Normally, at the beginning of a pregnancy, the fertilized egg travels from the fallopian tube to the uterus, where it implants and grows. In about 2% of diagnosed pregnancies, however, the fertilized egg attaches to an area outside of the uterus, which results in an ectopic pregnancy (also known as a tubal pregnancy or an extrauterine pregnancy).⁵

An ectopic pregnancy cannot support the life of a fetus for very long. However, an ectopic pregnancy can grow large enough to rupture the area it occupies, cause heavy bleeding, and endanger the mother. A woman with signs or symptoms of an ectopic pregnancy requires immediate medical care.

In most ectopic pregnancies, the fertilized egg has implanted in a fallopian tube.

On rare occasions:

• The egg attaches and grows in an ovary, the cervix, or the abdominal cavity (outside of the reproductive system).
• One or more eggs grow in the uterus, and one or more grow in a fallopian tube, the cervix, or the abdominal cavity. This is called a heterotopic pregnancy.

Although extremely rare, there are reports of women developing abdominal ectopic pregnancies after surgical removal of the uterus (hysterectomy).⁶

See a picture of locations where an ectopic pregnancy can develop.

Complications of ectopic pregnancy

Ectopic pregnancy can damage the fallopian tube, which can make it difficult to become pregnant in the future.

Ectopic pregnancies are usually detected early enough to prevent life-threatening complications such as severe bleeding. A ruptured ectopic pregnancy requires emergency surgery to prevent heavy bleeding into the abdomen. The affected tube is partially or fully removed. For more information, see the Surgery section of this topic.