Association of Race and Ethnicity as Risk Factors for OASIs: A Systematic Review

Understanding how race and ethnicity are contextualized as risk factors for obstetric anal sphincter injuries (OASIs) can improve efforts to address maternal health disparities.

Our primary aim was to conduct a systematic review and meta-analysis to examine the association between race/ethnicity and OASI incidence. The secondary aim was to critique how included studies contextualized race/ethnicity as risk factors for OASIs.

This systematic review analyzed observational studies reporting OASI incidence by race and ethnicity. The primary outcome was the overall incidence of OASIs, with odds ratios (OR) calculated using a random effects model. We quantified the racial representation in the included studies using a representation quotient (RQ) analysis and applied the Obstetrics & Gynecology's equity rubric for structured critique.

Out of 3,896 studies, 12 were included. The overall OASI incidence was 4.44% (95% CI, 2.69-6.60%), with Asian American and Pacific Islander (AAPI) individuals having the highest incidence at 5.69% (95% CI, 4.04-7.59%). AAPI individuals had higher odds of OASIs compared with White individuals (OR, 1.61; 95% CI, 1.12-2.31). Two studies provided disaggregated AAPI data by ethnicity. Native American (RQ 0), Black (RQ 0.15), and Hispanic (RQ 0.20) individuals were underrepresented. Among studies that identified racial disparities, 33% attributed findings to systemic factors, 45% did not address disparities, and 22% suggested biological differences without substantiated evidence.

AAPI individuals had 61% higher odds of experiencing OASIs than White individuals. However, most studies aggregated AAPI data, failed to represent the U.S. population, and overlooked system-level factors contributing to the racial disparity in OASI incidence.