Presentation (obstetrics)

Classification

• cephalic presentation :
• * vertex —the most common and associated with the fewest complications
• * sinciput
• * brow
• * face
• * chin
• breech presentation :
• * complete breech
• * footling breech
• * frank breech
• shoulder presentation:
• *arm
• *shoulder
• *trunk
• compound presentation—when any other part presents along with the fetal head

  Related obstetrical terms

Attitude

• Definition: Relationship of fetal head to spine:
• *flexed,
• *neutral,
• *extended.
• *hyperextended

  Position

• Relationship of presenting part to maternal pelvis based on presentation. The fetus enters the pelvis in the occipito-transverse plane, descent, and flexion and then rotates 90 degrees to the occipitoanterior.
• * Cephalic presentation
• ** Vertex presentation with longitudinal lie:
• ***Left occipitoanterior —the occiput is close to the vagina, facing anteriorly and toward the left. This is the most common position and lie.
• ***Right occipitoanterior —the occiput faces anteriorly and toward the right. Less common than LOA, but not associated with labor complications.
• ***Left occipitoposterior —the occiput faces posteriorly and toward the left.
• ***Right occipitoposterior —the occiput faces posteriorly and toward the right.
• ***Occipitoanterior—the occiput faces anteriorly
• ***Occipitoposterior—the occiput faces posteriorly
• ** Face presentation
• ***Mentum anterior—the fetal chin is in the direction of the maternal pubic symphysis.
• ***Mentum posterior—the fetal chin is in the direction of the maternal sacrum. This presentation is not compatible with vaginal delivery
• *Breech presentation with longitudinal lie:
• **Left sacrum anterior —the buttocks, as against the occiput of the vertex presentation, lie close to the vagina, which lie anteriorly and toward the left.
• **Right sacrum anterior —the buttocks face anteriorly and toward the right.
• **Left sacrum posterior —the buttocks face posteriorly and toward the left.
• **Right sacrum posterior —the buttocks face posteriorly and toward the right.
• **Sacrum anterior—the buttocks face anteriorly.
• **Sacrum posterior —the buttocks face posteriorly.
• * Shoulder presentations with transverse lie are classified into four types, based on the location of the scapula. This presentation needs to be delivered by cesarean section.
• **Left scapula-anterior
• **Right scapula-anterior
• **Left scapula-posterior
• **Right scapula-posterior

  Lie

• Definition: Relationship between the longitudinal axis of fetus and mother:
• *longitudinal
• *oskie
• *oblique
• *transverse
• **back up
• **back down