Amenorrhoea in Adolescents

Assessment and management — a clinical summary

Amenorrhoea means that menstrual periods are absent: either they have never started, or they have stopped. Because the menstrual cycle is one of the clearest signs of a young woman’s overall health, missing periods in a teenager always deserve careful assessment.

1. Two types of amenorrhoea

•        Primary amenorrhoea: Periods have never started: no period by age 15 in a girl who has otherwise gone through puberty, by age 13 if there are no signs of puberty at all, or within 3 years of breast development beginning. (Prevalence (US data): <0.1%)

•        Secondary amenorrhoea: Periods that were previously regular have stopped for 3 months, or irregular periods have stopped for 6 months. (Prevalence (US data): ≈4%)

2. What causes it?

Most common causes of primary amenorrhoea

•        Premature ovarian insufficiency (POI): 48.5%

•        Uterus and vagina absent from birth (e.g. MRKH syndrome): 16.2%

•        GnRH deficiency (e.g. Kallmann syndrome): 8.3%

•        Constitutional delay of puberty: 6.0%

Where in the body the problem lies

•        Brain (hypothalamus or pituitary) — weak hormone signals — hypogonadotropic hypogonadism

•        Ovaries — the ovaries do not respond — hypergonadotropic hypogonadism, present from birth or acquired

•        Uterus and genital tract (Müllerian tract) — hormones are normal, but the flow is blocked or structures are absent — can cause primary or secondary amenorrhoea

•        Other hormone (endocrine) disorders

•        Constitutional delay — puberty is simply arriving later than usual

The FIGO framework for ovulatory disorders

•        First level — HyPO-P: Hypothalamus, Pituitary, Ovary, and PCOS

•        Second level — GAIN-FIT-PIE: Genetic, Autoimmune, Iatrogenic, Neoplasm · Functional, Infectious/Inflammatory, Trauma/Vascular · Physiological, Idiopathic, Endocrine

3. Clinical assessment

History

•        Cyclical pelvic pain: hormones are working normally, but menstrual flow is blocked

•        Weight change or excessive exercise: functional hypothalamic amenorrhoea

•        Headaches or visual field problems: a possible brain (pituitary) tumour

•        Loss of the sense of smell: Kallmann syndrome (GnRH deficiency with a smell defect)

•        Features of thyroid disease or Cushing’s syndrome: an endocrine cause

•        Psychosocial wellbeing: assess using the HEADSS framework

Examination

•        Height and weight (auxology)

•        Breast development: shows the ovaries are producing oestrogen — graded with Tanner staging

•        Signs of excess male hormones (androgens): moderate–severe acne, excess hair (Ferriman–Gallwey score)

•        Stage of pubertal development

•        General physical examination

•        Neurological examination

4. Investigations

1. Pregnancy test

2. Blood tests: FSH, LH, prolactin, thyroid function, testosterone

3. Karyotype (chromosome test) if FSH is high

4. Pelvic ultrasound

Diagnostic caution: Do not conclude that the uterus is absent from an ultrasound done before puberty or before oestrogen treatment — an underdeveloped uterus can be very hard to see.

5. Management by cause

•        Anatomical problems: Surgery to relieve any blockage and keep the genital tract open; careful planning with MRI and a multidisciplinary team (MDT) meeting.

•        Gonadal dysgenesis: A karyotype is essential — Turner syndrome is the most common cause. Gonadectomy may be needed; puberty is induced with hormones.

•        Hypogonadotropic hypogonadism: Consider constitutional delay first, then treat the underlying cause: education, nutritional advice, combined hormone replacement therapy (HRT).

•        Other endocrine causes (e.g. prolactinoma): Bromocriptine or cabergoline, or surgical removal.

•        Functional hypothalamic amenorrhoea: Often linked to eating disorders. Needs a careful, thorough assessment and team care with a dietitian and psychologist; HRT or the combined pill (COCP).

•        Premature ovarian insufficiency: Counselling and psychological support; HRT with oestrogen plus progestogen; contraception advice.

•        PCOS / PMOS: Lifestyle changes, weight management and psychological support; a progestogen-induced bleed every 3–4 months to protect the womb lining; the combined pill (check eligibility with UKMEC/WHO-MEC); metformin as an add-on.

6. Principles of care

•        Fertility: Discuss the effects on fertility and the options for fertility preservation early, in a way suited to the young person’s age.

•        Patient-centred care: Care suited to her stage of development, respecting autonomy, beneficence, non-maleficence and justice.

•        Consent and confidentiality: Assess decision-making capacity and consent, keep confidentiality, and involve parents or carers appropriately.

Source: summarised in our own words from:

Lim LM, Latthe P. Amenorrhoea in Adolescents: A Guide to Management. The Obstetrician & Gynaecologist 2026. https://doi.org/10.1111/tog.70055

For information only — this does not replace a medical consultation.

Dr Najeeb Layyous