History

Introduction

An ectopic pregnancy (EP) occurs when a fertilized oocyte im­plants outside the main cavity of the uterus. This places the woman at risk of physical harm, psychological morbidity, and death (1, 2).

EP occurs in 1 in 80 pregnancies (1). The vast majority (around 98%) of EPs result from implantation of the fertilized oocyte in the lumen of the fallopian tube. Other sites of implantation in­clude the ovary, abdominal organs, cervical canal, and interstitial portion of the Fallopian tube. The former two fulfil the definition of implantation outside the normal uterine cavity, as do caesarean section scar EPs. These refer to implantation within a notch of exposed myometrium that communicates with the endometrial cavity. These notches are found after caesarean section and are at a level corresponding to the lower uterine segment in the non- gravid uterus. The aetiology of EP is uncertain, although tubal implantation is probably due to retention of the embryo in the fallopian tube due to impaired embryo-tubal transport and alter­ations in the tubal microenvironment (3).

EP is the leading cause of maternal death in the first trimester in both resource-rich and resource-poor settings. In the short term, EP causes morbidity from intraperitoneal bleeding and further morbidity arises from the measures necessary to address this, such as emergency surgery, blood transfusion, and postoperative pain. Longer term, women who have suffered from an EP are at risk of a repeat EP, subfertility, and chronic pelvic pain. In the majority of women, an EP is the loss of a wanted pregnancy, and this can also result in psychological morbidity.