Perinatal outcomes in individuals with co-occurring anxiety and/or depression and substance use in pregnancy.

BACKGROUND: The prevalence of substance use and mental health disorders is rising in pregnancy, however there is a paucity of evidence of how co-occurring diagnoses affect maternal and neonatal wellbeing. OBJECTIVE: To examine the association between co-occurring anxiety and/or depression and substance use in pregnancy and adverse perinatal outcomes. STUDY DESIGN: This is a retrospective cohort study analyzing linked vital statistics and hospital discharge data from all births in California between 2008 and 2020. Individuals with anxiety/depression and co-occurring substance use disorders were identified using International Classification of Disease (ICD-9-CM and ICD-10-CM) codes. Statistical analysis was performed using Chi-square tests and multivariable Poisson regression models. RESULTS: A total of 139,563 pregnant individuals with anxiety/depression met inclusion criteria, 12,235 (8.8%) had co-occurring substance use. Individuals with anxiety/depression and stimulant or polysubstance use had increased risk of adverse maternal outcomes compared to those with anxiety/depression alone. Individuals with anxiety/depression and stimulant use had the highest risk of hypertensive disorder (aRR=1.65, 99.5% CI 1.31, 2.07) and severe maternal morbidity (aRR=2.06, 99.5% CI 1.38, 3.09). Co-occurring anxiety/depression and substance use also negatively impacted neonatal outcomes. Anxiety/depression and opioid use was associated with an increased risk of preterm birth <37 weeks (aRR=1.76, 99.5% CI 1.40, 2.20), neonatal intensive care unit admission (aRR=3.65, 99.5% CI 3.23, 4.12), and respiratory distress syndrome (aRR=2.39, 99.5% CI 1.83, 3.12). The risk of having a small for gestational age neonate was increased for co-occurring diagnoses across all types of substance use with the exception of alcohol use. CONCLUSION: Substance use during pregnancy, especially stimulant or polysubstance use, in individuals with anxiety/depression compared to those with anxiety/depression alone was associated with worse maternal and neonatal outcomes that varied depending on the type of substance. These findings highlight areas to target counseling and intervention to mitigate perinatal morbidity.