Abstract 1399 Poster Session III, Monday, 5/3 (poster 10)

Background: Evaluations of very low birth weight infants have traditionally focused on scores from the Bayley Scales of Infant Development emphasizing the Mental Development Index (MDI) and the Psychomotor Development Index (PDI). Although the Bayley II includes a Behavior Rating Scale, data utilizing this scale have not been extensively reported to describe very low birth weight populations. Recent research reports have suggested that very low birth weight infants experience a high incidence of behavior problems when they reach school age. The purpose of this study was to determine if very low birth weight children have abnormal behavioral patterns which could be detected at an early age using the Bayley BRS. Methods: The population consists of children born at JMH/University of Miami School of Medicine with a birth weight ≤ to 1000 g born between February 10, 1993 and June 10, 1996 who were assessed using the Bayley Scales of Infant Development II at 18 months of age. The Bayley Behavior Scale Manual assigns scores as Normal, Questionable and Non-Optimal with an expected frequency of 75%, 14% and 10%, respectively. The behavior category scores were evaluated in relation to Mental and Motor Development scores. Behavior Rating scores were also related to a number of social and medical variables. Social Variables included ethnicity, mother's educational level, income, marital status and whether or not the mother received prenatal care. Medical variables included sex, gestational age, birth weight, apgar score <5, use of drugs in resuscitation, the presence of IVH, grade of IVH, diagnosis of leukomalacia, necrotizing enterocolitis, use of maternal steroids, days requiring ventilator support, days on oxygen and number of days to discharge. Results: Forty percent of the infants assessed scored in the Non-Optimal range at 18 months, 21% in the Questionable Range and 39% in the Normal category. Analysis of variance showed a relationship between the Behavior Rating scores and both the Mental and Motor Development scores (p.< 001). Infants who scored in the NonOptimal category had lower Mental and motor development than those who scored in the Normal Range. More girls than boys fell within the Normal category on the Behavior Rating Scale (p. < .01). None of the other medical factors assessed were related to Behavior rating category at 18 months. Social factors were not related to behavior scores. Discussion: The results of this study suggest that a large percentage of very low birth weight infants are displaying Non-Optimal behavior by the age of 18 months and this behavior is associated with decreased Mental and Motor scores on the Bayley. Underlying factors related to Non-Optimal scores do not appear to include the typical social risk factors nor the medical risk variables common in this premature, very low birth weight populations.