Normal labour, as defined in the material, is diagnosed prospectively as soon as contractions begin.

**Normal labour** is a retrospective diagnosis because its defining features include the eventual course and outcome: spontaneous onset at term, singleton vertex pregnancy, no operative intervention, and delivery of a well child and placenta. The outcome cannot be known at the start. **Key takeaway:** Normality is confirmed from the completed course, not predicted from the first contraction.\n\n**Glossary:** **Retrospective diagnosis**: a diagnosis confirmed after the relevant events have occurred.