Delayed villous maturation in term placentas exposed to opioid maintenance therapy: a retrospective cohort study

Delayed villous maturation was more common in the placentas of women exposed to opioid maintenance therapy. Further studies are required to characterize rates and extent of delayed villous maturation in the general population as well as to differentiate between possible effects of opioid exposure (eg, heroin, illicit use of prescription opioids) vs those of opioid maintenance therapy (buprenorphine and methadone).