Endocrine

Many endocrine disorders can cause amenorrhoea. The most common causes are functional disorders of the hypothalamus and hyperprolactinaemia.

Hypothalamic disorders:

• hypogonadotrophic hypogonadism - e.g. Kallmann's syndrome
• psychogenic - associated with emotional stress, shift work especially, night / day shifts
• exercise
• excessive weight gain / weight loss
• eating disorders - anorexia nervosa, bulimia
• infections - e.g. tuberculosis, syphilis
• chronic diseases - e.g. diabetes, AIDS (1)
• tumours - e.g. craniopharyngioma
• post-oral contraceptive use - "post-pill amenorrhoea"

Pituitary lesions:

• tumours - with or without hyperprolactinaemia; includes prolactin secreting pituitary adenomas, non-functional pituitary adenomas with suprasellar extension impairing blood flow down the pituitary stalk; growth hormone secreting tumours - 30% secrete prolactin
• infarction necrosis - Sheehan's syndrome
• granulomatous infiltration - e.g. sarcoidosis

Ovarian lesions:

• ovarian dysgenesis - Turner's syndrome / mosaic
• polycystic ovarian syndrome
• resistant ovary syndrome
• premature ovarian failure
• androgen secreting ovarian tumours
• surgery - oophorectomy; ovarian suppression by pelvic irradiation

Other endocrine lesions:

• thyroid - primary hypothyroidism; hyperthyroidism
• pancreas - poorly controlled diabetes
• adrenal - Cushing's syndrome; advanced Addison's disease

Notes:

• head injury and gonadotropin deficiency (2)
  • marked changes of the hypothalamo-pituitary axis have been documented in the acute phase of traumatic brain injury (TBI)
    • following TBI as many as 80% of patients showing evidence of gonadotropin deficiency, 18% of growth hormone deficiency, 16% of corticotrophin deficiency and 40% of patients demonstrating vasopressin abnormalities leading to diabetes insipidus or the syndrome of inappropriate anti-diuresis
    • longitudinal prospective studies have shown that some of the early abnormalities are transient, whereas new endocrine dysfunctions become apparent in the post-acute phase. There remains a high frequency of hypothalamic-pituitary hormone deficiencies among long-term survivors of TBI, with approximately 25% patients showing one or more pituitary hormone deficiencies

Reference:

• (1) Practice Committee of the American Society for Reproductive Medicine (2008) Current evaluation of amenorrhea. Fertil Steril 90(5 Suppl), S219-S225.
• (2) Behan LA et al. Neuroendocrine disorders after traumatic brain injury. J Neurol Neurosurg Psychiatry. 2008 Jul;79(7):753-9