The impact of infant feeding method on neonatal abstinence scores of methadone-exposed infants

Adv Neonatal Care. 2011 Aug;11(4):282-90. doi: 10.1097/ANC.0b013e318225a30c.


Purpose: To determine whether neonatal abstinence scores of infants exposed to methadone in utero differed by infant feeding method.

Design: A retrospective chart review.

Subjects: Twenty-eight term infants that were exposed to methadone in utero and exhibited symptoms of neonatal abstinence syndrome (NAS) prior to hospital discharge were included into the study. The sample was further divided by self-selected infant feeding method including (1) predominately breastfed (n = 8), combination fed (n = 11) or predominately formula fed (n = 9).

Methods: Data were extracted by two independent researchers from both the mother's and infant's chart. This included variables such as NAS scores, NAS treatment, infant feeding method and baseline demographic information.

Main outcome measures: NAS scores were assessed by Registered Nurses according to hospital protocol using a Modified Finnegan Scoring Tool.

Principal results: A non-parametric Kruskal-Wallis one way analysis of variance based on ranks revealed statistically significant differences in the number of NAS scores recorded (P = 0.001), magnitude (P < 0.0001) and area score (P = 0.04) by infant feeding method. In particular, infants who were predominantly breastfed had significantly fewer NAS scores done and lower mean scores suggesting decreased severity and duration of NAS symptoms when compared to infants who were combination fed or predominately formula fed.

Conclusion: Breastfeeding may offer enhanced benefits for infants who have been exposed to methadone in utero. As such, in the absence of contraindications, mothers in methadone maintenance programs should be encouraged and supported to breastfeed their infants.

MeSH terms

  • Adolescent
  • Adult
  • Analysis of Variance
  • Breast Feeding* / psychology
  • Female
  • Humans
  • Infant Formula*
  • Infant, Newborn
  • Male
  • Methadone / adverse effects*
  • Methadone / therapeutic use
  • Neonatal Abstinence Syndrome / diagnosis*
  • Neonatal Abstinence Syndrome / therapy*
  • Ontario
  • Opioid-Related Disorders / drug therapy
  • Pregnancy
  • Prenatal Exposure Delayed Effects / therapy
  • Retrospective Studies
  • Severity of Illness Index
  • Young Adult


  • Methadone