Passage of a show or spontaneous rupture of membranes may be associated with the onset of labour but is not required in its definition.

The material describes show and spontaneous rupture of membranes as possible accompanying signs. Labour itself is diagnosed by regular, rhythmic contractions causing progressive cervical change. Therefore, neither show nor membrane rupture is essential to the definition. **Key takeaway:** Cervical progress with regular contractions is central; show and rupture may accompany it.\n\n**Glossary:** **Show**: passage of blood-stained mucus from the cervix; **membranes**: the fetal sac surrounding the amniotic fluid.