Ectopic and Heterotopic Pregnancies

Ectopic pregnancy (EP), where an embryo implants outside of the normal uterine cavity, occurs in 1%–2% of all pregnancies. It is termed heterotopic if there is also a concurrent intrauterine pregnancy. 95%–98% of EPs occur within the Fallopian tube where placental invasion of maternal vasculature can cause life-threatening hemorrhage. Factors that alter or impede embryo transport can increase the risk of developing EP. Detection is largely by transvaginal ultrasound and, where there is diagnostic uncertainty, serial serum β-hCG monitoring. EP can be managed surgically, medically or expectantly. Further improvements in diagnostics and medical management are required to improve patient outcomes.