Effect of Preemptive Epidural Analgesia in Labor on Cytokine Production

The interrelationship between vaginal labor, cytokine production, and epidural analgesia is unknown. Vaginal delivery is thought to induce a maternal inflammatory response. Though epidural analgesia during labor was found to significantly influence peripartum maternal and newborn interleukin concentrations, these studies did not address at what stage epidural analgesia was performed. Preemptive analgesia has been found to be associated with attenuated proinflammatory cytokines, at least in the postoperative period. Healthy ASA I term parturients (\>37 weeks) being accepted into delivery ward and wanting epidural analgesia will be studied. Parturients will be divided into two groups: * Group I- those who have painless contractions awaiting augmentation of labor. * Group II- parturients with cervical dilatation and painful labor (VAS \>5). Parturients in Group I will be given epidural analgesia immediately upon arrival in the labor ward before onset of painful contractions (VAS\<3). Parturients in Group 2 will be given epidural analgesia as soon as possible. Epidural analgesia protocol will be identical for both groups: graduated doses of bupivicaine 0.1% 15cc and 100 mcg fentanyl followed by patient controlled analgesia at a concentration of bupivicaine 0.1% and fentanyl 2 mcg/cc delivered at 10cc per hour with possible boluses of 5 cc every ten minutes. Maternal serum will be drawn before epidural insertion and 18-24 hours after delivery. Placental blood will be drawn after delivery. These blood sample will be assessed for IL-1Beta, TNF alpha, IL-1ra, IL-2, Il-6, IL-8, IL-10, IL-18. The patient's chart will be prospectively analyzed for demographic information about parturient and complications and progress of labor.