The outcome "Regional and general anaesthesia" is presented in a subgroup analysis. Pudendal, epidural and general anaesthesia, are first analysed independently and a subtotal typical relative risk is calculated for each one. At the end, a total typical relative risk is calculated for the three outcomes together and it is the figure shown in the summary of analysis. This last procedure is not appropriate for these outcomes since it considers the same studies and the same women three times, resulting in a biased analysis and an artificial sample size. Thus, readers do not have to consider the total estimate in this outcome and should only consider the subtotals of the different subgroups.