Residents' Exposure to Obstetric Anal Sphincter Injury: A 16-Year Temporal Trend

Exposure to the surgical management of obstetric anal sphincter injuries (OASIS) is limited during obstetrics training.

The objective of this study was to quantify residents' exposure to OASI repair during 4-year obstetrics and gynecology (OBGYN) residency and examine temporal trends over a 16-year period.

This was a retrospective cohort study of residents' exposure to OASIS at a community academic hospital from 2007 to 2022. Individuals with documented OASIS (third- or fourth-degree laceration) by International Classification of Diseases, Ninth and Tenth Revisions, codes during vaginal delivery (VD), spontaneous vaginal delivery (SVD), or operative vaginal delivery (OVD), were included. Delivery rates and OBGYN resident positions were examined. Temporal trends in OASIS were analyzed in 4-year epoch to determine average resident exposure during OBGYN residency.

During the 16-year study period, there were 103,234 deliveries (62% VD, 4% OVD, 34% cesarean delivery). Among VDs, there were 2,344 (3.4%) OASIS with 88.5% classified as third-degree and 11.5% as fourth degree. The OASI rate decreased from 4.2% (2007-2010) to 2.9% (2019-2022), whereas OBGYN residents increased by 49% (67 to 99; P < 0.001). Average resident exposure to OASIS decreased from 11 (2007-2010) to 5 (2019-2022; P = 0.55). Subclassification revealed that residents were exposed to 5 third-degree repairs and less than 1 fourth-degree repair, on average, during 2019-2022.

During 4 years of training, average resident exposure was to 7 OASIS, 6 third degree, and 1 fourth degree. Limited exposure to OASIS during residency may be detrimental, as surgical treatment is a complicated yet essential obstetric procedure that carries significant risk of patient morbidity and potential long-term sequelae. Therefore, reliance on supplementation with simulation may improve surgeon competence in OASI management.