Case 24.5 – Primary Amenorrhoea [SDL]
Category: Medicine | Discipline: Obstetrics & Gynaecology | Setting: Self-Directed Learning
Learning Objectives
This is a self-directed learning (SDL) case. Use the key learning points below to guide your independent study of primary amenorrhoea.
Key Topics to Cover
- Definition: Primary amenorrhoea = no menarche by age 15 (with normal secondary sexual characteristics) OR age 13 (with absent secondary sexual characteristics)
- Causes - Hypogonadotropic hypogonadism (low FSH/LH):
- Constitutional delay (most common) - family history, delayed puberty, late menarche
- Kallmann syndrome - GnRH deficiency + anosmia, low FSH/LH
- Hypothalamic - stress, weight loss, excessive exercise, chronic illness
- Hyperprolactinaemia, pituitary tumours
- Causes - Hypergonadotropic hypogonadism (high FSH):
- Turner syndrome (45,XO) - short stature, webbed neck, wide-carrying angle, coarctation of aorta, streak ovaries
- Premature ovarian insufficiency
- Gonadal dysgenesis
- Causes - Structural abnormalities (normal FSH/LH):
- Imperforate hymen - cyclical pelvic pain, bulging hymen, haematocolpos (blood-filled vagina)
- MRKH syndrome (Mayer-Rokitansky-Küster-Hauser) - absent uterus/upper vagina, normal ovaries, normal female phenotype
- Transverse vaginal septum
- Androgen insensitivity syndrome (AIS) - 46,XY with female phenotype, testes (intra-abdominal), absent uterus, blind-ending vagina
- Investigations: FSH/LH, oestradiol, prolactin, TSH, karyotype, pelvic USS, MRI pituitary (if indicated)
- Management: Depends on cause - hormone replacement (Turner syndrome), surgical correction (imperforate hymen), fertility counselling
Recommended Resources
Refer to your lecture notes, textbooks (e.g., Oxford Handbook of Obstetrics & Gynaecology), and online resources (NICE guidelines, RCOG Green-top guidelines) to explore these topics in detail.