Episiotomy: the biomechanical impact of multiple small incisions during a normal vaginal delivery

Childbirth-related injuries are one of the main causes of pelvic floor dysfunction. To attempt to avoid serious tears during delivery, an episiotomy can be performed. In this study, we intended to investigate the biomechanical performance of the pelvic floor muscles after performing different episiotomies using a physics-based computational model which includes the pelvic floor muscles and the fetus. Previous biomechanical studies have analysed the mechanical effects of single incisions of different lengths; in this study, we intend to analyse the implications of multiple small incisions, evaluating the reaction forces, the stress on the muscles and the loss of tissue integrity sustained by the pelvic floor. The obtained results predict that an episiotomy delivery reduces the likelihood of macroscopic levator trauma by decreasing the stress on the region of insertion of the rectal area of thelevator ani in thesymphysis pubis . From the mechanical point of view, multiple incisions do not bring benefits compared to larger incisions. However, nothing can be ascertained about the clinical benefit of such an approach.