Premature ovulation failure

 

Premature Ovarian Failure (POF) or a premature menopause occurs when a woman’s periods stop before the age of 40. There is often some warning, just as there is at the time of the natural menopause (around the age of 50 for most women) with periods becoming irregular and more widely spaced. Sometimes, however, periods cease suddenly. The ovaries stop producing the hormone estrogen and so symptoms of estrogen deficiency can occur, including hot flushes, mood changes and vaginal dryness. The ovaries also stop producing eggs and so conception is extremely unlikely.

There is not always an explanation for a premature menopause. It sometimes runs in families, with women having their menopause at a similar age to their mother. Some women have abnormalities of the genes that control ovarian function, others make ‘autoantibodies’ which prevent the ovaries from working and a few women can be affected by viral infections of their ovaries. The ovaries can rarely start working again on their own, although this is the exception rather than the rule, and studies that have examined women with POF report only a minority of woman resuming spontaneous ovulations.

Some women can have quite a long period during which the ovaries are slowing down rather than stopping and ovulation may occur from time to time. This is a condition called the ‘resistant ovary syndrome’, during which time the ovaries are resistant to the two hormones that come from the pituitary and which stimulate the ovaries to release eggs and estrogen. These pituitary hormones are FSH (follicle stimulating hormone) and LH (luteinizing hormone). The levels of FSH and LH in the blood at the time of the menopause are very high as they are trying to encourage the ovaries to work. POF is therefore diagnosed by at least two blood tests which show elevated blood levels of FSH and LH. It is usual to check other hormones at the same time (prolactin, thyroxine, and, sometimes oestradiol).

The ovaries will not respond to the body’s natural FSH and LH and this is why they will not respond to FSH/LH injections, which are used to stimulate ovulation successfully in other women who have ovaries with eggs but a break down in the natural mechanisms that stimulate the ovaries. In fact there are, unfortunately, no treatments that will make resistant or menopausal ovaries work again. Woman with POF should be given hormone replacement therapy (HRT) which will provide the right amounts of estrogen (together with progesterone, another ovarian hormone) and an artificial menstrual cycle. Estrogen is important to both prevent the above mentioned symptoms and to prevent the long term effects of estrogen deficiency (thinning of bones) and cardiovascular disease (heart attacks and strokes). It is recommended that HRT is taken at least until the age of 50. HRT is preferable to the contraceptive pill, which will also provide an artificial menstrual cycle but will not allow ovulation to occur and if pregnancy is desired it can occur whilst taking HRT, even though the chances of ovulation are extremely unlikely. Nowadays it is possible to have ‘in vitro fertilization’ (IVF) using donated eggs, usually from an anonymous donor, which have been fertilized by the sperm of the recipients partner. Egg donation provides an approximately 25-30% chance of a pregnancy with each attempt.

By Adam H. Balen