RÉSUMÉ
OBJECTIVE: To estimate the independent and combined effects of in utero exposures on birth outcomes in a rural population. STUDY DESIGN: The study used population-level data (2020-2022) from a state-wide surveillance tool (Working in Appalachia to identify at-risk infants, Critical congenital heart disease, and Hearing loss) in West Virginia. Outcomes included low birth weight, preterm birth, small for gestational age, and birth weight in grams. Exposure included a composite variable with 8 levels of 3 exposure (opioids, stimulants, and cannabis) categories. Analyses were adjusted for sociodemographic covariates using multiple logistic and linear regression analyses. RESULTS: Of the 34â412 singleton live births, 1 in 8 newborns (12.2%) had in utero exposure(s) to opioids, stimulants, and/or cannabis, 11.5% were preterm, 7.9% had low birthweight, 9.6% were small for gestational age, and mean birth weight was 3249 ± 563.6 g. Preterm birth was associated with stimulant alone exposure (aOR, 1.40; 95% CI, 1.03-1.89) and stimulant and cannabis concurrent exposure (aOR, 1.69; 95% CI, 1.16, 2.47). Low birthweight was associated with opioids alone (aOR, 1.34; 95% CI, 1.10, 1.63), cannabis alone (aOR, 1.31; 95% CI, 1.13 to -1.52), opioid and cannabis (aOR, 1.61; 95% CI, 1.12 to -2.31), and opioids, stimulants, and cannabis concurrent exposures (aOR, 2.27; 95% CI, 1.43-3.61). Five exposure categories were associated with lower birth weights (adjusted mean difference range. -72 to -211 g). Small for gestational age was associated with opioids alone (aOR, 1.48; 95% CI, 1.24-1.78), cannabis alone (aOR, 1.49; 95% CI, 1.31-1.69), and opioids and cannabis concurrent exposures (aOR, 1.91; 95% CI, 1.36-2.67). CONCLUSIONS: We showed complex associations between in utero substance exposures, preterm birth, birth weight, and sociodemographic factors in a rural population. The results may inform policy efforts to improve maternal and child health in socioeconomically disadvantaged and underserved rural populations.