Researchers found higher preterm births, but lower risk of C-section among mothers with OUD than mothers without
Study: Relationship between opioid use disorder during pregnancy, delivery-related outcomes, and healthcare utilization in Michigan Medicaid, 2012-2021 (DOI: 10.1016/j.josat.2025.209720)
Perinatal mothers enrolled in Michigan Medicaid between 2012 and 2021 who had opioid use disorder were more likely to have a premature birth and to use more health care services than mothers without OUD, according to a University of Michigan study.
However, researchers found that only 47% of mothers with opioid use disorder were prescribed medication to treat it.
The study, funded by the Center of Medicare and Medicaid Services through the Michigan Department of Health and Human Services and the National Institutes of Health, is important because perinatal substance use is a critical public health problem in the United States and a primary driver of maternal morbidity and mortality, said Clayton Shuman, associate professor at the U-M School of Nursing.
"Although greater health care utilization is sometimes viewed negatively, our results may suggest that higher use could be a sign that mothers with opioid use disorder are using services important to their overall well-being and recovery trajectory, such as psychotherapy services and substance use disorder treatment," Shuman said.
For the study, researchers wanted to examine delivery-related outcomes and health care use among Michigan Medicaid enrollees ages 15-44 who delivered a live infant between 2012 and 2021. Their study cohort included nearly 219,000 deliveries among 170,000 Medicaid enrollees; of those, 3.3% had an OUD diagnosis during the analytic period.
Preterm births cost families, taxpayers
Shuman said that babies born before 37 weeks gestation are at increased risk for serious health issues that may affect them throughout life, such as chronic respiratory complications, neurological and developmental disabilities, vision problems and even death
"Many babies born premature are admitted to a special care or neonatal intensive care nursery, which can disrupt mother-baby bonding, complicate breastfeeding efforts, and increase a mother's risk for mental health issues like postpartum depression and post-traumatic stress disorder," Shuman said. "Further, preterm birth is associated with higher health care costs to Medicaid and out-of-pocket expenses, which impacts the Medicaid program and taxpayers and adds immense stress to family finances."
Mothers with OUD used more health care
The study also found that people with opioid use disorder had higher rates of health care utilization, particularly for psychotherapy and substance use disorder care and outpatient and emergency care services than those without OUD.
The study could not differentiate between excessive and necessary health care use, but Shuman said mothers with substance use disorders, like OUD, are less likely to access health care services like prenatal and primary care.
"Although we do not know why these services were utilized, these may represent additional opportunities for health care providers to address this population's needs through treatment and referral," he said. "Further, increased rate of psychotherapy and substance use treatment services highlights the use of necessary OUD treatment."
Few get medication for OUD
Shuman said only 47% of the mothers with OUD received medication for opioid use disorder, a low number that Shuman said is a missed opportunity given that these medications work.
"Use of medications like methadone and buprenorphine to treat opioid use disorder is recommended for mothers with OUD," he said. "The rate of medication for OUD in our study suggests opportunities to improve treatment for this population."
Mothers with OUD are primarily urban, white
The majority of the individuals with OUD were white and lived in urban areas, which is inconsistent with national trends. In recent years, the opioid crisis has tended to disproportionately affect white mothers in rural areas across the U.S.
"Our finding that higher rates of OUD were identified among white, urban mothers may be related to better access to detection/diagnosis and care. Other studies using Michigan Medicaid data have observed similar findings," Shuman said. "Mothers living in rural areas represent a smaller proportion of the population partially due to the fact that rural areas have small overall populations; however, more work is needed to improve diagnosis and access to treatment for mothers in these settings."
Lower probability of C-sections
One surprising finding is that people with opioid use disorder had lower probability of cesarean delivery than those without opioid use disorder.
Researchers found that while mothers with OUD had higher C-section rates (38% vs. 31%), their risk was actually lower when considering other factors like health issues and prenatal care.
Shuman said this finding suggests that increased health care engagement, including OUD treatment, may reduce underlying risk factors. Ultimately, the study indicated that other obstetrical comorbidities, rather than the OUD diagnosis itself, were the stronger drivers of C-section risk.
The takeaway for clinicians
"Although there are signs that care and outcomes are improving for this population, clinicians and policymakers must not be complacent as more work is needed--especially in implementing programs and services to prevent OUD and treat those affected," Shuman said. "Despite recent declines in opioid use related to policy efforts and improvements in clinical care, use of other substances during pregnancy must also be addressed, such as cannabis, alcohol, psilocybin, stimulants and tobacco.
Co-authors include: Xiaosong Zhang, Stephanie Hall, Anca Tilea, Sarah Clark, Anna Courant, Kara Zivin of the University of Michigan and Ashlee Vance of the Henry Ford Health System.
