FRIDAY, Nov. 13, 2026 (HealthDay News) -- Lowering doses of medication to treat opioid use disorder (OUD) during pregnancy is not an effective strategy for preventing severe neonatal opioid withdrawal syndrome (NOWS), according to a research letter published online Oct. 29 in JAMA Network Open.Courtney Townsel, M.D., from the University of Maryland in Baltimore, and colleagues examined whether umbilical cord opioid concentrations, as a measure of fetal opioid exposure, are associated with NOWS severity. The analysis included 92 pregnant individuals with OUD who continuously received methadone or buprenorphine treatment for at least 30 days before delivery.The researchers found that severe NOWS occurred in 41 neonates (43.6 percent) and was more common in methadone- than buprenorphine-exposed neonates (33 versus 11 neonates). In an adjusted analysis, methadone exposure remained associated with increased odds of severe NOWS (adjusted odds ratio, 3.42). There was a positive correlation between maternal methadone dose and umbilical cord methadone (ρ = 0.64) and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine levels (ρ = 0.45). There was no significant association between maternal buprenorphine dose and cord buprenorphine or norbuprenorphine levels. There was no difference in umbilical cord opioid concentrations between severe and nonsevere NOWS."Our results indicate higher exposure did not lead to worse withdrawal in newborns," Townsel said in a statement. "Cutting the dose doesn't give the baby an easier withdrawal. It only puts the mother at risk."Abstract/Full Text.Sign up for our weekly HealthDay newsletter