A comparison of the effects of single- and split-dose methadone administration on the fetus: ultrasound evaluation

Int J Addict. 1991 Feb;26(2):213-8. doi: 10.3109/10826089109053183.


A prospective study was conducted to evaluate the effects of oral methadone on fetal activity (body movements, breathing, longest inactive period) for drug-dependent pregnant women on methadone maintenance. Seven consenting drug-dependent pregnant women between 26 and 37 weeks gestation were enrolled in the study. Pairs of ultrasound observation studies were conducted, before and after single-dose methadone (SDM) treatment and split-dose methadone treatment. There were significant decreases in both body movements (p less than 0.001) and breathing episodes (p less than 0.01), and a significant increase in the longest period of inactivity (p less than 0.001) following SDM. A similar but not significant trend was noted before and after split-dose methadone. The results of the single-dose studies differed significantly from normal controls. However, the results of the split-dose studies were similar to controls. It is recommended that women on methadone maintenance should be offered a split-dose treatment protocol.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dose-Response Relationship, Drug
  • Drug Administration Schedule
  • Female
  • Fetal Movement / drug effects*
  • Fetal Movement / physiology
  • Humans
  • Infant, Newborn
  • Methadone / administration & dosage*
  • Neonatal Abstinence Syndrome / physiopathology
  • Opioid-Related Disorders / physiopathology
  • Opioid-Related Disorders / rehabilitation*
  • Pregnancy
  • Pregnancy Complications / physiopathology
  • Pregnancy Complications / rehabilitation*


  • Methadone