Lemon LS, et al. - Researchers carried out this study to evaluate the role of preterm birth as a mediator of the relationship between in utero exposure to methadone and neonatal abstinence syndrome (NAS) compared with buprenorphine. In term deliveries, the further increased risk of NAS correlated with methadone use vs buprenorphine highlighted the utility of buprenorphine in clinical settings aimed at decreasing NAS.