This is referred to as “lightening.” Lay people might call this “dropping.” (a) In a primigravida, this may occur two weeks before delivery. The fetus head is pushed deep into the pelvis in a sideways position, the face is to the left and the occiput is to the right. The fetus in the vertex position makes seven adaptations or cardinal movements.
The mechanism of labor in the left occiput anterior (LOA) presentation.Ī–Descent. When the presenting part reaches the pelvic bones, it must make adjustments to pass through the pelvis and down the birth canal (see figure 10-6).
As the force of the uterine contractions stimulates effacement and dilatation of the cervix, the fetus moves toward the cervix. This refers to the movements made by the fetus during the first and second stage of labor.