**2.1 Introduction/definition/incidence**

AP represents a variant of ectopic gestation in which the conceptus is sited in the abdominal cavity, external to the uterus, fallopian tubes and broad ligament (1, 2). Devoid of endometrial support, the placenta may attach to the peritoneum, bowel, uterine serosa and omentum. AP is the rarest form of ectopic pregnancy, with an incidence of 1% of all ectopic gestations (3).

AP is defined as advanced once fetal viability is reached. At this stage AP carries significantly high mortality rates for both mother (0-20%) and fetus/newborn (40-95%) (2, 4). The latter is partly due to a 20-40% rate of congenital fetal malformations (4).
