Pedagogy: This lesson uses definition-mapping and staging-system application to build foundational terminology — the scaffold upon which all subsequent clinical reasoning rests.

All Levels 15 min

Learning Objectives

Define menopause, perimenopause, postmenopause, premature ovarian insufficiency (POI), and early menopause using internationally accepted terminology.
Describe the epidemiology of menopause including mean age, global variation, and prevalence of vasomotor symptoms.
Apply the STRAW+10 staging system to classify a patient's reproductive stage.
Explain the societal and economic impact of menopause, including workforce participation data.
Identify the treatment uptake gap and its implications for primary care practice.

Key Facts

Terminology and Definitions

Menopause is a biological stage marked by the permanent cessation of menstruation resulting from the loss of ovarian follicular activity. A woman is defined as postmenopausal from 12 months after her final menstrual period (FMP). The term is a retrospective diagnosis, confirmed only after 12 consecutive months of amenorrhoea in the absence of other pathological or physiological causes (1,2).

Term	Definition
Perimenopause	The interval encompassing the menopausal transition and the 12 months following the FMP (STRAW stages −2 to +1a). Characterised by menstrual irregularity, fluctuating hormones, and onset of symptoms.
Menopause	The FMP, determined retrospectively after 12 months of amenorrhoea. STRAW stage 0. Mean age in the UK: 51 years.
Postmenopause	The period beginning 12 months after the FMP and lasting until the end of life. STRAW stages +1 to +2.
Premature Ovarian Insufficiency (POI)	Loss of ovarian activity before age 40. Affects 3.5–3.7% of the global female population. Requires FSH >25 IU/L on two samples 4–6 weeks apart.
Early Menopause	Menopause occurring between ages 40 and 44. Affects approximately 5% of women. Carries intermediate long-term health risk.

Epidemiology

The mean age of natural menopause is 51.4 years (SD 3.3), with 90% of women experiencing menopause between ages 45 and 56. Women typically spend approximately 40% of their lifespan in the postmenopausal state. Around 80% experience vasomotor symptoms (VMS), with a median total VMS duration of 7.4 years (1).

Despite high symptom prevalence, fewer than 25% of women with bothersome menopausal symptoms receive HRT. Socioeconomic status, geography, and physician specialty all influence prescribing rates. Women managed by gynaecologists are significantly more likely to receive MHT than those managed by family physicians (2). This treatment uptake gap underscores the critical role of primary care education.

The STRAW+10 Staging System

The Stages of Reproductive Ageing Workshop (STRAW+10) criteria provide the internationally accepted framework for staging reproductive ageing. Menopause (FMP) is designated as point zero (0) (1,2).

Stage	Phase	Menstrual Criteria	Endocrine Markers
−5 to −3	Reproductive	Variable to regular cycles	Normal FSH; normal AMH
−2	Early Menopausal Transition	Cycle length varies ≥7 days	FSH rising; AMH low
−1	Late Menopausal Transition	Amenorrhoea ≥60 days	FSH >25 IU/L; AMH very low
0	Menopause (FMP)	Final menstrual period	FSH elevated; oestradiol low
+1a/b	Early Postmenopause	Amenorrhoea	FSH stabilising high
+2	Late Postmenopause	Amenorrhoea	FSH high; somatic changes

The IMS 2025 recommendations note that onset of moderately-to-severely bothersome VMS in women over 40, regardless of menstrual cycle changes, should prompt clinical evaluation of reproductive staging (2).

Clinical Pearl Menopause is a clinical diagnosis in women aged over 45 presenting with typical symptoms. FSH testing is NOT routinely required in this age group (NICE NG23, 2024; ESE 2025). Reserve biochemical testing for women under 40 (suspected POI) or ages 40–45 with diagnostic uncertainty.

Clinical Pearl The STRAW+10 system uses menstrual cycle characteristics as primary staging criteria. However, VMS and changed menstrual flow may signal the onset of the menopausal transition BEFORE cycle irregularity meets formal STRAW+10 thresholds (IMS 2025).

Case-Based Examples

Case 1: 49-year-old with hot flushes — does she need a blood test?

Presentation: A 49-year-old woman attends your GP surgery reporting hot flushes 8–10 times daily, night sweats disrupting sleep, and increasingly irregular periods over the past 18 months. Her last period was 3 months ago. No significant PMH. BMI 26. She asks whether she needs a blood test to confirm menopause.

Question: What is the appropriate diagnostic approach and how would you stage this patient using STRAW+10?

Model Answer: This patient is aged over 45 with classic menopausal symptoms and menstrual irregularity. Per NICE NG23 (2024) and the ESE guideline (2025), menopause/perimenopause is a clinical diagnosis in this age group — FSH testing is NOT required. Her amenorrhoea of ≥60 days with preceding cycle irregularity places her in the late menopausal transition (stage −1). She should be counselled, offered treatment options for VMS, and have a structured assessment for cardiovascular and bone health risk factors.

Case 2: 42-year-old with amenorrhoea and fertility concerns

Presentation: A 42-year-old woman presents with 6 months of amenorrhoea, hot flushes, vaginal dryness, and low mood. Her mother experienced menopause at age 39. BMI 23, no medications, no children (planning to conceive). She stopped the combined OCP 8 months ago.

Question: How would you approach the diagnosis? What additional considerations arise given her age and fertility concerns?

Model Answer: At 42, this patient falls into the early menopause range (40–44). Step 1: Check FSH (elevated >25 IU/L would be suggestive); repeat at 4–6 weeks. Step 2: Exclude pregnancy, thyroid dysfunction, and hyperprolactinaemia. Step 3: Given family history (mother menopause age 39), consider FMR1 premutation screening and karyotype. Step 4: Urgent referral to reproductive medicine — intermittent ovulation occurs in up to 25% of women with POI/early menopause. Step 5: Recommend HRT to prevent long-term cardiometabolic, skeletal, and neurological consequences, at least until age 51. NICE NG23: HRT is not a contraceptive; additional contraception needed if pregnancy is not desired.

Self-Assessment Questions

PLAB/MLA Diagnosis of menopause in a 52-year-old

A 52-year-old woman presents with hot flushes and 14 months of amenorrhoea. Her GP requests FSH and oestradiol. Which statement is MOST accurate?

A. An FSH >30 IU/L is required to confirm menopause
B. Oestradiol must be below reference range
C. Biochemical testing is not required for diagnosis
D. AMH is the most reliable marker
E. FSH should be measured on days 2–5

Answer: C. In women over 45 with typical symptoms and 12 months amenorrhoea, menopause is a clinical diagnosis. NICE NG23 (2024) and the ESE guideline (2025) state biochemical testing is not necessary. AMH is not recommended for diagnosing menopause; day 2–5 timing only applies when cycles are present.

MRCGP Communicating STRAW+10 staging to a 44-year-old

A 44-year-old woman presents with 4 months of menstrual irregularity and occasional hot flushes. Her mother had menopause at age 43. She asks whether she might be entering menopause.

Discuss the diagnostic approach and how you would communicate STRAW+10 staging to support shared decision-making.

Model Answer: Aged 40–45 with menstrual irregularity and VMS — clinical diagnosis alone may be insufficient. NICE NG23 suggests FSH testing may be considered at ages 40–45 with diagnostic uncertainty. A single elevated FSH (>25 IU/L) supports menopausal transition diagnosis; values fluctuate so may need repeating. Using STRAW+10, her variable cycle length suggests early menopausal transition (stage −2). Explain perimenopause is gradual, symptoms fluctuate, treatment options exist. Family history (mother age 43) is a recognised risk factor. Discuss HRT option if symptoms are bothersome, contraception counselling (fertility persists), and structured multi-domain assessment including cardiovascular risk.

Professor Critical appraisal of the STRAW+10 system

The STRAW+10 staging system relies primarily on menstrual cycle characteristics. The IMS 2025 notes bothersome VMS may precede formal STRAW+10 criteria.

Critically appraise the strengths and limitations of STRAW+10. How might precision biomarkers (AMH trajectories, genomic predictors) improve staging accuracy?

Model Answer: Strengths: standardised, internationally accepted framework; retrospective validation across multiple ethnic groups (SWAN, Melbourne study); integration of menstrual and endocrine criteria. Limitations: reliance on regular cycles as baseline (problematic with PCOS, hormonal contraception, post-hysterectomy); inability to predict FMP timing prospectively; symptom onset may precede formal staging (IMS 2025). Precision biomarkers: AMH trajectory modelling (Freeman model) shows promise for FMP prediction within 1–2 years. GWAS-identified variants (BRSK1, MCM8, STARD3) may contribute to polygenic risk scores. Barriers: AMH assay variability; limited prospective validation of genomic predictors in diverse populations; health-economic evaluation needed before adoption.

Take-Away Messages

Menopause is a clinical diagnosis in women aged ≥45 with typical symptoms; FSH testing is NOT routinely required.
STRAW+10: menopause = stage 0; perimenopause = stages −2 to +1a.
Mean age of natural menopause: 51 years (UK); 80% experience VMS; median VMS duration 7.4 years.
POI (<40 years) and early menopause (40–44) carry significant long-term health risks requiring proactive management.
Fewer than 25% of symptomatic women receive HRT — primary care must close this treatment gap.

References

Crandall CJ, Mehta JM, Manson JE. Management of menopausal symptoms: a review. JAMA. 2023;329(5):405–420. DOI
Lumsden MA, Rees M, Aarts JWM, et al. ESE Clinical Practice Guideline: evaluation and management of menopause. Eur J Endocrinol. 2025;193(4):G49–G79. DOI
NICE. Menopause: identification and management [NG23]. Updated November 2024. Link

Lesson 1.1: Definitions, Epidemiology and the STRAW+10 Staging System