Introduction

Miscarriage is the most common complication of pregnancy. It rarely causes serious health problems, but it can adversely affect women's social and psychological wellbeing. Ectopic pregnancy is less common than miscarriage, but it remains the leading cause of first-trimester maternal mortality and is associated with significant physical and psychosocial morbidity.

According to the Seventh Report on Confidential Enquiries into Maternal Deaths in the United Kingdom, there are around 1000 000 pregnancies per year in the UK, with approximately 700 000 deliveries occurring each year. It is estimated that the number of miscarriages per year is at least 200 000 and the number of ectopic pregnancies at least 10 000. The maternal mortality rate in relation to early pregnancy complications in the UK in the 3 years between 2003 and 2005 was 0.47/100 000 maternities for ectopic pregnancy (a total of ten deaths) and 0.05/100 000 maternities for miscarriage (one recorded death). Thus, despite a relatively low mortality rate, the overall impact of these disorders on women's health is significant.

Miscarriage is conventionally quoted to affect one in five pregnancies and ectopic pregnancy to occur in 1/100 gestations; however, establishing the true rate of these early pregnancy complications is challenging owing to the lack of accurate data. Hospital statistics provide information regarding the rate of miscarriage and ectopic pregnancy resulting in hospital admissions. However, the majority of women diagnosed with miscarriage are nowadays managed without admission to hospital.