Abnormal position and presentation of the fetus

[Tanya Shivari]

Position refers to whether the fetus is facing rearward (toward the woman’s back—that is, face down when the woman lies on her back) or forward (face up).
Presentation refers to the part of the fetus’s body that leads the way out through the birth canal (called the presenting part). Usually, the head leads the way, but sometimes the buttocks or a shoulder leads the way.
The most common and safest combination consists of the following:

Head first (called vertex or cephalic presentation)
Facing rearward
Face and body angled toward the right or left
Neck bent forward
Chin tucked in
Arms folded across the chest

If the fetus is in a different position or presentation, labor may be more difficult, and delivery through the vagina may not be possible.