Methods
Criteria for considering studies for this review
Types of studies
Randomised controlled trials (RCTs) only. (We will not include results from quasi RCTs in the analyses but we may discuss them in the text if little other evidence is available.)
Types of participants
Women in labour. (This will include women in high-risk groups, e.g. preterm labour or following induction of labour. We will use subgroup analysis to look for any possible differences in the effect of interventions in these groups.)