II. Hemorrhagic endometritis, caused in part by changes in the constitution of the blood, is not an uncommon symptom in the course of acute infectious diseases in the non-gravid state. In pregnancy this symptom is of more constant occurrence, just as it is of graver prognostic moment, both with reference to the mother and to the child.
I. The death of the foetus and the interruption of pregnancy may result from the operation of a variety of etiological factors.
1. The foetus usually dies in consequence of the elevation of maternal temperature. The case is a veritable example of that condition which H. C. Wood of Philadelphia terms heat-stroke. The normal foetal temperature is slightly more elevated than the maternal. The foetus in its membranes, surrounded by maternal tissues, must possess at least the same temperature as the maternal body. But it has its own heat-producing apparatus in addition. A very slight elevation of the maternal temperature produces a disproportionate rise in the temperature of the foetal body. Kaminsky31 has shown that an elevation of maternal temperature to 104° F. imperils foetal life. Increased frequency of the pulsation of the foetal heart and abnormally active foetal movements are followed by diminished cardiac and muscular activity, and the foetus dies. The autopsy reveals the characteristic lesions of heat-stroke.
31 Moskauer Med. Z., 1867, Nos. 13-19.
2. Runge32 has demonstrated the occurrence of foetal death from asphyxia when the maternal blood-pressure is seriously lowered. This lowering of the maternal blood-pressure occurs as the result of diminution in the force and frequency of the heart's action observed in the course of acute infectious diseases or from the sudden loss of blood. Asphyxia may also be caused by structural changes in the epithelium covering the foetal placenta, due to the state of the maternal blood.
32 Arch f. Gyn., Bd. xii. p. 16.
3. The foetus may perish in consequence of infection with the specific poison of the acute disorder. Death as the result of acute infection has been observed in variola and relapsing fever.
4. Pregnancy may be interrupted, independently of the condition of the foetus, as the result of the thermic irritation of the uterine muscular fibre by the maternal blood. Spiegelberg on a priori grounds asserted the possibility of this event. Runge33 has since demonstrated by experimental methods its actual occurrence.
33 Volkmann's Sammlung, No. 174; Arch. f. Gyn., Bd. xii. p. 16.
II. Hemorrhagic endometritis in the course of acute infectious diseases complicating pregnancy has been demonstrated by Slavjansky's34 researches. In cholera this symptom is observed with relative frequency. Following hemorrhage into the decidua, according to the time, extent, and site, pregnancy may be immediately interrupted, or secondarily as the result of the pathological changes in the placenta or membranes induced by the extravasated blood. The hemorrhage may be so severe as to jeopardize the life of the mother.