The nerve supply to the pelvis is autonomic. Sympathetic nerves from the inferior hypogastric plexus (T10–L1) supply the uterus and cervix. Labour pains are therefore referred to areas of skin supplied by these nerves, e.g. lumbo-sacral region, lower abdomen and loins.
The pudendal nerve (S2,3,4) suplies the vagina and pelvic outlet. There is also a minor supply from the genito-femoral nerve (L1,2) and the perineal branch of the posterior femoral nerve (L2,3,4).