Tehran University of Medical Sciences Archives of Anesthesiology and Critical Care 2423-5849 0 0 2026 06 27 1550 1550 Bahareh Mosleh Department of Obstetrics and Gynecology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Maryam Khooshide Department of Obstetrics and Gynecology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Ali Shahriari Department of Anesthesiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Masoumeh Nataj Majd Department of Anesthesiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 2025 12 29 2026 02 22 Background: Epidural is a type of regional anesthesia performed by injecting a local anesthetic agent. In this type of anesthesia, by using a catheter in the epidural space, the anesthetic drug can be re-injected if necessary. For this reason, this study was conducted with the aim of determining and investigating the risk factors for epidural analgesia failure (FEA) and its outcomes in the normal labor process of pregnant women referring to Arash Hospital. Methods: This prospective cohort study evaluated 160 mothers requesting epidural to identify the risk factors for failed epidural analgesia (FEA), where FEA was defined based on the VAS score half an hour after the initial dose. Following thorough pre-anesthesia tests, standard doses were injected using the Loss of Resistance technique, and labor progression and pain (VAS) were monitored periodically. Analyses focused on comparing demographic, technical (physician skill), and obstetric outcome variables between the successful and unsuccessful groups at a significance level of P < 0.05. Results: A statistically significant difference was observed in the variables of effacement, the length of the first and second stages of labor, and the one-minute Apgar score (P < 0.05) between the successful and unsuccessful groups, indicating that in the unsuccessful group, effacement was less, and the labor stages were longer. Moreover, the unsuccessful group exhibited a greater prevalence of Apgar scores below 7 at the first minute, and a higher incidence of fetal heart rate deceleration was also noted in this group (P = 0.01). However, the mean dilation, mode of delivery, satisfaction scores, and five-minute Apgar scores showed no statistically significant difference. These results emphasize the importance of accurate assessment of variables related to labor progression and fetal status in determining the success of the procedure. Conclusion: Overall, the results showed significant differences between the successful and unsuccessful groups in the mean effacement, the length of the labor stages, and the one-minute Apgar score, while other variables, such as dilation, mode of delivery, satisfaction, and the five-minute Apgar score, did not show a statistically significant difference. These results show how the success of labor affects the stages of labor and the baby's health in the first few minutes after birth. https://aacc.tums.ac.ir/index.php/aacc/article/view/1550