7 - Amenorrhoea

Summary

Amenorrhoea is the absence of menstruation, either temporary or permanent. It may occur as a normal physiological condition, before puberty and during pregnancy, lactation or the menopause, or it may be a feature of a systemic or gynaecological disorder.

Primary amenorrhoea

The failure to menstruate by the age of 16 years in the presence of normal secondary sexual development or by 14 years in the absence of secondary sexual characteristics warrants investigation. This distinction helps to differentiate reproductive tract anomalies from gonadal quiescence and gonadal failure (Chapter 4). Primary amenorrhoea may be a result of congenital abnormalities in the development of ovaries, genital tract or external genitalia or of a disturbance of the normal endocrinological events of puberty. Most of the causes of secondary amenorrhoea can also cause primary amenorrhoea if they occur before the menarche. Delayed puberty is often constitutional but it is important to exclude primary ovarian failure and hypothalamic or pituitary dysfunction. Overall it is estimated that endocrine disorders account for approximately 40% of the causes of primary amenorrhoea, the remaining 60% having developmental abnormalities.

For causes of primary amenorrhoea other than those described under the classification of secondary amenorrhoea, see Chapter 1 for congenital developmental anomalies and Chapter 4 for endocrinological disturbances of puberty.

Secondary amenorrhoea

Cessation of menstruation for six consecutive months in a woman who has previously had regular periods is the usual criterion for investigation.