by Scott J. Roseff, MD, FACOG
An ectopic pregnancy is a pregnancy that grows outside of the normal location, namely the uterus. Often called a "tubal pregnancy," the majority (about 97%) of ectopic pregnancies occur in the fallopian tube. Ectopic pregnancies can also occur in the ovary, cervix, or abdominal cavity, but this is rare. For the purpose of this article, the terms "ectopic pregnancy" and "tubal pregnancy" will be used interchangeably.
The danger of ectopic pregnacy lies in the fact that a fallopian tube is not large enough or sufficiently elastic to accommodate a growing embryo, and thus may rupture as the ectopic pregnancy grows. An ectopic pregnancy is considered to be a medical emergency because tubal rupture can cause severe internal bleeding that may lead to shock and even the death of the mother.
The incidence of ectopic pregnancy is rising; about 7 per 1,000 reported pregnancies in the United States are ectopic. However, since the 11th century when the condition was first described the death rate from ectopic pregnancy has declined significantly. This is due to the advent of modern techniques permitting early diagnosis and treatment. The current maternal mortality rate due to ectopic pregnancy is less than 1 per 2,500 cases. This low death rate may be attributed to several important modern developments, including:
Risk factors for the development of an ectopic pregnancy generally relate to processes that damage or narrow the fallopian tubes, resulting in a situation whereby the fertilized egg can not travel the length of the tube. Well-recognized risk factors for ectopic pregnancy include:
Many times, however, there are no obvious predisposing factors for ectopic gestation. Therefore, many physicians agree with the philosophy that any woman of reproductive age who is pregnant should be considered to have an ectopic pregnancy until proven otherwise.
Most women with an ectopic pregnancy exhibit the following signs and symptoms: