The term ectopic, literally means "out of place". An ectopic pregnancy is one that does not occur in the womb, in the usual way. They sometimes occur in the abdomen, but are more frequently found in the Fallopian tubes, hence the name "tubal pregnancy".

In a normal reproductive cycle, an ovum ripens each month, and is released by the woman's ovary. That ovum is swept into the end of the Fallopian tube, where it makes its way down towards the womb, where it is generally fertilized by the man's sperm. The pregnancy can develop in the wrong place, if the egg is actually released into the abdomen and fertilized there, or if it becomes stuck in its progress down the Fallopian tube, and the fertilized egg anchors itself within the tube.

Symptoms of an ectopic pregnancy can include, but are not limited to: pain in the lower abdomen when there is a chance of pregnancy, shoulder pain from diaphragm irritation that is caused by internal bleeding, painful bowel movements, abnormal bleeding, low blood pressure and fainting.

An ectopic pregnancy can be caused by abnormalities within the Fallopian tubes that have created narrow passages. Women most at risk are those who have a past history of abdominal surgeries, pelvic infections, and those using the coil contraceptive or progesterone only birth control pill.