Objective: In this study, we aimed to compare the efficacy of low dose bupivacaine vs. bupivacaine plus fentanyl, both administered via PCA, for pain relief during labor. Materials and Methods: A total of 40 healthy pregnant women in the active phase of labor were included and randomly allocated into the two following PCA analgesia groups: 0.125% bupivacaine (Group B) and 0.125% bupivacain + 2 μg/ml fentanyl (Group BF). Hemodynamic parameters were recorded. Fetal heart rate and uterine contractions were monitored. Also recorded were the time of onset of analgesia, pain score, sensory and motor block levels, and adverse effects, as well as amount of solutions required by the pregnant, bolus volumes administered, total solution volume used in PCA, mode of delivery and the result of initial newborns examination. Mothers were asked to rate their level of satisfaction with analgesia after delivery. Results: Onset of analgesia was more rapid in group BF than in group B. Subjects in Group BF had higher sedation, less pain, and less marked motor blockade than group B. The first phase of labor and total time of labor were shorter in Group BF. Volumes of solutions required by the pregnant women and of boluses given during the first phase were also lower in group BF. Satisfaction of pregnant women was higher in group BF. No significant differences were found in other variables between study groups. Conclusion: We conclude that bupivacaine and fentanyl combination provides higher quality of analgesia and better patient satisfaction in labor than bupivacaine alone. INTRODUCTION AND OBJECTIVE Despite temporal and cultural differences between societies in terms of the perception of labor, pain has always been an indispensable element of this event. In the light of the experience gained with epidural anesthesia, it has been possible to achieve higher quality analgesia through reduced concentration of local anesthetics and addition of opioids. Also, methods used for this purpose has changed over time with administration of bolus doses in initial studies, with subsequent widespread use of patient-controlled and continuous analgesia strategies . Similarly, patient-controlled epidural analgesia was used in the current study in order to compare low dose local anesthetic with the combination of opioid and low dose local anesthetic, and to examine their effects on maternal hemodynamics, course of labor, severity of labor pain and maternal satisfaction as well as the effects on newborn. MATERIALS AND METHODS Following ethics committee approval, a total of 40 nulliparous or multiparous pregnant women between 19 and 34 years of age and with an ASA I status were included in this study, after providing written and oral informed consent. Exclusion criteria included cephalopelvic disproportion, preterm labor, intrauterine growth restriction, and participant age less than 18. Fetal heart rate and uterine contractions were monitored with cardiotocography throughout the labor. After initiation of epidural analgesia, all study parameters were recorded every 5 minutes in the first 30 minute period, followed by hourly recording until completion of labor. However, only data obtained during the pre-determined time period (i.e. at baseline, and 15 minutes, 30 minutes, 1 hour, 2 hour after epidural analgesia, and also at the completion of the 1st and 2nd phase of labor). In pregnant women with normal bleeding-clotting time, prior to Central Bringing Excellence in Open Access Bilge et al. (2016) Email: Int J Clin Anesthesiol 4(2): 1054 (2016) 2/4 the placement of an epidural catheter, an intravenous route was accessed and continuous infusion with 500 ml of lactated ringer’s solution was started. An epidural catheter at intervertebral L2-3 or L3-4 space was placed while the patient was in sitting position. Pregnant women were randomly divided into two groups. The first group (Group B) received 0.125% bupivacaine (1.25 mg/ml) and the second group (Group BF) received 0.125% bupivacaine (1.25 mg/ml) + 2 μg/ml fentanyl as the study solution. Analgesia during labor was maintained using PCEA (patient controlled epidural analgesia) using the following variables: basal infusion at a rate of 5 ml/h, 5 ml patient controlled bolus, 10 minute lock-out time. Pain was scored using the Visual Analogue Scale (VAS), where the severity of pain was marked on a 10 cmlong horizontal line with the number “0” on one end and “10” on the other end (0 and 10 corresponding to no pain and intractable pain, respectively). A VAS score of less than or equal to 3 was considered to indicate effective analgesia. Complications such as nausea, vomiting, hypotension, bradycardia, pruritus, chills, quivering, and respiratory depression occurring during the analgesia administration and within the first 24 hours after labor were recorded. Hypotension was defined as a 20% reduction in the blood pressure or a systolic blood pressure below 90 mm Hg, and ephedrine 5 μg/ml i.v. was administered when required. The time to first pain-free uterine contraction after administration of the drug was recorded as the analgesia onset time in both groups. Motor block levels were checked according to the Bromage scale using alcohol swabs with 15 minute intervals in the first half hour, and every half an hour thereafter. The time to complete cervical dilation (10 cm) and the time from complete cervical dilation to delivery were recorded as the 1st and 2nd phase of labor, respectively. In both phases of the labor, the dose requested from the device by the patient, the bolus dose, and the total drug dose were recorded. The type of labor, i.e. normal, assisted (forceps or vacuum), or cesarean section, was also recorded. The newborn assessment was based on APGAR scoring system at 1 and 5 minutes. Patient monitoring was continued until two hours after delivery. The next morning after delivery, at the time of the removal of the epidural catheter, mothers were inquired about the level of satisfaction with the analgesia administered that was scored as weak, moderate, good, and excellent. For statistical assessments Student’s t test, ANOVA-post hoc Dunnett test, Mann Whitney U test, and Wilcoxon signed rank test were used. The data was expressed as mean ± standard deviation. A p value of less than 0.05 was considered as significant.