gynecology and obstetrics
Fetal Presentation, Position, and Lie (Including Breech Presentation)
Occiput posterior position
The most common abnormal position is occiput posterior. The fetal neck is usually somewhat deflexed; thus, a larger diameter of the head must pass through the pelvis. Progress may arrest in the second phase of labor. Operative Vaginal Delivery or Toward the end of pregnancy, the fetus moves into position for delivery. Normally, the presentation is vertex (head first), and the position is occiput anterior (facing toward the pregnant patient's spine) with the face and body angled to one side and the neck flexed. Abnormal presentations include face, brow, breech, and shoulder. Occiput posterior position (facing toward the pregnant patient's pubic bone) is less common than occiput anterior position. 