11th April 2024

Aetiology

Primary hypogonadism

Primary hypogonadism (hypergonadotropic hypogonadism) in a woman is a pathology of the ovaries resulting in failure of normal ovulation and production of adequate oestrogen. It is characterised by disruption to the menstrual cycle (amenorrhoea/oligomenorrhoea) as well as biochemical features such as raised FSH and LH with low oestradiol. Congenital causes of gonadal dysgenesis include Turner (45X) and Fragile X syndrome. Streak ovaries are seen when there is abnormality or absence of the X chromosome and are associated with Turner syndrome. Acquired primary hypogonadism can be due to iatrogenic causes such as chemotherapeutic agents, therapeutic oophorectomy, as well as infections and autoimmune diseases, including haemochromatosis. 

Secondary hypogonadism

Secondary hypogonadism is caused by pathology of the HPA axis (hypothalamus and/or pituitary), resulting in a downstream reduction in the production of gonadotrophins. Congenital causes include Kallmann syndrome, which is the most common genetic cause and is seen more often in men (3.6:1). Space occupying lesions, infiltrative diseases such as sarcoidosis and amyloidosis, meningitis, pituitary apoplexy and Sheehan’s syndrome are examples of secondary causes.