Addition of clonidine to an epidural mixture of local anaesthetic and morphine improves analgesia and reduces the frequency of motor blockade during epidural analgesia. several side effects are possible mostly somnolence and hypotension. Association of continuous clonidine infusion with low concentrations of levobupivacaïne and sufentanil was not studied during labour. The objective of this study is to compare the effectiveness and the side effects of a PCEA with levobupivacaïne 0,0625 % and sufentanil 0.25 microg.ml-1, without addition of clonidine, and with addition of clonidine at a concentrations of 2 microg.ml-1.

Inclusion Criteria:

• Patients of ASA class I or II
• Variable parity
• Aged of 18 years or more
• With a normal pregnancy
• Cervical dilation between 3 and 8 cm)
• Wishing an epidural analgesia
• Normal childbirth
• Giving their written assent
• Affiliated with a social security system
• Must have had an anaesthesia consultation more than 48 hours before inclusion.

Exclusion Criteria:

• Request of the patient
• Failure of epidural analgesia
• Childbirth in the 90 minutes following the induction of analgesia
• Realization of a Caesarean section