Amenorrhoea

8


Amenorrhoea



Introduction


Amenorrhoea may be defined as the failure of menstruation to occur at the expected time.


It may be considered in two categories:


1. Primary amenorrhoea, when menstruation has never occurred.


2. Secondary amenorrhoea, when established menstruation ceases for 6 months or more.


Primary amenorrhoea


Failure to menstruate by the age of 16 is referred to as ‘primary amenorrhoea’. The likely cause of primary amenorrhoea depends on whether secondary sexual characteristics are present or not. If secondary sexual characteristics are absent, then the cause is most likely delayed puberty (see p. 45). If pubertal development is normal, then an anatomical cause should be suspected. The main ‘anatomical’ causes are:


icon01.gif congenital absence of the uterus; this is due to a failure of the Müllerian ducts to develop


icon01.gif imperforate hymen; the menstrual blood is retained within the vagina (a haematocolpos) causing cyclical lower abdominal pain each month at the time of menstruation (cryptomenorrhoea). Inspection of the vulva reveals a distended hymenal membrane through which dark blood may be seen and treatment by incision, usually under anaesthesia, is all that is required (Fig. 8.1).



Failure to menstruate may also be physiological delay, in other words, the development is normal but there is an inherent delay in the onset of menstruation. There is often a family history of the same delay in the mother. A progestogen challenge test is useful to identify constitutional menstrual delay. A progestogen (e.g. norethisterone) is given orally for 5 days, and withdrawal should lead to a vaginal bleed. If such a bleed occurs, it is reasonable to offer reassurance that spontaneous menstruation is likely to occur. An abdominal ultrasound may be reassuring to confirm that the uterus and ovaries are normal.


Low body weight and excessive exercise are also associated with primary amenorrhoea. The other causes listed in Table 8.1 are rare, although a few are outlined under the ‘secondary amenorrhoea’, discussion below (see also Chapters 5 and 6).



Secondary amenorrhoea


Secondary amenorrhoea means the cessation of established menstruation. It is defined as no menstruation for 6 months in the absence of pregnancy. A full list of causes is given in Table 8.2, but the commonest are weight loss, polycystic ovary syndrome (PCOS) and hyperprolactinaemia. The more common conditions are discussed below.



Causes


Physiological

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Jun 15, 2016 | Posted by in OBSTETRICS | Comments Off on Amenorrhoea

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