Primary versus secondary amenorrhoea

The causes of primary and secondary amenorrhoea overlap but the distinction is informative. Secondary amenorrhoea indicates a patent lower genital tract, an endometrium which has responded to ovarian hormones, and ovaries which have responded to gonadotrophins. Exceptions include surgery to the endometrium or cervix which rarely cause intrauterine adhesions or cervical stenosis respectively.

Congenital disorders usually present as primary amenorrhoea, for example:

• congenital malformations of the genital tract
• testicular feminisation
• gonadal dysgenesis
• congenital adrenal hyperplasia
• hypogonadotrophic hypogonadism

However, any cause of secondary amenorrhoea may present as primary amenorrhoea if it occurs before the age of 16 years.