Abnormal Fetal Presentation

Roya Sohaey, MD

DIFFERENTIAL DIAGNOSIS

Common

Less Common

Rare but Important

ESSENTIAL INFORMATION

Key Differential Diagnosis Issues

Normal presentation at term
- Vertex and occiput-anterior
  - Back of head faces pubis
- 43% vertex at 15-22 weeks
- 90% vertex at 31-35 weeks
3-4% of term fetuses are breech
- 87% deliver by cesarean section
- External cephalic version
  - 40% success in nulliparous women
  - 60% success in multiparous women
Etiology of malpresentation
- Idiopathic
- Prematurity
- Placenta previa
- Uterine anomaly
- Abnormal fetal movement

Helpful Clues for Common Diagnoses

Occiput-Posterior
- Vertex + face to pubis
- Vaginal delivery attempted
  - Labor typically longer
Complete Breech
- Buttocks presenting
- Flexed legs (feet down)
Frank Breech
- Buttocks presenting
- Extended legs (feet up)
Footling Breech
- Foot or feet presenting

Helpful Clues for Less Common Diagnoses

Transverse Lie
- Fetus is sideways
  - Head in one flank, bottom in other
- Obligatory cesarean delivery
Incomplete Breech
- Hybrid of complete and frank breech
- One leg extended and one leg flexed

Helpful Clues for Rare Diagnoses

Funic Presentation
- Umbilical cord slips in front of fetus
  - More common with nonvertex presentation
- Cord may prolapse into vagina
- Emergency cesarean delivery

Other Essential Information