position changes in fetus

External rotation (restitution) :

the sagittal suture moves to a transverse diameter and the shoulders align in the anteroposterior diameter. The trunk navigates through the pelvis.

Expulsion:

The shoulders and remainder of the body are delivered

Descent:

Movement of the fetus through the birth canal during the first and second stages of labor

Flexion:

When the chin of the fetus moves toward the fetal chest ; occurs when the descending head meets resistance from the maternal tissues

Extension:

facilitated by the resistance of the pelvic floor that causes the presenting part to pivot beneath the pubic symphysis and the head to be delivered

Engagement:

when the greatest diameter of the fetal head passes through the pelvic inlet; can occur late in pregnancy or early in labor

Internal rotation:

when the rotation of the fetal head aligns the long axis of the fetal head with the long axis of the maternal pelvis