Gynaecology & Obstetrics During the active phase of labour, the minimum effective dilatation of the cervix in primigravida should be at the rate of: A 0.5 cm/hour B 1 cm/hour C 1.5 cm/hour D 2 cm/hour 💡 Explanation During the active phase of labour, the minimum effective dilatation of the cervix in primigravida should be at the rate of: ✓ Correct Answer: B. 1 cm/hour