Normal labor is a process by which a mature fetus, presenting by vertex is expelled through the birth passage followed by placenta and membranes at the end of a pregnancy. The passage through which the baby is expelled during labor include the soft tissues, covering the bony pelvis. The shape of the pelvic canal is irregular with transversely oval inlet, almost circular cavity and anteroposteriorly oval outlet. Anatomical outlet is a linear boundary formed by the lower border of the symphysis pubis, ischiopubic rami, ischial tuberosities, sacrotuberous ligaments and tip of the coccyx. Normally, there should not be any feto-pelvic disproportion at any level for smooth delivery to take place. At the same time, any tumours of the soft structures of the pelvis or bony anomaly may alter the process of labor. Posterior positions are associated with a narrow fore pelvis and anterior placentation. In normal labor with vertex presentation, the head usually enters the pelvic brim with sagittal suture in the transverse pelvic diameter. If the sagittal suture lies close to the symphysis pubis, more of the posterior parietal bone will present and the condition is called posterior asynclitism, commonly found in primigravidae due to good uterine tone and tight abdominal wall. As the contraction fades, the pelvic floor rebounds causing the occiput to glide forward. With each uterine contraction and relaxation forward rotation continue till occiput is brought down behind the symphysis pubis. Important change in the fetal skull is called moulding due to considerable pressure during passage of head along the birth canal. It is the movement of skull bones near frontanelle and sutures. Labor is a crucial period at the end of a pregnancy for both mother and the fetus. Journey through the maternal pelvis is the most hazardous of all journeys.