Seven episiotomy incisions are described in the literature, although only midline, mediolateral or lateral episiotomies are commonly used. Recent research has demonstrated variations in both site and direction of the incision, and differences between the angle of incision at the time of crowning of the fetal head and the angle of the scar once the wound has been repaired. We review this evidence and suggest that this variation may undermine the reliability of much published work. We suggest a standardised definition of each type of episiotomy to establish uniformity going forward, so that future studies are amenable to comparison and meta-analysis.

An incision angle of mediolateral episiotomy of 60° resulted in a low incidence of anal sphincter tearing, anal incontinence and perineal pain. A randomized controlled trial is needed to assess the outcome when different angles of episiotomy are used.

The suture angle cannot currently be used to assess the adequacy of the incision angle; moreover, an incision angle of 40 degrees is probably too acute to prevent potential sphincter damage.

No abstract

In a biomechanical assessment with simulation of vaginal delivery, exact placement of fingertips on the perineal skin, together with their co-ordinated movement, plays an important role in the extent of reduction of perineal tension.