The mnemonic
3 Ps
What each word stands for
- PowerUterine contractions and maternal effort
- PassageBony pelvis and soft tissues
- PassengerFetal size, lie, presentation and position
Why it matters clinically
Structures the search for the cause of slow labour.
Where it stops being reliable
Does not cover the psychological state of the mother, which also affects labour.
Teaching aid, still awaiting independent review. Confirm facts in a standard source.