Manual protection of the perineum reduces the risk of obstetric anal sphincter ruptures.

INTRODUCTION During vaginal delivery, the risk of obstetric anal sphincter injuries (OASIS) is well-known. Despite sufficient repair, 30-50% of women will experience anal incontinence. Recent studies from Norway have shown a reduction in the incidence of OASIS when the perineum is supported manually. In Denmark, the frequency of OASIS is the highest in Scandinavia and it is increasing. The aim of this study was to reduce the incidence of OASIS through an interventional programme. METHODS We conducted a study inspired by the Norwegian intervention. Our focus was on four points: 1) good communication between the delivering woman and the birth assistant, 2) visualisation of the perineum in the last stages of delivery, 3) support of the perineum during the final minutes of pushing and 4) episiotomy only on indication. A total of 768 primiparous and 1,175 multiparous women were enrolled in this quality improvement cohort study. Data were analysed for association with the occurrence of OASIS. RESULTS The proportions of parturients with anal sphincter ruptures decreased significantly during the first year of the study from 4.4% to 1.7% (p < 0.001). The decrease was more pronounced for primiparous women: from 7.2% to 2.9% (p = 0.006). A similar decrease was observed for instrumental deliveries although this was not significant for primiparous women, probably due to the size of the study population. Episiotomies increased significantly from 4.4% to 7.1% for all deliveries. CONCLUSION After the first year of intervention, our results demonstrate that manual protection of the perineum reduces the overall risk of OASIS significantly. FUNDING not relevant. TRIAL REGISTRATION not relevant.