Descent: measured in cm in relation to the ischial spine “station”.
Engagement: presenting part enters true pelvis.
Flexion: neck flexes, causing chin to rest on sternum, so narrowest part of head enters the passageway.
Internal rotation: head rotates so the occiput is next to mother’s symphysis pubis.
Extension: fetus head moves under symphysis pubis & neck extends as head leaves passageway.
External rotation and restitution: fetus head rotate back to normal alignment with shoulders after it has emerged & the shoulders rotate to move beneath symphysis pubis
Expulsion: anterior shoulder leaves passageway; then the head is gently raised as the posterior shoulder leaves the passageway. The rest of the body quickly follows.