Effects of combined spinal–epidural analgesia on first stage of labor: a cohort study

Background: Neuraxial anesthesia is considered as the gold standard in the control labor of pain. Its variants are epidural analgesia and combined spinal–epidural analgesia. Few studies, as yet, have investigated the duration of labor as a primary outcome. Some authors have suggested that combined spinal–epidural analgesia may reduce labor duration but at the moment the benefit of shortening labor is uncertain. The main aim of this study was to compare combined spinal–epidural with epidural analgesia in terms of their effect on duration of stage I labor, maternal, and neonatal outcomes. Methods: A prospective cohort study was conducted. Parturients who requested analgesia at cervical dilatation <6 cm were included. Analgesia was either epidural with low concentration levobupivacaine or combined spinal epidural with subarachnoid sufentanil. The primary outcome was the length of stage I labor. Onset and quality of analgesia, mode of delivery, effects on uterine activity and use of oxytocin, fetal heart rate abnormalities and uterine hyperkinesia, maternal, and neonatal complications were also considered. Results: We enrolled 400 patients: 176 in the combined spinal–epidural group and 224 in the epidural group. Patients in the two treatment groups were similar with regard to demographic characteristics, parity, and incidence of obstetric comorbidities, labor induction, oxytocin infusion, Bishop score, and Visual Analogue Score (VAS) at analgesia request. Duration of stage I labor did not differ, at 195 (120–300) minutes for both the groups (p =.7). Combined spinal–epidural was associated with less reduction in uterine contractility after initial administration: 15.34 versus 39.73%, (p <.001) and with delayed need for oxytocin, at dilations of 7 ± 2.5 cm versus 6. ± 2.7, (p =.002). Onset of analgesia was quicker for combined spinal–epidural analgesia: 31 versus 20%, with VAS <4 after 5 minutes, (p <.001); and lower VAS scores after initial analgesia administration. No differences were found in the other outcomes. Conclusions: Combined spinal–epidural with subarachnoid sufentanil may not reduce the duration of stage I labor, but in our study it appeared to affect uterine contractility less. It also had a more rapid onset and was more effective, without any concomitant increase in maternal or neonatal complications.