This occurs when the baby is too big for the pelvis or the pelvis is too small for the baby. CPD may be due to faults in the pelvis or faults in the foetus or a combination of both.
- The faults in pelvis may be:
- Contracted pelvis
- Deformed pelvis
- The faults in the foetus may be:
- Too large baby
- Foetal monsters
- Locked twins (rare)
CPD is the most important cause of obstructed labour.
Other causes of obstructed labour are malpresentations or malpositions of the foetus, and soft tissue abnormalities of the genital tract. Obstructed labour is the commonest cause of ruptured uterus and a major cause of maternal mortality. Obstructed labour and ruptured uterus can be prevented by appropriately timed caesarean section.