Menstrual - Amenorrhoea


Amenorrhoea may be divided into:

  • primary: defined as the failure to establish menstruation by 15 years of age in girls with normal secondary sexual characteristics (such as breast development), or by 13 years of age in girls with no secondary sexual characteristics

  • secondary: cessation of menstruation for 3-6 months in women with previously normal and regular menses, or 6-12 months in women with previous oligomenorrhoea



Causes


Primary amenorrhoea

Secondary amenorrhoea (after excluding pregnancy)

  • gonadal dysgenesis (e.g. Turner's syndrome) - the most common causes

  • testicular feminisation

  • congenital malformations of the genital tract

  • functional hypothalamic amenorrhoea (e.g. secondary to anorexia)

  • congenital adrenal hyperplasia

  • imperforate hymen

  • hypothalamic amenorrhoea (e.g. secondary stress, excessive exercise)

  • polycystic ovarian syndrome (PCOS)

  • hyperprolactinaemia

  • premature ovarian failure

  • thyrotoxicosis*

  • Sheehan's syndrome

  • Asherman's syndrome (intrauterine adhesions)


Investigation and management


Initial investigations

  • exclude pregnancy with urinary or serum bHCG

  • full blood count, urea & electrolytes, coeliac screen, thyroid function tests

  • gonadotrophins

    • low levels indicate a hypothalamic cause where as raised levels suggest an ovarian problem (e.g. Premature ovarian failure)

    • raised if gonadal dysgenesis (e.g. Turner's syndrome)

  • prolactin

  • androgen levels

    • raised levels may be seen in PCOS

  • oestradiol


Management

  • primary amenorrhoea:

    • investigate and treat any underlying cause

    • with primary ovarian insufficiency due to gonadal dysgenesis (e.g. Turner's syndrome) are likely to benefit from hormone replacement therapy (e.g. to prevent osteoporosis etC)

  • secondary amenorrhoea

    • exclude pregnancy, lactation, and menopause (in women 40 years of age or older)

    • treat the underlying cause


*hypothyroidism may also cause amenorrhoea