As the rule is to operate in all cases of tubal tumor, the proper treatment will probably be applied, notwithstanding the uncertainty or mistake of diagnosis.
CHAPTER XXVI.
TUBAL PREGNANCY.
Tubal pregnancy occurs when a fecundated ovum is developed in the Fallopian tube.
Fecundation may take place in the Fallopian tube, because spermatozoa may pass through the uterus and the tube into the pelvic cavity; but unless something occurs to arrest the passage of the fertilized ovum into the uterus, a normal uterine pregnancy will result. It is said by Webster that predisposition to tubal pregnancy is due to a “developmental fault, whereby there is reversion, either of structure or reaction tendency, in the tubal mucosa to an earlier type in mammalian evolution.”
In other words, decidual changes, following the fertilization of the ovum, may in some women occur in the mucous membrane of the Fallopian tubes as well as in that of the uterus. If this condition is present in any case, and at the same time something occurs to impede the passage of the ovum into the uterus, a tubal pregnancy may take place.
Interference with the passage of the ovum along the tube has been attributed to a variety of causes. Chronic salpingitis is a frequent cause. It destroys the cilia of the epithelial cells of the tubal mucosa. It produces thickening of the tubal walls, and causes peritoneal adhesions that impede the normal peristaltic action of the tube.
Obstruction to the passage of the ovum may also be caused by polypi or tumors of the tube; by tumors external to the tube pressing upon it; by displacement and hernia of the tube; by diverticula of the tube; or by abnormal foldings of the tubal wall. Tubal pregnancy has occurred in tubes in which no lesions whatever could be discovered by the most careful examination.
It seems probable that practically all pregnancies that occur outside of the uterus originate in the Fallopian tube.