An ectopic pregnancy is when an embryo starts to develop outside the uterus. (Ectopic means out of place.) This happens less than 2 percent of the time.

In normal pregnancies, an egg travels from a woman’s ovary to the uterus. It travels down the fallopian tube to get there. Somewhere along the way, the egg gets fertilized by a male sperm. Once inside, the egg attaches to the wall of the uterus. It becomes an embryo and then a fetus. Nine months later, a baby is born.

In ectopic pregnancies, the fertilized egg does not reach the uterus. It starts to grow somewhere else. Most often, that’s in the fallopian tube.

The embryo can’t survive for long outside the uterus. But it can put the mother in danger if it gets too big. It can rupture an organ or cause internal bleeding. Medical steps must be taken right away.

Some women may have no symptoms. They may not even know that they are pregnant. When there are symptoms, they usually come within 8 weeks of conception. Symptoms may include:

Ultrasound can sometimes locate the embryo. Laparoscopy is another option. That’s when a tiny camera with a light is put in the mother’s body. It goes in through a very small incision (cut).

There are many causes for ectopic pregnancies:

Also, the risk for an ectopic pregnancy is higher for women who:

These women should call their health care provider when they miss a menstrual period.

Medicines may be used. But if some time has passed, surgery may be needed. The embryo is removed. Any damage to the mother’s body is repaired. In some rare cases, a fallopian tube or ovary must be removed. But women have another set of these. So the mother may become pregnant again.