Ectopic Pregnancy: Diagnosis and Treatment

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:

  1. Early pregnancy detection -- The availability of sensitive pregnancy tests that can detect all pregancies much earlier than before means that ectopic pregnacies are detected at a time prior to advanced tubal damage and rupture.
  2. Ultrasound monitoring -- Modern and improved ultrasound equipment permits detailed evaluation of early pregnancies, including the location of the pregnancy and the actual flow of blood to the uterus/tube (which helps assess the risk of blood loss from ectopic rupture).
  3. Improved surgical techniques -- Laparoscopy (see below for definition) and other surgical techniques have been refined over the years, allowing for the safer removal of tubal pregnancies and improved tubal healing.
  4. Improvements in anesthesia and blood products -- Refinements in anesthesia, as well as safer and more widely available blood for transfusion, have dramatically improved surgical outcomes.

Risk Factors and Causes

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:

  1. Pelvic inflammatory disease (PID) -- An infection of the female reproductive tract, PID can cause damage to and scarring of the fallopian tubes. PID is the single greatest risk factor for an ectopic pregnancy.
  2. Endometriosis -- A disease whereby tissue similar to the uterine lining grows outside of the uterine cavity, endometriosis can cause pelvic scar tissue to form, increasing the possibility of tubal damage and dysfunction.
  3. Prior pelvic surgery -- Surgery within the pelvis increases the odds of scar formation around the fallopian tubes, again increasing the possibility of tubal damage and dysfunction.
  4. Previous ectopic pregnancy -- A history of a prior ectopic pregnancy increases the chances of a subsequent ectopic pregnancy (to an average of 15%).
  5. Abnormalities of the fallopian tubes present since birth.
  6. Cigarette smoking -- Nicotine can damage the hair-like cells within the fallopian tube, making entrapment of the fertilized egg within the tube more likely.
  7. Usage of certain types of intrauterine devices (known commonly as IUDs) for birth control.
  8. Use of certain hormonal preparations, including progestin-only oral contraceptive pills and possibly fertility drugs and treatments.

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.

Signs and Symptoms

Most women with an ectopic pregnancy exhibit the following signs and symptoms: