Co-occurring opioid and stimulant use disorder and the relationship to severe maternal morbidity

To evaluate the impact of the use of opioids, stimulants, or both on the rates of various severe maternal morbidity (SMM) events during inpatient delivery-related hospitalizations among patients with substance use disorder (SUD).

We performed a cross-sectional analysis of inpatient pregnancy hospitalizations from the Healthcare Cost and Utilization Project (HCUP) National Inpatient Sample (NIS) from 2016 to 2022. Hospital and core files were linked and cross-referenced for demographic information. International classification of diseases (ICD) 10 codes were used to identify patients with SUD who had an SMM event during a delivery hospitalization. SMM was defined as a composite of individual maternal morbidity diagnoses, as characterized by the centers for disease control (CDC). Survey-weighted multivariable logistic regression models estimated the adjusted odds of SMM among delivery hospitalizations of patients with opioid use disorder (OUD), stimulant use disorder (StUD), or co-occurring OUD and StUD, using delivery hospitalizations of patients without any SUD as the reference group. Models adjusted for maternal age, race/ethnicity, primary insurance payer, household income quartile, hospital region, hospital location and teaching status, hospital bed size, cohort year, and Elixhauser comorbidity score. Prevalence of composite SMM and individual SMM events was compared across exposure groups using Rao-Scott chi-square tests.

Of the 4,804,219 delivery-related inpatient pregnancy hospitalizations over the study period, 45,671 admissions were identified as having SUD with either opioids (28,464), stimulants (13,920), or both (3287). There was an increasing trend of StUD from 2016 to 2021 (p < 0.0001). Overall rates of SMM between 2016 and 2022 were significantly higher among pregnancy hospitalizations for those with co-occurring SUD (adjusted odds ratio [aOR], 5.12; 95% confidence interval [CI], 4.48-5.84), followed by StUD (aOR, 3.84; 95% CI, 3.578-4.13) and OUD (aOR, 2.23; 95% CI, 2.09-2.38), compared with delivery hospitalizations of patients without any SUD. There were significant differences between the rates of individual SMM events between those with StUD, OUD, and those with co-occurring use disorder at all time points.

Pregnant people with co-occurring OUD and StUD are at a significantly increased risk of SMM overall, as well as risk of certain individual SMM events as compared to those with OUD or StUD alone.