Intrapartum Interventions and Risk of Perineal Trauma

Abstract

Investigating interventions to reduce perineal trauma faces several challenges including the wide variation in clinical practice and inadequate documentation of the actual interventions adopted by the obstetrician or midwife, like manual perineal protection (MPP), hence limiting the feasibility of properly assessing such interventions retrospectively. Several clinical interventions to reduce risk of perineal trauma at birth have been advocated with varying degrees of efficacy. Antenatal perineal massage, performed by the pregnant woman herself, reduces the need of episiotomy during delivery, but has no effect on spontaneous lacerations on the perineum. Selective use of non-midline episiotomy is associated with a decreased prevalence of OASIS, especially in operative and first vaginal deliveries. Perineal warm compresses during crowning/second stage of labour reduced perineal trauma in general, however the effect on risk of OASIS was non-significant. MPP has been shown to be an effective intervention in reducing the risk of OASIS in several large non-randomised studies. It is important to recognise that these methods will probably have no real impact on incidence of perineal trauma when applied on ad hoc bases. However, the introduction of a standardised and structured management protocol at the time of birth that is uniformly adopted by the entire multiprofessional maternity staff has been shown to significantly reduce the occurrence of OASIS. Indeed, combining MPP with slowing the expulsion of the baby’s head (using two hands) and simultaneously coaching the mother not to push has reduced the incidence of OASIS by 50–70 % in large population based observational studies.