CONDITION AT ITS INCEPTION.
1. Mechanical Influences.—These are among the most common of the causes which disturb pregnancy. They are usu ally traceable without great difficulty, and in some cases are susceptible of re moval. In the greater number of cases,. however, they persist as long as preg nancy persists.
(a) Pressure of the enlarged or dis placed uterus upon contiguous struct ures. The conditions relating to the dis placed uterus have been described. It is not until after the first half of preg nancy, as a rule, that the pressure of the uterus causes disturbance. One of the most common results of such pressure is disorder in the urinary function. With out discussing the various theories con cerning the albuminuria of pregnancy it is quite evident that pressure is one of the causes, for the albuminuria usually ceases when pregnancy is terminated. When one realizes the susceptibility of the kidneys to floating and wandering it is not strange that they should occasion ally get in the way of the enlarging uterus even when it is progressing in a perfectly normal manner. (See PARTU RITION.) Pressure of the enlarged uterus is also responsible for various other disorders.
Pressure upon the intestines may cause obstruction in those viscera, and it often happens that the constipation which may be so troublesome during pregnancy is traceable to such a cause, especially when the pressure is directed upon the rectum.
Pregnancy plays no part as an eti ological factor in the causation of ap pendicitis. The influence of appendicitis on pregnancy is, on the other hand, well marked. In 7 out of 22 cases abor tion at about the fourth month resulted, either before or after surgical treatment.
The mortality in the 22 cases was: Maternal, 30.4 per cent.; foetal, 47.8 per cent.; consequently pregnancy renders the prognosis of appendicitis more seri ous. Treatment is that of appendicitis, the pregnancy not constituting a contra indication. Early intervention is de sirable. Bouillier (These de Lyon, '97).
Pressure upon the stomach may cause more or less of the indigestion and gas tric discomfort of the later months of pregnancy.
Pressure upon the liver, the gall-blad der, or the bile-ducts may account for jaundice, for nausea, and vomiting. Pressure upon the diaphragm causes some of the discomfort of the latter part of pregnancy, the difficulty in respiration, and sometimes the irregularity of action which is manifested by the heart.
Pressure upon the bladder gives rise to much discomfort in not a few cases. The uterus may so rest upon this viscus that it cannot distend symmetrically as the urine enters it. This may cause such a condition of irritability that there will be a constant desire to micturate. In ability to empty the bladder completely often leads to decomposition of the residual urine, with resulting cystitis, which may persist long after pregnancy has ended. Disorders of the bladder are among the most annoying troubles from which pregnant women suffer. The re sults of the pressure of the enlarged uterus upon nerves and ganglia are not often sufficiently pronounced to excite attention. It is, of course, possible that the sacral nerves and the ganglia of the pelvis may be so encroached upon as to cause numbness or even paralysis of the lower extremities, on the one hand, and interference with the nutrition of the pelvic and abdominal viscera, on the other. The former condition has been observed by most obstetricians of experi ence in more or fewer cases, but I am not aware of any observations which have been made in regard to the latter.
(b) Disturbed circulation, either from immediate pressure upon vascular struct ures or arrest of the current in its ordi nary channel.
The two primary conditions which may result from this factor are and congestion. An2mia is experienced, of course, in the tissues which are imme diately compressed. Such a result is usu ally transient, since the uterus does not normally exert its pressure over the same area for a very long time. It must change its position and the direction of pressure as it enlarges and emerges from the narrow limits of the pelvis• to the less restricted abdomen. If, 'however, it be comes agglutinated to any of the struct ures with which it is brought in contact, that structure may suffer, not only with anaemia, but with the more serious effects of malnutrition which follow as a con sequence. An enlia of the compressed portion is not, of necessity, attended with congestion of the contiguous portions, for the anastomosing circulation may be so perfect that the blood-current will adapt itself to the new and changed con ditions. Such a fortunate result does not always occur; hence the frequent manifestation of congestions in various parts of the body in response to the ob struction which has been placed in the customary channel for the blood.