Overview

An ectopic pregnancy occurs when a fertilized egg implants somewhere other than the main cavity of the uterus. Pregnancy begins with a fertilized egg. Normally, the fertilized egg attaches itself to the lining of the uterus.

An ectopic pregnancy most often occurs in one of the tubes that carry eggs from the ovaries to the uterus (fallopian tubes). This type of ectopic pregnancy is known as a tubal pregnancy. In some cases, however, an ectopic pregnancy occurs in the abdominal cavity, ovary or neck of the uterus (cervix).

An ectopic pregnancy can't proceed normally. The fertilized egg can't survive, and the growing tissue might destroy various maternal structures. Left untreated, life-threatening blood loss is possible.

Early treatment of an ectopic pregnancy can help preserve the chance for future healthy pregnancies.

Symptoms

At first, an ectopic pregnancy might not cause any signs or symptoms. In other cases, early signs and symptoms of an ectopic pregnancy might be the same as those of any pregnancy — a missed period, breast tenderness and nausea.

If you take a pregnancy test, the result will be positive. Still, an ectopic pregnancy can't continue as normal.

Light vaginal bleeding with abdominal or pelvic pain is often the first warning sign of an ectopic pregnancy. If blood leaks from the fallopian tube, it's also possible to feel shoulder pain or an urge to have a bowel movement — depending on where the blood pools or which nerves are irritated. If the fallopian tube ruptures, heavy bleeding inside the abdomen is likely — followed by lightheadedness, fainting and shock.

When to see a doctor

Seek emergency medical help if you experience any signs or symptoms of an ectopic pregnancy, including:

  • Severe abdominal or pelvic pain accompanied by vaginal bleeding
  • Extreme lightheadedness or fainting
  • Shoulder pain

Causes

A tubal pregnancy — the most common type of ectopic pregnancy — happens when a fertilized egg gets stuck on its way to the uterus, often because the fallopian tube is damaged by inflammation or is misshapen. Hormonal imbalances or abnormal development of the fertilized egg also might play a role.

Risk factors

Up to an estimated 20 in every 1,000 pregnancies are ectopic. Various factors are associated with ectopic pregnancy, including:

  • Previous ectopic pregnancy. If you've had one ectopic pregnancy, you're more likely to have another.
  • Inflammation or infection. Inflammation of the fallopian tube (salpingitis) or an infection of the uterus, fallopian tubes or ovaries (pelvic inflammatory disease) increases the risk of ectopic pregnancy. Often, these infections are caused by gonorrhea or chlamydia.
  • Fertility issues. Some research suggests an association between difficulties with fertility — as well as use of fertility drugs — and ectopic pregnancy.
  • Structural concerns. An ectopic pregnancy is more likely if you have an unusually shaped fallopian tube or the fallopian tube was damaged, possibly during surgery. Even surgery to reconstruct the fallopian tube can increase the risk of ectopic pregnancy.
  • Contraceptive choice. Pregnancy when using an intrauterine device (IUD) is rare. If pregnancy occurs, however, it's more likely to be ectopic. The same goes for pregnancy after tubal ligation — a permanent method of birth control commonly known as "having your tubes tied." Although pregnancy after tubal ligation is rare, if it happens, it's more likely to be ectopic.
  • Smoking. Cigarette smoking just before you get pregnant can increase the risk of an ectopic pregnancy. And the more you smoke, the greater the risk.

Complications

When you have an ectopic pregnancy, the stakes are high. Without treatment, a ruptured fallopian tube could lead to life-threatening bleeding.

Prevention

You can't prevent an ectopic pregnancy, but you can decrease certain risk factors. For example, limit your number of sexual partners and use a condom when you have sex to help prevent sexually transmitted infections and reduce the risk of pelvic inflammatory disease. Quitting smoking before you attempt to get pregnant may also reduce your risk.

Jan. 20, 2015
References
  1. Frequently asked questions. Pregnancy FAQ 0155. Ectopic pregnancy. American College of Obstetricians and Gynecologists. http://www.acog.org/Patients/FAQs/Ectopic-Pregnancy. Accessed Dec. 9, 2014.
  2. Cunningham FG, et al. Williams Obstetrics. 24th ed. New York, N.Y.: The McGraw-Hill Companies; 2014. http://accessmedicine.mhmedical.com/book.aspx?bookid=1057. Accessed Dec. 9, 2014.
  3. Tulandi T. Clinical manifestations, diagnosis, and management of ectopic pregnancy. http://www.uptodate.com/index. Accessed Dec. 9, 2014.
  4. Tulandi T. Incidence, risk factors, and pathology of ectopic pregnancy. http://www.uptodate.com/index. Accessed Dec. 9, 2014.
  5. Harms RW (expert opinion). Mayo Clinic, Rochester, Minn. Dec. 15, 2014.