CHICAGO – Methadone was associated with a significantly higher incidence of neonatal abstinence syndrome (NAS), compared with babies born to mothers who took buprenorphine for opioid maintenance therapy during pregnancy, a retrospective study of 204 neonates revealed.
Interestingly, among babies who developed the syndrome, the duration of treatment and length of stay did not differ significantly between groups.
“We found buprenorphine decreases [the incidence of] NAS,” said Alla Kushnir, MD, an attending neonatologist at Cooper University Hospital in Camden, N.J. The findings also demonstrate that physicians can expect to see “about the same withdrawal once they withdraw,” regardless of whether the mother took methadone or buprenorphine during pregnancy.
“We can’t make it better, but we can prevent some neonatal abstinence syndrome,” Dr. Kushnir said in an interview at the annual meeting of the American Academy of Pediatrics.
Dr. Ravi Bhavsar
The infants in the study were admitted to the neonatal ICU between July 2010 and June 2016. The mothers self-reported prenatal use of methadone, buprenorphine, other opioids and/or various illicit drugs, or tested positive on a urine screen during pregnancy. In the methadone group, 81% of infants developed NAS, compared with 50% of those in the buprenorphine group. The higher likelihood of developing NAS from methadone-treated mothers was statistically significant (P less than .001).
The study population included some women who reported taking additional drugs. Among 65 infants born to women who combined methadone with other agents, 58 (89%) developed NAS. In addition, all seven infants (100%) born to women who took buprenorphine and other drugs developed the syndrome.
“Methadone was the clear bad guy in terms of incidence” between the two drugs, said Ravi Bhavsar, MBBS, a research assistant at the hospital.
Among the infants who developed NAS symptoms, the hospital length of stay and duration of medical treatment – indicators of syndrome severity – did not differ significantly (P = .015).
“This study also tells us that more research needs to be done,” Dr. Bhavsar said. Methadone is a mainstay of opioid maintenance therapy, he added, and additional evidence is warranted before shifting recommendations toward buprenorphine.
Dr. Kushnir and Dr. Bhavsar reported having no relevant financial disclosures.