Abdominal pregnancy: a study of twenty-one consecutive cases.

Early abdominal pregnancy is self-limited by hemorrhage from trophoblastic invasion, with complete abortion of the gestational sac that leaves a discrete crater which is sometimes difficult to identify. Advanced abdominal pregnancy survives the hemorrhage of trophoblastic invasion and partial tubal abortion and implants secondarily in the first trimester on any adjacent structure. It may progress to term if not diagnosed or interrupted by abruptio placentae and have spurious labor and fetal death. A case of cornual abortion with secondary implantation on the uterus is discussed.