Eighty-five per cent of women sustain perineal trauma during vaginal birth. This may occur spontaneously or intentionally when a surgical incision (episiotomy) is made. The overall risk of obstetric anal sphincter injuries (OASIs) is approximately 2% of all vaginal deliveries. The morbidity associated with perineal trauma depends on the extent of injury, the suturing technique and materials, and the skill of the person performing the procedure. Therefore, it is important that focused and intensive training is available and that practitioners ensure that procedures, such as perineal repair, are evidence-based in order to provide care that is effective, appropriate and cost-efficient. In the UK, between 2000 and 2012, the OASIs rate in England tripled from 1.8% to 5.9%, suggesting that preventive measures need to be put in place. In this chapter, we highlight safe obstetric practice and preventative strategies based on the best available evidence to minimise perineal and anal sphincter trauma.

Consequences of obstetric anal sphincter injuries (OASIs) such as anal incontinence can lead to long-term physical and psychological sequelae. As OASIs occur more frequently in nulliparous women, women will probably present in a subsequent pregnancy. A subsequent delivery can increase the risk of developing or deteriorating anal incontinence symptoms. Therefore, counselling and mode of delivery recommendations should occur in the antenatal period to allow women to make an informed choice about their subsequent delivery. Intrapartum, obstetric practice can be adapted by clinicians, taking into account modifiable risk factors associated with repeat OASIs. However, approaches to prevention of sequelae such as anal incontinence in the long term remains unclear. Conservative options such as pelvic floor muscle training should be encouraged and in cases of intractable symptoms, surgical options are available but these should usually be considered in women who have completed their family.