The Placental Stage

The Prospective Mother: A Handbook for Women During Pregnancy
by J. Morris Slemons

(Page 15 of 21)

Although the third stage is chiefly concerned with the separation and the delivery of the after-birth, on which account it is known as the placental period, the description of other no less remarkable events belongs here. Even after the infant is born the umbilical cord extends from its navel to the placenta, just as it has done throughout pregnancy. Among larger mammals separation of the new-born from the mother is brought about in one of two ways; sometimes the activity of the young breaks the navel-string, though more frequently the mother bites it in two.

Both these methods, we are told, have been employed by savages; but at the beginning of civilization it became customary to sever the cord with a cutting tool, and the tie thrown round it represents the first attempt of man to ligate blood-vessels. Ordinarily there is no need for haste in this operation. On the contrary, some delay is often of advantage, since an appreciable quantity of blood that otherwise would remain in the placenta is thus given opportunity to enter the infant's body. According to present ideas, as long as the heart-beat can be felt in the cord it should not be tied.

The sleep induced toward the close of the previous stage lasts for a few minutes, so that most patients are unconscious through the greater part of the brief placental stage. Before the influence of the anesthetic has worn off, the physician has an excellent opportunity to sew up any laceration which may have occurred in the course of delivery. Slight injuries are not uncommon, especially if the confinement be the first, for the most skillful treatment often fails to prevent them. Since superficial tears are never serious if promptly closed, it is not their occurrence, but the failure to recognize them, or to sew them up when they are recognized, that deserves condemnation.

After the birth of the child the womb becomes smaller, its walls grow thicker, and the cavity within is narrowed. This series of changes partly detaches the placenta, but the separation depends chiefly upon the uterine contractions. These contractions also force the after- birth into the vagina, whence it may ultimately be dislodged by the patient if she bears down again. Usually, however, it is preferable to save her further efforts of this kind, and, as a routine, the physician places one hand upon the abdominal wall, grasps the womb, and, during the contraction, makes firm pressure downward. The maneuver expels the after-birth, which consists of the placenta, the membranes, and the umbilical cord. Then the empty womb will form a hard, spherical mass about the size of the child's head, lying just above or to one side of the bladder.

Slight bleeding also occurs during the third stage, and further loss of blood follows the removal of the after-birth. The total loss varies between a half pint and a pint, though larger amounts may be noted occasionally without appreciable effect upon the mother. Naturally, large, robust women can spare much more blood than those who are anemic. And yet pregnancy invariably prepares the mother for a loss of blood that would alarm anyone unfamiliar with obstetrical practice. Often the woman just delivered is not harmed by a hemorrhage that would endanger the life of a healthy man. This may seem paradoxical, but it is not; for the surplus blood, which formerly performed important duties in connection with the nutrition of the fetus, must now be removed to readjust the mother's circulation.

In a very small number of cases an unduly large loss of blood follows the expulsion of the placenta. Fortunately, by treatment which consists usually in spurring Nature to more vigorous action we are well equipped to deal with this emergency. A wonderful mechanism has been provided by Nature to control excessive bleeding after delivery. If the forces upon which this mechanism depends are sluggish, the physician stimulates them. As in the preceding stages, the muscle fibers of the uterus supply the power in question, and because of this role an observant obstetrician once called them, "living ligatures." Certain of these fibers encircle the mouths of the blood- vessels which have been left open through the detachment of the placenta.

When they contract the vessels are squeezed, impeding the escape of blood. The necessity of this action explains the contractions which continue even after the placenta has been expelled, when they are vigorous enough to cause discomfort they are spoken of as "after-pains." After-pains seldom follow the birth of the first child, but they regularly follow later confinements. In any case, such contractions do not persist very long, for tiny clots form within the blood vessels and effectually close them. As soon as the lining of the womb has been restored the clots are absorbed, leaving the organ in much the same condition as before conception took place.