCOS are the gold standard – however, NICE is due publish guidelines at the end of 2026.
The name PCOS has now officially changed to polyendocrine metabolic ovarian syndrome (PMOS) and the RCOG and NICE are adopting the new name.
Diagnosis is based on irregular cycles and hyperandrogenism (clinical or biochemical).
Ultrasound or AMH testing can be undertaken if only one of the above are present.
Metformin can be started in most patients with raised BMI above 25 to improve metabolic outcomes.
Risk factors should be screened for and treated accordingly.

Dr Mehreen Ali Khan is a GP with extended role in community gynaecology in Greater Manchester