Systematic Review


Is the rate of cesarean section significantly different among nulliparous women who receive epidural analgesia during early labour (< 4 cm dilation) vs. those who receive non-regional or epidural analgesia > 5 cm?


While studies overwhelmingly agree that the use and/or timing of epidural analgesia during labour in nulliparous women does not appear to affect cesarean section rates, the validity of randomized controlled trials and meta-analyses is severely limited by high crossover and drop-out rates. In contrast, cohort studies undertaken “as treated” analysis with control of confounding factors demonstrate a 2-3 fold increase in cesarean section. In addition, the generalizability of included studies is limited because the majority of these studies occurred in settings where primary, non-elective cesarean section rates were <10%. A randomized controlled trial that could evaluate the impact of epidural on cesarean section would require use of analgesia in the control group that was as effective as epidural to avoid cross over, but that was not in itself associated with cesarean section.