 Perineal pain after childbirth occurs in the majority of women with or without episiotomy. Perineal pain can become source of chronic pain in 9-12 of the cases. Neostigmine a cholinesterase inhibitor at a dose of 500μg combined with Sufentanil or Ropivacaine local anaesthetic is an analgesic. The goal of this study is to examine the effect of the use of epidural Neostigmine for perineal analgesia at the end of the labor on acute pain and on the development of chronic pain post partum. 