Incidence of Obstetric Anal Sphincter Injuries After Training to Protect the Perineum

Obstetric anal sphincter injuries (OASISs) are a devastating postpartum complication; reducing rates is paramount to improving quality of care. In Norway, implementation of a perineal protection program decreased the incidence of OASIS by 48%. We sought to assess impact on OASIS rates following a similar program.

This institutional review board-approved, retrospective cohort study was performed in an academic hospital system. The periods of analysis were November 2014 through October 2015 for the preintervention arm and November 2015 through October 2016 for the postintervention arm. From November 2 to 6, 2015, 2 Norwegian experts conducted a didactic and hands-on, on-site workshop focusing on perineal protection. The experts were then present on labor and delivery wards to reinforce perineal protection in live deliveries. Teachings were emphasized at departmental meetings for the remainder of the year. Data were extracted from electronic medical records and manually audited.

The rate of vaginal delivery was similar among both periods (6504 and 6650; P = 0.059). Obstetric anal sphincter injury rates decreased from 211 (3.2%) preintervention to 189 (2.8%) after the workshop. Although this represented 32 fewer injuries, it was not statistically significant (P = 0.179). Obstetric anal sphincter injuries following forceps-assisted deliveries did decline significantly from 103 (28%) to 81 (21%) (P = 0.014). In addition, incidence of fourth-degree lacerations during resident deliveries decreased significantly from 10 (0.6%) to 3 (0.2%) (P = 0.047).

An educational workshop focusing on perineal support was not associated with a significant reduction in overall OASIS rates. Nevertheless, decreased forceps-related OASIS and fourth-degree lacerations rates support positive influence of the intervention.