Behavioral characteristics of very-low-birth-weight infants of varying biologic risk at 6, 15, and 24 months of age.

OBJECTIVE: To explore the relationship between developmental outcome and behavior of very-low-birth-weight (VLBW) infants (< or = 1500 g) at high and low biologic risk. DESIGN: Descriptive, ex post facto. SETTING: Clinic for follow-up of infants at high risk. PARTICIPANTS: A convenience sample of 102 VLBW infants, free of major congenital anomalies, who completed 6-, 15-, and 24-month developmental testing and who were part of a larger study of 274 VLBW infants. MAIN OUTCOME MEASURE: Bayley Scales of Infant Development. RESULTS: Infants at high biologic risk, versus infants at low biologic risk, were less attentive and active through age 15 months and were less adept in gross and fine motor skills through age 24 months (p < or = 0.05-0.001). Infants with continuous delay were less attentive than infants with no delay or late delay through age 24 months, less active through age 15 months (p < or = 0.001-0.001), and less skilled in motor behaviors through age 24 months (p < or = 0.05-0.001). CONCLUSION: Infants at high biologic risk and infants with developmental delays are less attentive, less active, and less skilled in motor tasks during the first 15-24 months of life, suggesting an association between biologic risk and behavior and developmental delay and behavior.