Racial and Ethnic Disparities Among Pregnancies with Substance Use Disorder: Impact on Perinatal Outcomes.

To examine racial/ethnic disparities in severe maternal morbidity (SMM) and adverse pregnancy outcomes (APOs) among pregnant patients with substance use disorder (SUD) compared to individuals without SUD. We conducted a cross-sectional analysis of inpatient hospitalizations of pregnant people from the Healthcare Cost and Utilization Project (HCUP) National Inpatient Sample (NIS) from 2016 to 2019. ICD-10 codes were used to identify the frequency of SMM and/or APO between those with and without SUD by race/ethnicity. Multilevel logistic regression analyses were performed to identify the effect of race/ethnicity as an independent predictor and as an effect modifier of SMM and APO in patients with SUD. From 2,508,259 hospitalizations, SUD was identified in 6.7% admissions with the highest rate in White patients (8.2%) followed by Black (7.7%) and Hispanic (2.2%) patients. Rate of SMM and APO were increased in patients with SUD in all racial/ethnic groups compared to those without SUD, increasing by 1% and 10%, respectively. Among all patients, Black race was an independent predictor of SMM (adjusted odds ratio [aOR] 2.09; 95% confidence interval [CI]: 2.05-2.13) and APO (aOR 1.58; 95% CI: 1.56-1.59). Hispanic ethnicity was also an independent risk factor for predicting SMM (aOR 1.40; 95% CI: 1.37-1.43). Among Hispanic patients, SUD was associated with an ∼90% increased likelihood of SMM and APO. Although higher rates of SMM and APO are seen among hospitalizations of pregnant people with SUD, racial/ethnic disparities also exist among this population. This warrants further attention and presents an opportunity for intervention and for addressing the root causes of racial and ethnic disparities.