Epidural ropivacaine versus bupivacaine for labor: a meta-analysis.

UNLABELLED: Numerous studies have compared ropivacaine with bupivacaine for labor analgesia. Early studies suggested that obstetrical and some neonatal outcomes were improved when ropivacaine was used. We systematically reviewed and combined the results of the randomized controlled trials that compared ropivacaine with bupivacaine to determine whether or not there was a difference in these outcomes. We searched electronic databases and journals for randomized controlled trials composed of laboring parturients. The primary outcome was the incidence of spontaneous vaginal delivery. We examined other obstetrical, neonatal, and analgesic outcomes. Where possible, these were combined by using metaanalytic techniques and random effects modeling. We found 23 randomized controlled trials composed of 1043 patients receiving ropivacaine and 1031 receiving bupivacaine. There was no significant difference in the incidence of spontaneous vaginal delivery (odds ratio, 1.17; 95% confidence interval, 0.98-1.41; P = 0.12) or any of the other outcomes. Although more studies reported a more frequent incidence of motor block with bupivacaine, the results were heterogeneous and therefore not combined. We conclude that there is no statistically significant difference between the two drugs in the incidence of any obstetrical or neonatal outcome. Further studies using clinically appropriate concentrations of drugs are required to determine whether or not there is a difference in the incidence of motor block. IMPLICATIONS: This metaanalysis of 23 randomized controlled trials shows that both ropivacaine and bupivacaine provide excellent labor analgesia. There was no significant difference between the two drugs in mode of delivery, maternal satisfaction, or neonatal outcomes. Whether or not there is a difference in motor block at clinically relevant doses is unresolved.