The word "ectopic" means "out of place." An ectopic pregnancy is a pregnancy that is not growing in the usual location (the uterine cavity). Ectopic pregnancies can occur in a number of abnormal locations, each with different characteristic growth patterns and treatment options. The most common sites for an ectopic pregnancy are the

1. ampullary (mid) portion of the fallopian tube (80-90%),
2. isthmic (area closer to the uterus) portion of the fallopian tube (5-10%),
3. fimbrial (distal end away from the uterus) portion of the fallopian tube (about 5%),
4. cornual (within the uterine muscle) portion of the fallopian tube (1-2%),
5. abdomen (1-2%),
6. ovary (less than 1%), or
7. cervix (less than 1%).

Ectopic pregnancies are dangerous. Any growing pregnancy requires a large nutrient source (blood supply) and develops many communications with the mother's (pregnant woman's) vascular system (blood vessels). The uterus is uniquely designed to accommodate this development, so that when a pregnancy begins to grow in other surrounding structures the vascular communication may be inadequate.

Furthermore, as the pregnancy grows in size the uterus dramatically changes shape and size. Surrounding structures are usually not able to change as readily so they are often damaged or "ruptured" by a contained growing ectopic pregnancy. When the ectopic pregnancy outgrows the limits of the space enclosing it, there can be life threatening bleeding.

Ectopic pregnancies were initially described in the 11th century and for a long time were universally fatal events for the mother. Initial treatments (in the old days) were desperate primitive attempts designed to destroy the growing pregnancy without sacrificing the mother's life. These included

• starvation (hoping that the fetus would starve before the mother),
• bleeding (intentional exsanguination of the mother in the hope that the fetus would die and the mother could be spared),
• administration of strychnine (to preferentially destroy the fetus), and
• administration of electricity into the growing gestational (pregnancy) sac.

Surgery attempted in the 1800s resulted in a high maternal mortality rate (greater than 80% of women died from the surgery alone) so it was rarely performed.

Since these times, several developments in the management of ectopic pregnancies have led to remarkable success in "saving the mother's life." Further developments recently have resulted in a shift in focus (concern) from saving the mother's life to additionally "saving the woman's fertility." The decrease in maternal morbidity (death) from ectopic pregnancy has been largely due to development and refinement of

1. early detection of pregnancy, primarily with the development of sensitive pregnancy tests (hCG assays) and characterization of the normal rate of rise in the circulating human chorionic gonadotropin (hCG) concentrations during early pregnancy
2. aseptic (sterile) technique, where surgeries are now performed in operating rooms with protocols for cleansing, scrubbing and gowning that inhibit transmission of infection
3. antibiotics to fight infections, with tremendous advances in infectious disease and antibiotic research during the past few decades
4. anesthetic agents, with new agents allowing increasingly safe administration and a greater understanding of intraoperative patient monitoring
5. availability of blood or blood products for perioperative transfusions, including advances in terms of blood collection, storage and determination of compatibility with the recipient
6. surgical techniques to identify and remove the ectopic pregnancy, such as salpingectomy and salpingostomy (when appropriate)

At this point in time, gynecologists appropriately attempt to diagnose ectopic pregnancy early (since greater treatment options are available) and treat the ectopic pregnancy in such a way as to maximize fertility and minimize the risk for a future ectopic.