Ectopic pregnancy characterized by the implantation of the embryo in the peritoneal cavity or abdominal organs.

An abdominal pregnancy is a rare type of ectopic pregnancy where the embryo or fetus is growing and developing outside the uterus, in the abdomen, and not in a fallopian tube (usual location), an ovary, or the broad ligament. Because tubal, ovarian and broad ligament pregnancies are as difficult to diagnose and treat as abdominal pregnancies, their exclusion from the most common definition of abdominal pregnancy has been debated. Others—in the minority—are of the view that abdominal pregnancy should be defined by a placenta implanted into the peritoneum..