Comparison of obstetric anal sphincter injuries in nulliparous women before and after introduction of the EPISCISSORS-60(®) at two hospitals in the United Kingdom

To assess whether the introduction of episiotomy scissors specially designed to achieve a cutting angle of 60°, EPISCISSORS-60(®), in two hospitals in the UK would result in a reduction in obstetric anal sphincter injuries (OASIS) in nulliparous women. A structured training program for all doctors and midwives provided a theoretical framework around OASIS including risk factors and the role of episiotomies and a practical hands-on training element to use EPISCISSORS-60(®) correctly and to measure perineal body length and post-suturing angles. Data for perineal body length, post-suturing angles, user feedback, episiotomy use, and incidence of OASIS were collected through specifically designed forms and the general hospital data collection system. Data were available for 838 nulliparous vaginal deliveries. Mean perineal body length was 37 mm in spontaneous vaginal delivery group (standard deviation [SD] =8.3, 95% confidence interval [CI] =34-39) and 38 mm in the operative vaginal delivery group (SD=8, 95% CI=35-40). Post-suturing episiotomy angles were 53° (SD=6.5, 95% CI=50.7-55.8) in spontaneous vaginal deliveries and 52° (SD=9.6, 95% CI=49-54) in operative vaginal deliveries. EPISCISSORS-60(®) were rated as "good" to "very good" by 84% of users. There was a 47% increase in the number of episiotomies in nulliparous spontaneous vaginal deliveries at Poole (P=0.007) and a 16.5% increase in the number of episiotomies in nulliparous operative vaginal deliveries in Hinchingbrooke (P=0.003). There was an overall 11% increase in episiotomy numbers in nulliparous vaginal deliveries (P=0.08). There was a statistically significant OASIS reduction of 84% in nulliparous spontaneous vaginal deliveries in women who received an episiotomy (P=0.003). Initial results after introduction of EPISCISSORS-60(®) show that the majority of health care professionals achieve post-suturing episiotomy angles between 40° and 60°. The results also show a significant increase in the use of episiotomies in the delivery of nulliparous women. There has been a statistically significant reduction in OASIS in nulliparous spontaneous vaginal deliveries.