vertex presentation

In the vertex presentation the head is flexed and the occiput leads the way.

A malpresentation is any other presentation than a vertex presentation (with the top of the head first).

Normal labor results in a birth between 37 and 42 weeks gestation and the fetus is delivered from a vertex presentation.

Vertex presentation with longitudinal lie:

In the vertex presentation the occiput typically is anterior and thus in an optimal position to negotiate the pelvic curve by extending the head.

The vertex presentations are further classified according the position of the occiput, it being right, left, or transverse, and anterior or posterior:

Shoulder presentation is a malpresentation that is not to be confused with shoulder dystocia, a complication during the birth of a baby in a vertex presentation.

Two-thirds of all vertex presentations are LOA, possibly because of the asymmetry created by the descending colon that is on the left side of the pelvis.

A vertex presentation is the ideal situation for a vaginal birth, however, occiput posterior positions tend to proceed more slowly, often requiring an intervention in the form of forceps, vacuum extraction, or Cesarean section.

A cephalic presentation is a situation at childbirth where the fetus is in a longitudinal lie and the head enters the pelvis first; the most common form of cephalic presentation is the vertex presentation where the occiput is the leading part (the part that first enters the birth canal).