Percentages of presentations.
(a) Head first is the most common-96 percent.
(b) Breech is the next most common-3.5 percent.
Shoulder or arm is the least common-5 percent.
Specific presentation may be evaluated by several ways.
(a) Abdominal palpation-this is not always accurate.
Vaginal exam--this may give a good indication but not infallible.
Ultrasound--this confirms assumptions made by previous methods.
(d) X-ray--this confirms the presentation, but is used only as a last
resort due to possible harm to the fetus as a result of exposure to radiation.
c. Attitude. This is the degree of flexion of the fetus body parts (body, head,
and extremities) to each other. Flexion is resistance to the descent of the fetus down
the birth canal, which causes the head to flex or bend so that the chin approaches the
Types of attitude (see figure 10-2).
A--Complete flexion. B-- Moderate flexion. C--Poor flexion. D--Hyperextension
Figure 10-2. Types of attitudes.