USMLE Step 2 CK Lecture Notes 2019: Obstetrics/Gynecology (Kaplan Test Prep)

POSITION

Relationship of a definite presenting fetal part to the maternal bony pelvis. It is
expressed in terms stating whether the orientation part is anterior or posterior,
left or right. The most common position at delivery is occiput anterior.

Figure I-13-6. Landmarks    and Positions

Occiput:    with    a   flexed  head    (cephalic   presentation)

Sacrum: with    a   breech  presentation

Mentum (chin):  with    an  extended    head    (face   presentation)