Examination of the patient is important before the onset of labor to assess the fetal position with respect to the pelvis. This can be done clinically by abdominal palpation, vaginal examination, or fetal heart auscultation. Sonography can also be used to confirm fetal position in certain cases.
ABDOMINAL INSPECTION AND PALPATION (LEOPOLD'S MANEUVERS)
The position of the baby in utero is determined by inspecting and palpating the mother's abdomen, with these questions in mind:
Is the lie longitudinal, transverse, or oblique?
What presents at or in the pelvic inlet?
Where is the back?
Where are the small parts?
What is in the uterine fundus?
On which side is the cephalic prominence?
Has engagement taken place?
How high in the abdomen is the uterine fundus?
How big is the baby?
The patient lies on her back with the abdomen uncovered (Fig. 9-1). To help relax the abdominal wall muscles, the shoulders are raised a little and the knees are drawn up slightly. If the patient is in labor, the examination is carried out between contractions.
Position of patient for abdominal palpation.
First Maneuver: What Is the Presenting Part?
The examiner stands at the patient's side and grasps the lower uterine segment between the thumb and fingers of one hand to feel the presenting part (Fig. 9-2A). The other hand may be placed on the fundus to steady the uterus. This maneuver should be performed first. Since the head is the part of the fetus that can be identified with the most certainty and since it is at or in the pelvis in 90 percent of cases, the logical thing to do first is to look for the head in its most frequent location. Once it has been established that the head is at the inlet, two important facts are known: (1) that the lie is longitudinal and (2) that the presentation is cephalic. An attempt is made to move the head from side to side to see whether it is outside the pelvis and free (floating) or in the pelvis and fixed (engaged). In contrast to the breech position, the head is harder, smoother, more globular, and easier to move. A groove representing the neck may be felt between the head and the shoulders. The head can be moved laterally without an accompanying movement of the body. When the head is in the fundus and when there is sufficient amniotic fluid, the head can be ballotted.
When a floating rubber ball is forced under water, it returns to the surface as soon as it is released; so the fetal head can be pushed posteriorly in the amniotic fluid, but as soon as the pressure on it is relaxed, ...