Decline in Episiotomy Reduces Resident Exposure to Repair of OASIS

Objectives: The goal of this study is to identify resident exposure and involvement in repair of third and fourth degree perineal lacerations sustained at the time of vaginal delivery over the course of 16 yeas. As national trends in routine episiotomy have declined, most notably following ACOG recommendation against routine episiotomy in 2006, we wanted to investigate whether this change yields fewer obstetric anal sphincter injuries, thus lessening opportunity for resident involvement in repair of higher order perineal lacerations during the course of OBGYN training.

Methods: This is a retrospective cohort study at a large tertiary academic hospital identifying patients who sustained a third or fourth degree laceration after spontaneous, vacuum-assisted or forceps-assisted vaginal delivery between the years of 2007-2022. Records from the electronic medical record were queried to identify women who either had an episiotomy and/or sustained any third or fourth degree laceration at the time of delivery using ICD-9 and ICD-10 codes. Rates of cesarean delivery and operative vaginal delivery were also explored. The years investigated were separated into four year time intervals in effort to represent the duration of OBGYN residency.

Results: The percentage of third and fourth degree perineal lacerations sustained at the time of vaginal delivery decreased from 4.2% to 3.0%
On average, residents were exposed to fewer third and fourth degree lacerations over time, falling from an average of 45.1 in 2007-2010 to 19.6 in 2019-2022.

At our institution during the study interval, the rate of episiotomy fell from 6.5% to 1.7%.
Episiotomy was associated with 25.4% of third/fourth degree lacerations in the first time interval and 9.2% in the final time interval.
The overall number of third and fourth degree lacerations related to episiotomy that residents were exposed to over the course of their four year residency fell from 11.5 to 1.8.

Despite the decline in third and fourth degree lacerations, the overall rate of operative vaginal delivery decreased from 7.8% to 5.8% and the cesarean rate decreased from 35.4% to 33.1%

Conclusions: Third and fourth degree lacerations have known associated short and long time morbidity for women. Thus, proper technique for OASIS repair is a vital skill that should be mastered by all OBGYN trainees. In this study we found an association between obstetric anal sphincter injury and episiotomy. Thus, with the decline in rates of routine episiotomy, there are fewer third and fourth degree lacerations and residents therefore have less exposure to repair of obstetric anal sphincter injuries, thus putting patients at risk of worse healing and possibly worse long term outcomes.