The cultivation of self-control and of a resolute spirit capable of enduring pain are of great help to the mother as well as to her child. Unreasoning fears, even the so-called " maternal impressions," are to be avoided, as they act unfavourably on the nerves, on the sleep, on the appetite, and, later, on the labour. Pregnancy and delivery are normal processes, and the rare accidents which occasionally occur may almost invariably be avoided by the timely consultation of a physician. With regard to the " maternal impressions," not a single case has as yet been shown which could stand the test of serious criticism.
The doctrine of " maternal impressions " has no justification whatever. Some physicians may believe that deformities in the infant may result from sights or frights that have occurred in the mother's experience, but all the evidence of scientific embryology is against them. Nervous women should take comfort in knowing that these things arc impossible. The possibility of inheritance of deformities is another matter. Many slight variations are passed down for generations. In any event, self-tormenting brooding does more harm to mother and child than the likelihood of any inheritance. It is to be borne in mind that operations, especially on the teeth, may occa sionally cause premature labour in very excitable and sensitive persons. But if the operation be urgent, or if the sleep is disturbed by pain, it is more detrimental to omit the operation than to have it performed.
A pregnant woman should be careful about taking medicines which had been prescribed for her previously. Some medicines, such as morphine, may affect the infant injuriously. The resistance of the infant depends not only upon the properties inherited from its parents, hut also upon influences which affect the mother during her pregnancy.
The laws determining the sex of the foetus are evidently very intricate ; at any rate, they are known in part only. Arbitrary choice of sex in procreation is not yet possible Nor is it always possible to determine the sex of the infant before birth, although the size of the foetus, the strength of its movements, and the fcetal heart-sounds may afford ground for fairly accurate guessing on the part of the physician.
Poisons and bacteria cannot readily enter the mother's body during pregnancy. The infant is, to a certain extent, protected by the interposi tion of the placenta, and it is guarded against coarser external injuries by the decidua and by the amniotic sac filled with fluid, provided the entire ovum was favourably lodged in the uterine membrane. The lodging of the ovum too near the mouth of the womb may result in miscarriage. If the OVUM, after fecundation, fails to descend to the womb, it may remain either in the tube or in the ovary, or it may later enter the abdominal cavity. Ac cording to the position of the ovum, these abnormalities give rise to a tubal, an ovarian, or an abdominal pregnancy.
These are usually very serious accidents, because the mother is exposed to the danger of rupture of the thin walls of the organ, accompanied with profuse internal haemorrhages and extremely severe pain. Operation some times saves the patient's life, or she may recover without operative inter ference. Only a judicious physician or surgeon can decide. See also the article on REPRODUCTION, as well as the chapter on THE ORGANS OF GENERATION (pp. 164-169).