Malpresentations

1. Big picture

Malpresentation means the fetus presents to the birth canal with something other than the normal well-flexed vertex. It matters because malpresentation increases the risk of:

• Obstructed labour
• Umbilical cord prolapse
• Fetal hypoxia
• Birth trauma
• Uterine rupture
• Emergency caesarean section
• Postpartum haemorrhage

The normal presentation is:

Longitudinal lie
↓
Cephalic presentation
↓
Well-flexed vertex
↓
Occipito-anterior position

Anything outside this pattern should make you ask:

Can this fetus safely pass through the pelvis vaginally?
Is the fetal head flexed or extended?
Is the lie longitudinal or transverse?
Are membranes ruptured?
Is there cord prolapse or fetal distress?
Do we need emergency caesarean section?