The transition phase of labour is characterized by the most rapid cervical dilation, typically from 7 cm to 10 cm. This phase marks the end of the first stage of labour and prepares the cervix for the second stage. It is usually the shortest but most intense phase, with strong and frequent uterine contractions facilitating quick cervical change. In contrast, the latent phase has slower dilation and the expulsive phase involves fetal descent, not dilation. The placental phase occurs after delivery. Rapid dilation during the transition phase is critical for timely progression to delivery.

Reference: Cunningham’s Manual of Obstetrics, Kenneth J. Leveno, 26th Edition.