Vaginal births are often associated with some form of trauma to the genital tract, which can sometimes be associated with significant short- and long-term problems for the woman. It is especially the third- and fourth-degree tears, that affect the anal sphincter or mucosa, which can cause the most problems. Perineal trauma can occur spontaneously or result from a surgical incision of the perineum, called episiotomy. Different perineal techniques and interventions are being used to slow down the birth, and allow the perineum to stretch slowly to prevent perineal injury. Perineal massage, warm compresses and different perineal management techniques are widely used by midwives and birth attendants. The objective of this review was to assess the effect of perineal techniques during the second stage of labour on the incidence of perineal trauma. We included eight randomised trials (involving 11,651 women) conducted in hospital settings in six countries. The participants in the included studies were women with no medical complications who were expecting a vaginal birth. We conclude that there is sufficient evidence to support the use of warm compresses to prevent perineal tears. The procedure has been shown to be acceptable to both women and midwives. From the meta-analyses we found significant effect of the use of warm compresses compared with hands off or no warm compress on the incidence of third- and fourth-degree tears. We also found a reduction in third- and fourth-degree tears with massage of the perineum versus hands off; and of ‘hands off’ the perineum versus ‘hands on’ to reduce the rate of episiotomy. The studies in our systematic review have considerable clinical variation and the terms ‘hands on’, ‘hands off’, ‘standard care’ and ‘perineal support’ can mean different things and are not always defined sufficiently. The methodological quality of the included studied also varied.
The question of how to prevent the tears is complicated and involves many other factors in addition to the perineal techniques that are evaluated here, e.g. birth position, women’s tissue, speed of birth. More research is necessary in this field, to evaluate perineal techniques and also to answer the questions of determinants of perineal trauma.