Normal labour: defined as regular painful uterine contractions which becomes progressively stronger and more frequent accompanied by the effacement and progressive dilatation of the cervix and the descent of the presenting part of the fetus. The labor is divided into 3 stages. The mechanism of labour is explained by the change in the position and the attitude of the fetus, as the fetus initiates its way through the pelvis (birth canal). Mechanism includes: 1) Engagement 2) Descent 3) Flexion 4) Internal rotation 5) Extension 6) Restitution 7) External rotation