Finally, the induction of labor has been recommended in certain anom alies of pregnancy, such as the habitual death of the fcetus without known cause. In such a case, if the antecedents or the constitution of the woman do not call for special treatment, such as in syphilis, we are justi fied in inducing labor.
Certain authorities go further still, and have advocated the induction of labor where the fcetus has died and remains in the uterus. Here we believe the operation to be absolutely contra-indicated, since the presence of the fcetus cannot harm the mother as long as the ovum is intact.
Premature labor being indicated, it remains to study the means at our disposal for induction.
When the indication is a complication or disease threatening the life of the mother, the choice of the time is absolutely subordinated to the gravity of the complication and the state of the mother. In these cases, there being no obstacle to the birth of the fcetus, it runs no more risk than in normal labor; we seek simply to put off the time as long as is possible, as near to term as is possible, in order to increase the infant's chances of survival, remembering chiefly always, however, the interests of the mother, since it is for her life that we are going to interfere. Act, then, neither too soon nor too late, being guided purely by the nature of the complication, and its effect on the mother.
The question is more difficult of decision in case of pelvic deformity. Although we may usually reach a fairly exact idea of the form of the pelvis, it is far otherwise as to the period of pregnancy, and the volume of the fcetus, two conditions of capital importance.
1. The State of have seen already (vide Pregnancy, ol. I.), that it is almost impossible to determine the exact date, and that we are always liable to great error. Of 50 women studied by P. Dubois, in order to find out the possible variations between the supposed date of pregnancy and the real, in 17 cases the difference was 8 days; in 17 others between S and 15 days; in 3 between 15 and 20 days; in 13 be tween 20 to 30 days. The supposed date of pregnancy was placed 8 times before, and 41 times after the real. From these cases, and 100
others, Dubois states that 15 days' error is ordinarily possible.
The gravity of such an error is understood, when we are dealing with a contracted pelvis requiring premature labor between 7 and 7,1 months. The data given by the patients in regard to the last menstruation are often very inexact, and the fcetus being entirely above the cavity, our error would be great if we based an opinion on the development of the abdomen.
2. Volume of the has endeavored to determine this in order, on the one hand, to find out the period of gestation, and, on the other, to recognize the disproportion existing between the fcetus and the possible degrees of pelvic contraction. After having shown that the ra tional history and the main physical signs furnish only illusory data, he concludes that the only absolute is given by the volume of the fcetus. He has endeavored, hence, to measure this, and he has reached the fol lowing conclusions: The fcetus being in a state of flexion, it constitutes an ovoid, one pole formed by the lowest part of the head, and the other by the highest of the breech. By measuring the distance between these two poles, that is to say, the intra-utorine longitudinal axis of the fcetus, Ahlfeld has determined that it represents about one-half of the total foetal length. We may thus obtain quite an exact idea of the true length by measuring the axis. We may measure this axis by means of the pel vimeter, one blade in the vagina to one pole of the ovoid, the other on the abdominal wall over the second pole. Doubling this measurement will give us the true length of the fcetus, and thence the age of the ges tation. In the following tables Ahlfeld's experiments are resumed: The importance of these researches is at once appreciated. The age of gestation and the volume of the foetus being known, there remains simply the other element, the dimension and the form of the pelvis. Let us say here, once for all, that delivery being always more difficult in the generally and regularly contracted pelvis than in the simply flattened or not, it will be necessary to interfere in this case earlier.