The Stage of Dilatation

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

(Page 13 of 21)

For reasons which are sufficiently clear, the womb must remain closed while fetal development is in progress; but under normal conditions, when this development is complete, the mouth of the womb dilates and the infant is expelled. The infant never takes an active part in its birth, although physicians once thought it did and attributed tedious labors to stubbornness on its part. The error has been corrected in medical teaching, but many persons unacquainted with the facts cling to the idea that the infant forces its own way out of the womb.

At the end of pregnancy the mouth of the womb is small, too small, often, to admit an instrument as broad as a lead pencil. It is obvious, therefore, that very radical changes must be wrought before the infant can pass. The door, as it were, must be widely opened. This phenomenon, which we call dilatation of the womb, is brought about by involuntary contractions of the muscle fibers in its wall, every point of which they draw upward. Now, the top of the womb is directly opposite its mouth, consequently the contractions inevitably pull its lips wider and wider apart. Ordinarily another factor is concerned in this mechanism. To understand the whole process we must recall that a fluid surrounds the fetus, and that this fluid is contained within elastic membranes. The uterine contractions compress the fluid, drive the membranes, like a wedge, into the mouth of the womb and spread its lips apart. Thus, to the pulling effect just mentioned, a pushing force is added. After full dilatation has been accomplished and the membranes can serve no further purpose, they rupture; as the midwife puts it, "the bag of waters breaks." The quantity of fluid which escapes will vary. Occasionally, a huge gush will drench the patient's clothing; but more often what is lost at first amounts to only a few teaspoonfuls, though small quantities of fluid often dribble away with subsequent contractions.

Although not the rule, it is by no means unusual for the membrane to rupture at the onset of labor, or at least before the mouth of the womb is fully dilated. Exceptionally, rupture occurs a few days before labor begins; and still longer intervals, though extremely rare, have been recorded. Whenever the membranes rupture prematurely, the pushing force of the uterine contractions becomes less effective, though the pulling force is never impaired. Under these circumstances, which occasion what is called a "dry labor," delivery is apt to proceed slowly, yet that does not follow necessarily, for the part of the fetus which happens to lie over the mouth of the womb may act as efficiently as the unruptured membrane would.

During the first stage, the longest of the three, the patient is comfortable between the contractions and generally interests herself in some diverting occupation. The presence of the physician can be of no assistance then, and patients rarely demand it. Usually, they are satisfied to know he is ready to come when called. It is wrong to deceive patients with various recommendations from which they will vainly expect help during this stage; their welfare is best served when they are left alone. Generally the advice of well-meaning friends will be as harmless as it is futile, yet I must emphasize that during the first stage straining to expel the fetus is ill advised. Such effort will surely be ineffective then and may exhaust the patient; in that event it becomes harmful, for she will be fatigued when she most needs strength.

Since, during the first stage, the progress of delivery is not influenced by what the patient may choose to do, she may follow her own inclinations. The average patient will be restless and will keep on her feet most of the time; alternately she will walk or stand still as one or the other happens to make her more comfortable. As a contraction begins she often seeks support, leaning upon a chair or bending over the foot of the bed, and presses with her hands against the lower part of her back. Patients may sit down or lie down whenever they wish; if so inclined they may even go to sleep.

Most patients take no food during the whole course of labor, but, if nourishment is desired, there is no reason for abstaining from it. They may always drink water as freely as they like, and may also have milk, weak tea or coffee, or broth; but alcoholic beverages should never be taken without the specific consent of the physician. This same caution applies to strong coffee and tea. If desired, crackers or toast and rice or other cereals may be eaten in reasonable quantity. For fear of vomiting a patient will occasionally be told not to partake of any food. This advice is given, not because the symptom is alarming, but to save her needless annoyance. Indeed, vomiting frequently indicates that dilatation is well advanced, and, therefore, may generally be regarded as an encouraging sign. Ordinarily a persistent inclination to have the bowels move has the same significance. On the other hand, a constant desire to empty the bladder is more prominent at the onset of labor than later.

To know the moment which marks the transition from the first to the second stage of labor can be of no benefit to the patient; but for the medical attendant the greatest interest centers about this point. Casual observation sometimes enables the physician to recognize it, for characteristically at the close of the first stage the whole picture changes. In a typical case the membranes will rupture at this instant, expulsive efforts will begin, and, as we have just learned, there may be symptoms referable to pressure. Moreover, a blood-tinged discharge, spoken of as the "show," usually makes its appearance about the same time. Since slight bleeding frequently occurs at the beginning of labor, or a little later, this manifestation, like all others, may not be implicitly trusted to indicate the end of the first stage. Such uncertainty, however, is a matter of no great consequence, for in the absence of all these symptoms the physician may, if necessary, accurately determine the degree of dilatation by an internal examination.