The clinical relevance of these findings is that both methadone and buprenorphine are acceptable medications for the use in pregnancy, in line with previous studies. If starting OMT in pregnancy, buprenorphine should be considered as the drug of choice, due to more favorable neonatal growth parameters. Early confirmation of the pregnancy and systematic follow-up throughout the pregnancy are of importance to encourage the women in OMT to abstain from the use of tobacco, alcohol, illegal drugs or misuse of prescribed drugs.

Background: Opioid maintenance treatment (OMT) is widely used to treat pregnant women with a history of opioid dependence. This study investigated whether maternal methadone/buprenorphine dose and nicotine use in pregnancy affects the occurrence and duration of neonatal abstinence syndrome (NAS) in the infant. Methods: Forty-one pregnant women from OMT programmes in Norway who gave birth between January 2005 and January 2007 were enrolled in a national prospective study. Thirty-eight women (81% of the population) were interviewed in the last trimester of pregnancy and 3 months after delivery. Data from the European Addiction Severity Index and a questionnaire measuring enrolled birth information were compared with medical records and urine analyses. Results: Treatment requiring NAS occurred in 58% of the methadone-exposed and in 67% of the buprenorphine-exposed infants. There was no significant relationship between a maternal dose of methadone or buprenorphine in pregnancy and NAS treatment duration for the infant. The mean number of cigarettes consumed correlated significantly with NAS treatment duration for the methadone group. Birth weight for the methadone group was approximately 200 g above international findings despite high doses during pregnancy. Conclusions: Maternal methadone/buprenorphine dose predicted neither the occurrence nor the need for NAS treatment for the infant.

Breastfed neonates exposed to OMT medication prenatally, and methadone-exposed newborns in particular, have lower incidence of NAS and require shorter pharmacotherapy for NAS than infants who are not breastfed. The results add to the evidence regarding the benefits of breastfeeding for neonates prenatally exposed to OMT medications.

Given that buprenorphine + naloxone is prescribed for opioid-dependent pregnant women, it is important to examine the extent to which it differs from buprenorphine alone, methadone, or methadone-assisted withdrawal on neonatal and maternal outcomes. Summary statistics on maternal and neonatal outcomes were collected from 7 previously published studies examining treatment for opioid-dependent pregnant women that represented a range of research methodologies. Outcomes from these studies were compared to the same outcomes for 10 women treated with the combined buprenorphine + naloxone product. There were no significant differences in maternal outcomes for buprenorphine + naloxone compared to buprenorphine, methadone, or methadone-assisted withdrawal. Preliminary findings suggest no significant adverse maternal or neonatal outcomes related to the use of buprenorphine + naloxone for the treatment of opioid dependence during pregnancy. However, further research should examine possible differences between buprenorphine + naloxone and buprenorphine alone or methadone in fetal physical development.