Opioid maintenance treatment in pregnancy: Maternal and neonatal outcomes

Abstract

Methadone maintenance treatment (MMT) is recommended as the standard of care for opioid-dependent pregnant women. Compared to heroin use in pregnancy, MMT is associated with less drug use and better prenatal care. For the neonate, MMT is associated with neonates born closer to term, better fetal growth and reduced fetal mortality. The overall study aim was to explore the maternal and neonatal outcomes when women were in OMT during pregnancy. The design is a mixed prospective/retrospective national cohort study of 139 pregnant women in OMT and their 161 neonates born between 1996 and 2009. A standardized questionnaire was administered and medical information was collected from the hospitals and municipalities. Buprenorphine-exposed neonates had significantly larger head circumferences and tended to be heavier and longer than methadone-exposed neonates. There were no differences in the incidence or duration of treatment of neonatal abstinence syndrome (NAS) between the medications. There were high initiation rates of breastfeeding (77%) for women in OMT. Breastfed neonates exposed to methadone prenatally had significantly lower incidence of NAS requiring pharmacotherapy and both the whole group of infants and methadone-exposed neonates needed shorter pharmacological treatment of NAS. Two of the woman came off the OMT medication during pregnancy and another 15% tapered their OMT medication more than 50%. The birth weights of methadone-exposed neonates of women who tapered more than 50% were significantly higher than for the methadone-exposed neonates of the women tapering between 11 and 50%. No other significant differences were found between the tapering groups. The case report describes a well-functioning woman in OMT who tapers her buprenorphine dose from 24 mg to zero during pregnancy. In line with other studies, our results indicate that both methadone and buprenorphine are acceptable medications for use in pregnancy.