An ectopic pregnancy is an abnormal pregnancy that occurs outside the womb (uterus). The baby (fetus) cannot survive, and often does not develop at all in this type of pregnancy.
Tubal pregnancy; Cervical pregnancy; Abdominal pregnancy
Causes, incidence, and risk factors
An ectopic pregnancy occurs when a pregnancy starts outside the womb (uterus). The most common site for an ectopic pregnancy is within one of the tubes through which the egg passes from the ovary to the uterus (fallopian tube). However, in rare cases, ectopic pregnancies can occur in the ovary, stomach area, or
An ectopic pregnancy is often caused by a condition that blocks or slows the movement of a fertilized egg through the fallopian tube to the uterus. This may be caused by a physical blockage in the tube by hormonal factors and by other factors, such as smoking.
Most cases of scarring are caused by:
- Past ectopic pregnancy
- Past infection in the fallopian tubes
- Surgery of the fallopian tubes
Up to 50% of women who have ectopic pregnancies have had swelling (inflammation) of the fallopian tubes (salpingitis) or pelvic inflammatory disease (
Some ectopic pregnancies can be due to:
- Birth defects of the fallopian tubes
- Complications of a
- Scarring caused by previous pelvic surgery
The following may also increase the risk of ectopic pregnancy:
- Age over 35
- Having had many sexual partners
In vitro fertilization
In a few cases, the cause is unknown.
Sometimes, a woman will become pregnant after having her tubes tied (
Ectopic pregnancy is also more likely in women who have:
- Had surgery to reverse tubal sterilization in order to become pregnant
- Had an intrauterine device (IUD) and became pregnant (very unlikely when IUDs are in place)
Ectopic pregnancies occur in 1 in every 40 to 1 in every 100 pregnancies.