Acquisition of cognitive and communication milestones in infants with Down syndrome

Background: Understanding the timing of developmental milestones in typical and clinical populations facilitates intervention planning and the early detection of risk for co-occurring conditions. Normative timing of developmental milestone achievement has been established for typically developing children. However, there is little information regarding the timing of cognitive and communication skill acquisition in young children with Down syndrome (DS). The objectives of this study are to (1) provide foundational information regarding the timing of cognitive and communication skill acquisition in infants with DS and (2) facilitate the early identification of infants with risk for co-occurring conditions. Method: Seventy-four infants with DS (age range: 4–18 months) completed the Bayley Scales of Infant Development-III (Bayley 2006). Individual items from the cognitive and communication scales were selected for analysis. Parents provided information regarding their infant's developmental and family history. Results: The percentage of infants who attained each skill was calculated within 2-month age bands. For infants who did not show skill acquisition within each age band, the rates of prematurity, heart defects, corrective heart surgery and significant illness were calculated as well. Conclusions: This study provides foundational information that can contribute to the formulation of a developmental schedule for cognitive and language milestone acquisition in infants with DS.