A blue baby or cyanosis neonatorum is the result should this valve fail to close. The venous blood commingles with the arterial blood, and death is the result sooner or later.
The umbilical cord is made up of two arteries and one vein. It is from two to four feet in length, attached at one extremity to the placenta, and at the other to the navel of the child. This is the medium of the circulation between the placenta and the fetus.
The membranes all unite before birth to form one thick, tenacious covering for the child, and also for the cord and fetal surface of the placenta.
This incloses the fluid—the liquor amnii—which serves to protect the fetus from blows or sudden jars. The membranes and the contained fluid form what is known as the “bag of waters.” Not rupturing before birth, they make what is called a veil or caul over the child’s face, to which is attached various superstitions, such as the gift of “second sight,” clairvoyance, etc.
Healthy nutrition of the fetus depends entirely upon the mother. The placenta not only represents the digestive organs, but the lungs of the fetus. Consequently upon the condition of the mother depends the condition of the child. It has no other means of getting nutriment, or of disposing of waste material. After birth it has the same advantage as the adult in correcting errors in diet and nutrition by elimination. The skin, with its miles of perspiratory ducts, then conveys effete matter from the system, the lungs keep up by respiration a constant interchange of oxygen for carbon, while the liver, kidneys and bowels are active in their functions of depurition. In utero these functions are all dormant, consequently giving the fetus a disadvantage for healthy growth. Mothers often show a great solicitude about diet and conditions during lactation, while they are comparatively indifferent to these matters during pregnancy.
Especially should they breathe deeply, and that, too, of pure air. Trall says: “If the mother does not breathe sufficiently the child must suffer. Many a mother gives birth to a frail, scrofulous child, for no reason except that during the period of gestation she is too sedentary and plethoric. I have known women of vigorous constitutions, who had given birth to several healthy children, become the mothers of children so puny and scrofulous that it was impossible for them to be raised to adult age. The reason is that the mother is obstructed in her respiratory system, and although she may breathe enough to sustain her own organization in a fair condition, she does not inhale oxygen enough to supply the needs of an intra-uterine being. Many ‘still births’ are explainable on this principle.”
The duration of pregnancy is nine calendar months or ten lunar months, about 280 days. If the date of impregnation is not known, the count should be made from the beginning of the last menstruation, and add eight days on account of the possibility of its occurring within that period. It is possible in some diseased conditions for the period to extend much beyond this time. I knew one case of amniotic dropsy where pregnancy extended forty-four weeks.
Helen Idleson, M. D., in the Med. Wochenschrift, sums up the results of her investigations as follows: “1. The duration of pregnancy amounts to 278 days, or nearly 40 weeks. 2. The sex of the infant influences the duration, this being longer in female infants. (?) 3. The heavier the child, the longer is the duration. (?) 4. The duration is longer in multipara than in primipara. 5. The younger the woman the longer is the duration. 6. The duration is longer in married than in unmarried women. 7. The first movements of the child are felt, on an average, on the one hundred and thirty-fifth day, but later in primipara than in multipara.
“The growth of the embryo after fecundation is very rapid. On the tenth day it has the appearance of a semi-transparent, grayish flake. On the twelfth day it is nearly the size of a pea, filled with fluid, in the middle of which is an opaque spot, presenting the first appearance of an embryo, which may be clearly seen as an oblong or curved body, and is plainly visible to the naked eye on the fourteenth day. The twenty-first day the embryo resembles an ant or a lettuce-seed; its length is from four to five lines and its weight from three to four grains. Many of its parts now begin to show themselves, especially the cartilaginous beginnings of the spinal column, the heart, etc.
“The thirtieth day the embryo is as large as a horse-fly, and resembles a worm, bent together. There are as yet no limbs, and the head is larger than the rest of the body. When stretched out it is nearly half an inch long. Toward the fifth week the heart increases greatly in proportion to the remainder of the body, and the rudimentary eyes are indicated by two black spots turned toward the sides, and the heart exhibits its external form, bearing a close resemblance to that in the adult.