Vaginal Exams in Labor
They are painful, disrupt your laboring and generally require you to get into the most uncomfortable position for laboring in, but are vaginal exams necessary for a safe labor?
General medical theory states that the dilation of the cervix is equivalent to the progress made in labor. According to Freedman's Curve, a woman should dilate 1 cm per hour after she has reached 4 centimeters of dilation. This is, of course, based on the averages for dilation.
The problem is most women are not "average." Dilation does not happen according to a straight line, but rather moves more along a curve. This is normal for a structure with great elasticity under stress.
Building materials are considered brittle if they respond to stress (pressure or a weight load) with a straight line. Brittle materials quickly rupture without warning once their limits are reached. Materials which stretch under strain are said to have a high ductility. These materials will not hold their shape, but will stretch as the load increases like a cervix. Graphically, the stretch is shown as a gentle sloping curve. Like a cervix, these materials will respond with gentle stretching until the load reaches the maximum, at which time the stress on the material will greatly increase and the material will "give".
It is not uncommon for a woman to "be stuck" at 5, 6 or 7 centimeters for a few hours, then to move suddenly through the last 2 or 3 centimeters in only a couple contractions. Knowing this is possible, and common, what value remains of checking the cervical dilation?
For many caregivers, cervical exams are the only way to be sure the woman is laboring effectively. It provides objective information that can be recorded, charted and studied by those who have not been with the woman to give a picture of what the labor has been. Yet, since the information gained is not predictive of progress, the picture seen is not an accurate representation of the labor.