11RC2 Neurophysiology of labour pain

Pain arising from the first stage of labour is carried through afferents which course through the paracervical plexus and hypogastric nerve, co-mingle with sympathetic efferents along the pararvertebral sympathetic chain and enter the spinal cord at the T10 to L1 dermatomes. Near the end of the first stage and during the remaining phases of labour there is also input from somatic efferents in the pudendal nerve which innervate the vaginal surface of the cervix, the vagina, and the perineum. As such, analgesia can be accomplished during the first stage of labour by paracervical, paravertebral, or lumbar epidural administration of local anaesthetics.