Gender and NAS: Does Sex Matter?

Drug Alcohol Depend. 2010 Nov 1;112(1-2):156-9. doi: 10.1016/j.drugalcdep.2010.05.015. Epub 2010 Jun 23.


Background: Neonatal abstinence syndrome (NAS) is a constellation of symptoms resulting from in utero exposure to opioids that appears in 30-80% of opioid exposed infants. Variability in NAS symtomatology is not well understood, and recently it has been suggested that the sex of the infant may play a role in predicting NAS severity. The current study examines the relationship of sex to need for NAS treatment, length of NAS treatment, and peak dose of medication required to treat NAS symptoms.

Methods: Retrospective chart review of 308 infants was conducted to determine whether significant differences exist between male and female neonates in need for NAS treatment, length of treatment and peak dose of medication required. Chi-square, multiple ordinary least squares regression, and analysis of variance (ANOVA) analyses were conducted.

Results: No significant differences were found in need for NAS treatment, length of treatment or peak dose of medication required between male and female neonates.

Conclusions: Results suggest that no significant differences exist in NAS severity between male and female infants.

MeSH terms

  • Analgesics, Opioid / adverse effects*
  • Female
  • Humans
  • Infant, Newborn
  • Male
  • Methadone / therapeutic use
  • Morphine / administration & dosage
  • Neonatal Abstinence Syndrome* / drug therapy
  • Neonatal Abstinence Syndrome* / economics
  • Neonatal Abstinence Syndrome* / therapy
  • Opiate Substitution Treatment
  • Opioid-Related Disorders / drug therapy
  • Pregnancy
  • Pregnancy Complications / drug therapy
  • Retrospective Studies
  • Risk Factors
  • Sex Characteristics


  • Analgesics, Opioid
  • Morphine
  • Methadone