Ectopic pregnancy

… one should regard sudden collapse associated with symptoms of abdominal hemorrhage in a woman during the childbearing period as prima facie evidence of a ruptured tubal pregnancy. By so doing, and operating promptly in suitable cases, a number of lives will be saved which otherwise would inevitably be lost. J. Whitridge Williams (1866–1931) Obstetrics: A Text-Book for the Use of Students and Practitioners, New York: D. Appleton and Company, 1903, p. 553. The initiation of a normal pregnancy requires ex-quisitely timed coordination of several endocrine-sensitive tissues. After fertilization of the ovum in the fallopian tube, cleavage and embryonic development occur, followed by uterine implantation approximately six days later. Following fertilization and implantation, the syncytiotrophoblast begins to produce human chorionic gonadotropin (hCG), which eventually rescues and maintains the corpus luteum beyond its normal 14-day life span. When this course of physiologic events occurs normally, a pregnancy can progress, allowing the fetus to develop until birth. The development of an ectopic pregnancy is an aberration of this process, in which embryonic implantation occurs outside of the uterus, most commonly in the fallopian tube but also in extratubal locations. Ectopic pregnancy is an extremely serious threat to the general and reproductive health of a woman. The objective of this chapter is to provide a comprehensive discussion of the contemporary approach to ectopic pregnancy. Diagnosis and treatment options and the epidemiology and pathophysiology of the condition are also reviewed.