This occurs when a fertilized egg implants outside of the uterine cavity. The vast majority of ectopic pregnancies are in the fallopian tube, but they can occur on an ovary, in the cervix, or in the abdominal cavity at the site of a previous cesarean.
Any woman can have an ectopic pregnancy. However, the risk of an etopic pregnancy is increased if you have had a pelvic infection; became pregnant with a progesterone-releasing IUD in place, while taking the mini-pill, or as a result of fertility treatment; have endometriosis; have had abdominal surgery such as a cesarean section; or a previous ectopic pregnancy.
Most women who have an ectopic pregnancy will notice pain and light bleeding at 6-8 weeks (2-4 weeks after a missed period). The pain is usually felt on one side of the lower abdomen and it may be severe and persistent. If an ectopic pregnancy is not recognized early and an embryo growing in the fallopian tube ruptures the tube, you may feel sudden severe pain that spreads across the abdomen. Internal bleeding from a ruptured tube can also irritate the diaphragm, causing shoulder pain. If you have severe lower abdominal pain, call your doctor and go immediately to the emergency room.
What might be done
If the tube has ruptured, then you will be taken straight to surgery. Usually, an ectopic pregnancy is suspected before this stage. In this case you will have an ultrasound scan, usually performed through the vagina, which often diagnoses the problem; there will be no baby in the uterus; blood may be seen in the abdomen; and sometimes the ectopic pregnancy itself can be seen. You may also have blood tests taken over a period of 48 hours to monitor the levels of hCG (the pregnancy hormone); if levels of hCG plateau or rise slightly, this indicates an ectopic pregnancy. If an ectopic pregnancy has not been confirmed by these investigations, you will probably be taken to surgery for a laparoscopy, a procedure where a telescope is inserted through a small incision in the abdomen, allowing the surgeon to see exactly what is happening. If there is an ectopic, and if the tube is still intact, the surgeon may make a tiny hole in it and remove the embryo or, if the tube has burst, he may remove part or all of it. Occasionally, ectopics may be treated medically with a drug called methotrexate, which stops the pregnancy from developing. This is only appropriate if the hCG levels are low and the tube hasn't ruptured. The advantage is that surgery is avoided; however, the treatment doesn't always work, can be associated with significant pain, and close follow-up is vital.