Ectopic pregnancy is attachment (implantation) of a fertilized egg in an abnormal location.

• Women may have abdominal pain and vaginal bleeding.
• Ultrasonography is done, mainly to determine the location of the fetus.
• Usually, surgery is done to remove the fetus and placenta, but sometimes a single dose of methotrexate is used to end the ectopic pregnancy.

Normally, an egg is fertilized in the fallopian tube and becomes implanted in the uterus. However, if the tube is narrowed or blocked, the fertilized egg may never reach the uterus. Sometimes the fertilized egg implants in tissues outside of the uterus, resulting in an ectopic pregnancy. Ectopic pregnancies usually develop in one of the fallopian tubes (as a tubal pregnancy) but may develop in other locations.

A fetus in an ectopic pregnancy sometimes survives for several weeks. However because tissues outside the uterus are unable to provide the necessary blood supply and support, ultimately the fetus does not survive. The structure containing the fetus typically ruptures after about 6 to 16 weeks, long before the fetus is viable. When an ectopic pregnancy ruptures, bleeding may be severe and even life threatening. The later the tube ruptures, the worse the blood loss, and the higher the risk of death.

One of 100 to 200 pregnancies is an ectopic pregnancy. Risk factors for an ectopic pregnancy include having had a disorder of the fallopian tubes, pelvic inflammatory disease, a previous ectopic pregnancy, exposure to diethylstilbestrol as a fetus, or a tubal ligation (a sterilization procedure) that was unsuccessful or has been surgically reversed.

Symptoms

Symptoms include vaginal bleeding or spotting, cramping or pain in the lower abdomen, or both. If the fallopian tube ruptures, the woman usually feels severe, constant pain in the lower abdomen. If the woman has significant blood loss she may faint, sweat, or feel light-headed.

Diagnosis

Doctors suspect an ectopic pregnancy in women who are of reproductive age and have lower abdominal pain or vaginal bleeding. In such women, a pregnancy test is done. If the pregnancy test is positive, ultrasonography is done using a probe inserted into the vagina. If ultrasonography detects a fetus in a location other than the uterus, the diagnosis is confirmed. If ultrasonography does not detect a fetus anywhere, ectopic pregnancy is still possible, or the pregnancy may be in the uterus but be at too early a stage to be seen. Doctors do blood tests to measure a hormone produced by the placenta. This test can help doctors determine whether the pregnancy is too early for the fetus to be visible in the uterus.

If needed to confirm the diagnosis, doctors may use a viewing tube called a laparoscope, inserted through a small incision just below the navel. This procedure enables them to view an ectopic pregnancy directly.

Treatment

An ectopic pregnancy must be ended as soon as possible to save the life of the woman. In most women, the fetus and placenta must be removed surgically, usually with a laparoscope but sometimes through an incision in the abdomen (in a procedure called laparotomy). Rarely, the uterus is so damaged that a hysterectomy is required.

Sometimes the drug methotrexate, usually given in a single injection, can be used instead of surgery. The drug causes the ectopic pregnancy to shrink and disappear. Occasionally, surgery is needed in addition to methotrexate.

Ectopic Pregnancy: A Mislocated Pregnancy Normally, an egg is fertilized in the fallopian tube and becomes implanted in the uterus. However, if the tube is narrowed or blocked, the egg may move slowly or become stuck. The fertilized egg may never reach the uterus, resulting in an ectopic pregnancy. An ectopic pregnancy may be located in many different places, including a fallopian tube, an ovary, the cervix, and the abdomen.

Last full review/revision December 2008 by Edmund F. Funai, MD