ectopic pregnancy

Med.

the development of a fertilized ovum outside the uterus, as in a Fallopian tube. Also called extrauterine pregnancy.

[1925-30]

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or extrauterine pregnancy

Condition in which a fertilized egg is imbedded outside the uterus (see fertilization).

Early on, it may resemble a normal pregnancy, with hormonal changes, amenorrhea, and development of a placenta. Later, most patients have pain as the growing embryo stretches the structure it is attached to. Rupture may cause life-threatening bleeding. A tubal pregnancy may result from obstruction of the egg's passage through the fallopian tube. In an ovarian pregnancy, the egg is fertilized before it leaves the ovary. Implantation elsewhere in the abdomen is an abdominal pregnancy.

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▪ pathology

also called  Extrauterine Pregnancy,  

      condition in which the fertilized ovum (egg) has become imbedded outside the uterine cavity. The site of implantation is usually designated—e.g., tubal, abdominal, or ovarian ectopic pregnancy.

      In tubal ectopic pregnancy the ovum becomes implanted in one of the fallopian tubes. This condition is not uncommon, occurring about once in 250 to 300 pregnancies and more frequently in blacks than Caucasians. It may be brought about by anything that interferes with the propulsion of the fertilized ovum from the fallopian tube toward the uterine cavity—e.g., inflammation of the fallopian tube, developmental malformation of the sacs within its canal, or kinking of the tube. If transport to the uterus is sufficiently delayed, the ovum becomes too large for easy passage and becomes imbedded in the wall of the fallopian tubule. Tubal ectopic pregnancy in early stages is similar in some respects to normal pregnancy; implantation of the ovum in the tubal wall is much like that which occurs in the uterus. Also, as pregnancy begins to develop, placental tissue, like that of intrauterine gestation, develops. Eventually, however, the placenta removes itself from the tubal wall, and the fetus is discharged as a whole mass or in smaller fragments if it disintegrates. The symptoms of tubal ectopic pregnancy in early stages are so minor that they might be ignored by the patient. Depending upon the part of the tube in which the ovum has become implanted, the tubal pregnancy can abort, through tubal rupture, any time from 6 to 18 weeks after cessation of menstrual periods (on occasion there will be no history of missed periods). Once the fetus begins to disintegrate or is discharged, bleeding will follow. Pain is associated at some time with nearly every tubal pregnancy. During the final stages of separation and expulsion in a tubal pregnancy, the patient experiences pain and bleeding. Surgical exploration of the abdomen and removal of the affected tube and replacement of lost blood are often essential to prevent death.

      Ovarian ectopic pregnancy is a relatively rare condition in which the ovum is fertilized before its discharge from the follicle. Symptoms, termination, and treatment are similar to those of tubal pregnancy, but gestation may progress slightly further before rupture and bleeding occur.

      Abdominal ectopic pregnancy occurs when the placenta is attached to some part of the peritoneal cavity other than the uterus or tube. While a few of these pregnancies are a result of implantation in the abdominal lining, most are the result of expulsion of a tubal pregnancy. The condition can be suspected in the first three months of pregnancy if pain and bleeding are experienced. Abdominal pregnancy can reach term. Prompt surgical removal of the fetus is necessary, because an unrecognized and untreated abdominal pregnancy can result in infection or calcification leading to the formation of a lithopedion (calcified dead fetus) and death of the mother.

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