Objective: To determine specific sleep characteristics in neonatal opiate withdrawal, referred to as the Neonatal Abstinence Syndrome (NAS), by measuring sleep efficiency, deprivation, disorganization and fragmentation in three groups: (i) healthy term neonates; (ii) opiate-exposed neonates who were treated for opiate withdrawal; and (iii) a group of opiate-exposed neonates who did not require treatment.
Methods: A cohort study recording sleep patterns of neonates at 2-10 days of age (after 36 or more weeks of gestation) was carried out. Twenty-one neonates were exposed to opiates during pregnancy and 15 neonates were healthy controls. Sleep characteristics were predefined, and treated newborns were divided into early and stabilized treatment groups. Polygraphic recordings of sleep, movement and breathing were made continuously after a daytime feed.
Results: Sleep deprivation, disorganization and fragmentation were found in newborns with NAS and were associated with the severity of the withdrawal. Neonates treated for NAS displayed increased wakefulness during early treatment (deprivation), but were similar to controls once stabilized. Both treated and non-treated groups had reduced amounts of quiet sleep (deprivation). Treated newborns showed an increase in indeterminate sleep (disorganization) and arousals-to-wakefulness (fragmentation).
Conclusion: This study determined the exact nature and degree of sleep disturbances in newborns during acute opiate withdrawal. The findings contribute to a further understanding of the physiology underlying neonatal opiate withdrawal and suggest that some changes in sleep are due to opiate withdrawal but others may reflect opiate dependency in utero.