Premature ovarian insufficiency (POI) is a condition in which the ovaries stop functioning normally in women who are younger than 40 years leaving them in a hypo-oestrogenic state with elevated gonadotrophins and oligomenorrhoea/amenorrhoea. This leads to short term complications of menopausal symptoms and long-term effects on bone and cardiovascular health, cognition and there is also the impact of reduced fertility associated with this condition as well as problems with sexual function. It is managed by sex steroid replacement either with HRT or combined contraception until the age of natural menopause (50/51) and this can provide a beneficial role with both symptom control and minimising the long-term adverse effects associated with this condition.

Premature menopause should be defined as menopause that occurs at an age more than two standard deviations below the mean estimated for the reference population. In the absence of reliable estimates of age of natural menopause in developing countries, the age of 40 years is now universally agreed as the cut-off point for a menopause to be premature. It is estimated that 0.1% of women will become menopausal before the age of 40 and 0.01% below the age of 30. It may take months or years to progress from stages of ovarian insufficiency to true menopause.

Women who undergo a menopause between 40 and 45 years are deemed to have an “early menopause”. The extent of investigation and assessment in this group will depend on a variety of factors. However, the limited data available for this group suggest that they also have an increased morbidity if not adequately treated with hormone therapy. As such, women who have an early menopause should be managed in a similar way to those with POI, with the recommendation that they should take HRT at least until the natural age of menopause.