Many have been suggested but evidence is limited. Induction of labour by any method and use of oxytocin to induce or augment labour (especially if hyperstimulation occurs) have been shown to increase risk.
Some other potential factors include:
- Maternal age > 35 years
- Male fetus
- Multiple pregnancy
- Poly-hydramnios
- Eclampsia
- Uterine rupture
- Cervical trauma
- Placental abruption
- Placenta praevia
