Comparison of continuous infusion versus midwife administered top-ups of epidural bupivacaine for labour analgesia: effect on second stage of labour and mode of delivery

Using a population-based study we retrospectively compared the effect of continuous versus intermittent top-up epidural analgesia on the outcome of labour at the University Hospital of Wales. We analysed the labour outcome of 410 primigravid deliveries over an 18-month period during a change in delivery suite protocol. Data were retrieved from the Cardiff Births Survey and the sample was analysed in two groups: group 1 ( n=201) received a continuous infusion of 0.1% bupivacaine plus fentanyl 2 μg/mL and group 2 ( n=209) received intermittent top-ups of the same solution. Outcome measures were the number of operative deliveries and the proportion of those deliveries that were due to prolongation of the second stage of labour. There were no significant differences in terms of group characteristics, women undergoing assisted vaginal delivery (group 1: 83 vs. group 2: 70, OR 0.8 CI 0.5–1.2), caesarean section (group 1: 59 vs. group 2: 61, OR 1.0 CI 0.6–1.5), and women with prolonged second stage (group 1: 50 vs. group 2: 47, OR 1.1 CI 0.6–1.8). The presumed reduction in motor blockade associated with intermittent top-up epidural regimes did not affect the outcome of labour.