tubal pregnancy, an ectopic pregnancy in which the conceptus implants in the fallopian tube. Approximately 2% of all pregnancies are ectopic; of these, approximately 90% are tubal. Tubal pregnancy seldom occurs in primigravidas. The most important predisposing factor is prior tubal injury. Pelvic infection, scarring and adhesions from surgery, or intrauterine device complications may result in damage that diminishes the motility of the tube. Transport of the ovum through the tube after fertilization is slowed, and implantation takes place before the conceptus reaches the uterine cavity. Most often the tube, which cannot long contain the growing fetus, ruptures, precipitating an intraperitoneal hemorrhage. If not stopped, the hemorrhaging can lead rapidly to shock and often death. Some conceptuses apparently die and are resorbed in the tube. Diagnosis of tubal pregnancy is often difficult. With rupture of the fallopian tube, women commonly experience sudden sharp pain in one side of the lower abdomen, but signs and symptoms of tubal pregnancy are insidiously variable, and the classic triad of amenorrhea, pelvic pain, and a tender adnexal mass are present only 50% of the time. Recovery of blood from the cul-de-sac by means of culdocentesis is highly suggestive of a ruptured fallopian tube and tubal pregnancy; it requires immediate surgical exploration of the abdomen. Absence of blood on culdocentesis does not rule out the presence of an unruptured tubal pregnancy. Laparotomy may be required, particularly if a woman’s pregnancy test is positive, the pelvic findings are suggestive, and sonography of the pelvis cannot demonstrate an intrauterine pregnancy. Because of the lethal potential of an undiagnosed tubal pregnancy, women who report any of the characteristic symptoms early in their pregnancies, particularly during the time before the existence of a normal intrauterine pregnancy can be confirmed, must be considered susceptible. In women who have a history of prior pelvic disease and in those who have symptoms or signs of tubal pregnancy, emergency treatment requires an immediate IV infusion via a large-bore IV catheter, type and crossmatch of blood for blood replacement, and treatment of shock as necessary. In very early ectopic pregnancy, treatment by methotrexate is 90% effective. Otherwise, treatment is surgical and involves laparotomy, removal of the entire products of conception and any intraperitoneal blood present, and the removal or repair of the involved tube. Conditions that predispose to a first tubal pregnancy also predispose to a second; a woman who has had one tubal pregnancy has one chance in five of having another in a subsequent pregnancy. Depending on the location of the developing embryo, the condition is classified as an ampullary, fimbrial, or interstitial tubal pregnancy.
