You will recall that while within the uterus, the baby received his nourishment and oxygen and gave up waste material through the placenta. Accordingly, his organs of digestion, respiration and excretion are imperfectly developed at birth and are capable of functioning only within very narrow limits at first.
His respirations are usually established immediately after birth, when he cries vigorously, for his lungs are thereby filled with air. The other functions are established more gradually and the care of the baby must be such that the immature, unused organs will have their development promoted through activity and yet not be overtaxed.
The Baby’s Condition at Birth. The newborn baby boy weighs from seven and a quarter to seven and a half pounds and is about twenty inches long, girl babies being perhaps a little smaller. His body is well rounded and his flesh firm. The skin is a deep pink, or even red, and is covered with the cheesy substance called vernix caseosa, which is likely to be thickly deposited over the back and in folds of the skin and creases, as in the thighs and under the arms. Some babies still have, when born, the fine downy hair on parts or all of the body, that they had before birth.
The head and abdomen are relatively large, the chest narrow and the limbs short. The legs are so markedly bowed that the soles of the baby’s feet may nearly or quite face each other, but they finally assume a normal position. The bones are still soft and the entire body is, therefore, very flexible. Some of the bones which unite later in life and make the adult skeleton firm and rigid, are separate at birth.
Most newborn babies have faded blue eyes, the permanent color appearing gradually, but the amount and color of the hair varies greatly, some babies being bald, while others have abundant hair from the beginning.
The shape of the baby’s head is often badly distorted at birth, being so long from chin to crown that the mother is deeply concerned. But you may rest quite assured that even though badly misshapen, your baby’s head in the course of a few days will assume the lovely, rounded contour so characteristic of babyhood. The temporary deformity of the head is caused by a molding and overlapping of the bones of the skull as it is forced through the narrow part of the pelvis, the inlet, that we learned about in Chapter III. About the middle of the top of the head you will be able to feel a soft, diamond shaped spot and farther back another soft spot, smaller than the one in front and somewhat triangular in its outline. These soft places are openings between the bones of the skull and are called the anterior and posterior fontanelles. They always may be felt on the new baby’s head.
Growth and Development. The physical progress which is made during the first year by average, normal babies who are satisfactorily nourished and cared for is fairly uniform and the average rate of this progress is somewhat as follows:
Weight. There is a loss in weight of 6 to 10 ounces during the first week of life, after which the baby usually gains from 4 to 8 ounces each week, during the first five months. From this time the gain is only about half as rapid, or at the rate of 2 to 4 ounces weekly. At six months, therefore, the average baby weighs from 15 to 16 pounds, or double the normal birth weight of 7½ pounds, and at twelve months he weighs from 20 to 22 pounds, or three times the average birth weight. Fig. [41] gives an idea of how the baby’s weight drops during the first week and the rate of the normal weekly gain afterwards, during the first year.
Fig. 41.—Baby’s weight chart showing the usual loss during the first week and subsequent gain during the first year of life.