For the past 50 years, the mainstay of treatment for the management of miscarriage has been surgical management, or the evacuation of retained products of conception. Until recently, up to 88% of women diagnosed with a miscarriage would be offered an evacuation of retained products of conception under general anaesthesia. The rationale for surgical management was based on the assumption that the presence of a non-viable pregnancy within the uterus would increase the risk of infection and haemorrhage. In the past, these complications were more likely to develop from infected retained products of conception following poorly performed illegal abortions but, with the legalisation of abortion in developed countries, the introduction of antibiotics and a general improvement in women's health, these risks have decreased substantially. Over the past decade, there has been less emphasis on urgent surgical management and more on individualised treatment and patient choice between expectant, medical and semi-elective surgical treatment.
Expectant management is chosen by women because of a desire for a natural approach to management. It is becoming an increasingly popular option; in one observational study, 70% of women opted to wait for the pregnancy to resolve spontaneously. The first randomised controlled trial of expectant management compared with surgical management of miscarriage, carried out by Nielsen and Hahlin, showed a 79% success rate for cases of incomplete or inevitable miscarriage when managed expectantly for 3 days, with no increased risk of pelvic infection or excessive bleeding.