This prospective, double blinded study investigates spinal anesthesia with or without clonidine added to bupivacaine in newborns. This study is based on duration measurement of spinal anesthesia and cardio respiratory recording during 24h for apnea detection.

Ex premies and term neonates are two subgroups investigated separately. The overall objective is to validate lengthening of spinal anesthesia in newborns in order to avoid "rescue" general anesthesia that occur in 20-40 % of patients with plain bupivacaine.

Inclusion Criteria:

• Newborns less than 60 weeks old post-conceptional, former premature or not
• Newborns requiring inguinal hernia or lower limbs surgery,
• infants needing no more critical care assistance
• Informed consent of parents

Exclusion Criteria:

• Spinal malformation,
• Coagulopathy,
• critical hemodynamics,
• uncontrolled neurologic or metabolic pathology.
• infection at injection point.