Perinatal outcome of vaginal delivery with epidural analgesia initiated at the early or late phase of labor period: A retrospective cohort study in the Japanese population

AIM: We compared the perinatal outcomes of vaginal delivery with epidural analgesia initiated at the early versus late phase in a Japanese population. METHODS: Women enrolled in this retrospective cohort study received intrapartum analgesia via combined spinal epidural analgesia after labor onset between May 2010 and August 2015. We compared the perinatal outcomes between two different timings of epidural analgesia: at the early phase (≤3 cm cervical dilatation) and the late phase (≥4 cm) or at the new definition-based early phase (≤5 cm) and late phase (≥6 cm). RESULTS: One hundred twenty-eight singleton pregnant women were eligible. In nulliparous women, there was no marked difference in perinatal outcomes between the early and late phase except for in the first-stage labor period (13.7 h vs 10.1 h, P = 0.016). In multiparous women, there was no marked difference in perinatal outcomes between the early and late phase except for a higher proportion of Apgar score ≤7 at 1 min in the early phase (20.0% vs 0.0%, P = 0.033). In nulliparous women, the first-stage labor period in the new early phase was significantly longer than in the new late phase (13.3 h vs 6.9 h, P = 0.035). Other variables for nulliparous women and all for multiparous women were not different between the new early and late phases. CONCLUSION: Most perinatal outcomes between the early and late phases of initiated epidural analgesia were not markedly different in our Japanese population, even when using a new definition of labor phase.