[Illustration: FIG. 156.--Extra-uterine pregnancy; tubal abortion. The bleeding is checked by a large coagulum distending and thinning out the tube; the fimbriated opening is greatly distended, but the greater diameter of the clot in the ampulla prevents its escape. Wall of tube averaging 1 millimeter in thickness. Operation. Recovery, July 7, 1896. Natural size. (Kelly. Copyright, 1898, by D. Appleton & Co.)]
[Illustration: FIG. 157.--Coagulum turned out, showing a cast of the tube extending up into the isthmus. On its surface lies the fetus. Natural size. (Kelly. Copyright. 1808, by D. Appleton & Co.)]
When the ovum is destroyed in the tube before rupture takes place, the fetus and the blood may be absorbed; or mummification, adipoceration, or lithopedion-formation may result; or suppuration may occur, with the formation of a pyosalpinx; or, if death of the fetus happens in the early weeks, the tube may be found closed at the ostium abdominale, and filled with blood in which no fetus may be detected. Such cases have been repeatedly described as hematosalpinx, the real origin of the condition in pregnancy not being known. The fetus had been absorbed or broken up and scattered through the blood-mass. Careful microscopic examination of the tube reveals the true condition--a destroyed tubal pregnancy with hemorrhage into the tube. As has already been said, hematosalpinx not caused by tubal pregnancy is very rare.
Coincidently with the development of the tubal pregnancy there occur enlargement of the body of the uterus and decidual transformation of the endometrium. The decidual membrane separates, entire or in fragments, and is discharged from the uterus, after the death of the embryo or during its development, from the eighth to the tenth week. The decidua again forms only when gestation continues undisturbed.
The enlargement of the uterus varies a great deal according to the position of the tubal pregnancy and the course of its development. The interstitial variety is accompanied by the greatest uterine enlargement. When the tubal gestation has reached full time the uterus may measure from 4 to 7½ inches in length.
The increased size of the uterus is most marked in the long diameter. The change of shape does not resemble that which occurs in normal pregnancy.