Gynaecology & Obstetrics Rate of cervical dilatation in primi during the active phase of labour is: A 0.5 cm/hr B 1 cm/hr C 1.5 cm/hr D 2 cm/hr. 💡 Explanation Rate of cervical dilatation in primi during the active phase of labour is: ✓ Correct Answer: B. 1 cm/hr