Women exposed to opioid maintenance therapy (OMT) experienced delayed villous maturation (DVM) in the placenta more often than women not exposed to OMT, a recent study found. The retrospective cohort study was conducted between 2010 and 2012 and compared delayed villous maturation in placentas of women with opioid use disorder exposed to either buprenorphine (n=86) or methadone (n=268) to women without opioid use disorder (n=978). Researchers found:

• DVM was identified in 5.7% of placentas among women without opioid use disorder and in 8.1% and 10.8% among women treated with buprenorphine or methadone, respectively.
• Those exposed to OMT had significantly greater odds of being diagnosed with DVM compared to those not exposed (OR, 1.86).
• Women treated with methadone had significantly greater odds of having a placenta with DVM than women without opioid exposure to OMT (OR, 2.00), while women treated with buprenorphine did not have significantly greater odds of this diagnosis compared to women unexposed to OMT (OR, 1.46).