The role of mediolateral episiotomy during operative vaginal delivery.

The role of episiotomy with regard to prevention of anal sphincter injuries (OASIS) is under discussion. The recently published guideline of the WHO "Intrapartum care for a positive childbirth experience" states that the role of episiotomy during operative vaginal deliveries remains to be established. This guideline is based on the evidence coming from randomised clinical trials. However, since the turn of the century large observational studies have pointed out that adequately performed mediolateral episiotomies may play an important role in the prevention of OASIS during operative vaginal deliveries. In this paper we present this evidence and plead for a broader vision on, and use of other evidence than randomised clinical trials solely, the preventive role of mediolateral episiotomy with regard to the occurrence of OASIS.