Patterns of 1-day and 4-month motor functioning in infants of women on methadone.

Motor functioning of 38 infants, 15 exposed in utero to methadone, was assessed on Brazelton Neonatal Behavioral Assessment Scale with Kansas Supplements (NBAS-K) (Items: General Tonus, Motor Maturity, Activity, and Tremulousness) at 1 day, and at 4 months on Bayley Infant Behavior Record (IBR) (Items: Tension, Activity, Interest in Body Motion, Gross Coordination, and Fine Coordination). At 4 months, methadone infants generally showed a profile of poorer motor coordination, greater tenseness and interest in body motion, and higher activity level than did non-methadone infants. Guttman's Multidimensional Scalogram Analysis (MSA) of the 5 IBR motor-item profiles showed that a line can be drawn that almost perfectly discriminates the methadone and non-methadone infants by their joint performance on these 5 variables. A scatterplot of each infant's sum scores of the Brazelton versus IBR motor items revealed a significant correlation between 1-day and 4-month motor functioning. Methadone infants showed poorer motor functioning at both ages. This analysis of behavioral continuity again revealed an almost perfect discrimination between the two groups.