Neonatal outcomes and their relationship to maternal buprenorphine dose during pregnancy.

BACKGROUND: Buprenorphine pharmacotherapy for opioid-dependent pregnant women is associated with maternal and neonatal outcomes superior to untreated opioid dependence. However, the literature is inconsistent regarding the possible existence of a dose-response relationship between maternal buprenorphine dose and neonatal clinical outcomes.

METHODS: The present secondary analysis study (1) examined the relationship between maternal buprenorphine dose at delivery and neonatal abstinence syndrome (NAS) peak score, estimated gestational age at delivery, Apgar scores at 1 and 5 min, neonatal head circumference, length, and weight at birth, amount of morphine needed to treat NAS, duration of NAS treatment, and duration of neonatal hospital stay and (2) compared neonates who required pharmacotherapy for NAS to neonates who did not require such pharmacotherapy on these same outcomes, in 58 opioid-dependent pregnant women receiving buprenorphine as participants in a randomized clinical trial.

RESULTS: (1) Analyses failed to provide evidence of a relationship between maternal buprenorphine dose at delivery and any of the 10 outcomes (all p-values>.48) and (2) significant mean differences between the untreated (n=31) and treated (n=27) for NAS groups were found for duration of neonatal hospital stay and NAS peak score (both p-values<.001).

CONCLUSIONS: (1) Findings failed to support the existence of a dose-response relationship between maternal buprenorphine dose at delivery and any of 10 neonatal clinical outcomes, including NAS severity and (2) that infants treated for NAS had a higher mean NAS peak score and, spent a longer time in the hospital than did the group not treated for NAS is unsurprising.