Frequency of newborn behaviours associated with neonatal abstinence syndrome: a hospital-based study

To determine the frequency of neonatal abstinence syndrome (NAS) among unselected term newborns, using newborn behaviour data only.

This hospital-based prospective exploratory study used clinical observations of newborn behaviours, mothers' observations of their newborns, and newborn chart data to determine the prevalence of suspected and confirmed cases of NAS in a convenience sample of unselected term newborns "rooming in" with their mothers in a large central city acute-care referral hospital. Over a 4-month period, 824 out of 1008 newborns were observed at between 8 and 30 hours of life by specially trained nurse observers. Behaviours recorded and their weighting were adapted from the Neonatal Abstinence Scoring System (NASS) by Finnegan and Kaltenbach. Newborns with scores of 5 or greater and "suspect for NAS" were referred to their physicians for confirmation or refutation of the clinical findings. The prevalence of "suspect for NAS" and confirmed NAS, as well as of individual neonatal behaviours, was calculated.

Thirty-one (3.8%) of 824 term "rooming in" newborns were identified with findings suggestive of NAS. Four newborns were positively identified as having NAS and treated. The identification was confirmed by post hoc affirmation of maternal drug use. Individual behaviours occurring in 10% or more of newborns included excessive sneezing, nasal stuffiness, unsustained suck, tremor, and abnormal nipple latch.

Clinical observation of newborn behaviour may identify NAS. Further studies are recommended to correlate this methodology with laboratory findings, as are more in-depth maternal questionnaires concerning use of mood-altering substances. The prevalence of NAS is likely underestimated because of early hospital discharge. A coordinated system of early identification and infant-specific assessment and treatment, both in hospital and following discharge home, is advocated.