Abnormal pregnancy, occurring in about 2% of all pregnancies, in which the fertilised egg (conceptus, embryo) implants outside the uterus, most often (90%) in the fallopian tube (tubal pregnancy) but occasionally in the ovary (ovarian pregnancy) or abdominal cavity (abdominal pregnancy).
As the embryo develops, the tube ruptures or other complications arise, usually causing haemorrhage and requiring immediate surgery.