Endometriosis is one of the most frequently encountered gynaecological diseases. Its aetiology, physiology and treatment remain controversial. This chapter covers the diagnosis, aetiology, assessment and treatment options for this disorder and discusses its role in infertility and prognosis after treatment.

Incidence

The true incidence of endometriosis remains unknown, despite a number of studies that have tried to estimate it. One study stated that 10–15% of all premenopausal women had this disorder (Hasson, 1976); another found it in 10–15% of women undergoing diagnostic laparoscopy for pain, infertility and dysmenorrhoea. The latter study also looked at women undergoing laparoscopic sterilization and found that only 2–5% had endometriosis (Strathy, Molgaard and Coulman, 1982). It also looked at women with infertility alone and found that 30–40% of women who underwent laparoscopy for infertility had endometriosis. The conclusion was that endometriosis had to be related in some way to infertility as either an association or a cause or effect.

Pathogenesis

Before pathogenesis can be discussed, it is important to have a uniformly accepted definition of the disease. The gold standard in diagnosis is the presence of histologically documented menstrual glands and stroma outside the uterus. It also helps if there is evidence of menstrual cyclicity with haemosiderin-laden macrophages.

Coelomic metaplasia

This was the first widely considered theory of the pathogenesis of endometriosis. According to this proposal, in response to certain unspecified stimuli, cells may undergo a metaplastic process which changes their character and physiological function.