(953) Influence of race/ethnicity on maternal outcomes among nulliparous patients undergoing operative vaginal delivery

Objective: To evaluate the impact of race/ethnicity on maternal outcomes among nulliparous patients who underwent operative vaginal delivery (OVD).

Study Design: We performed a retrospective cohort study among singleton, non-anomalous, nulliparous OVD in California between 2007 and 2012. Maternal race/ethnicity was categorized as non-Hispanic white, non-Hispanic Black, Hispanic, and Asian. Maternal outcomes included success of OVD, 3rd or 4th degree perineal laceration, endomyometritis, postpartum hemorrhage, and severe maternal morbidity (SMM). Multivariable regressions were utilized to evaluate the association of maternal outcomes by race/ethnicity.

Results: Among 121,596 nulliparous patients who underwent OVD, 30.4% were identified as white, 4.2% as Black, 45.1% as Hispanic, and 20.1% as Asian. Hispanic individuals had the highest rate of unsuccessful OVD (5.1%), while Asian patients (18.9%) had the greatest rate of 3rd or 4th perineal laceration (Table 1). Unadjusted rates of postpartum hemorrhage were highest among Asian (4.2%), Hispanic (3.9%), and white (3.8%) patients, while Black (1.2%) and Hispanic (1.1%) individuals had the greatest prevalence of endomyometritis. Rates of SMM were significantly increased in all non-white populations relative to white individuals (p < 0.001). On multivariable analysis, the odds unsuccessful OVD remained increased in Hispanic individuals (aOR 1.12, 95% CI 1.03-1.20) relative to white patients. The likelihood of 3rd or 4th perineal laceration was increased among Asian individuals and decreased among Black and Hispanic patients compared to the white cohort. Black, Hispanic, and Asian patients had an increased risk of endomyometritis relative to white individuals. Hispanic and Asian groups also had an increased likelihood of postpartum hemorrhage and SMM, while Black individuals had a lower risk of postpartum hemorrhage and a non-significant increased risk of SMM.

Conclusion: Maternal outcomes varied by race/ethnicity in nulliparous individuals undergoing OVD. Further research of structural factors that contribute to these racial differences is needed.