Developmental trajectories of infants born at less than 30 weeks' gestation on the Bayley-III Scales.

Objective: To describe the cognitive, language and motor developmental trajectories of children born very preterm and to identify perinatal factors that predict the trajectories.

Design: Data from a cohort of 1142 infants born at <30 weeks' gestation who were prospectively assessed on the Bayley Scales of Infant and Toddler Development, third edition (Bayley-III) at 3, 6, 12 and 24 months corrected age, were analysed using the Super Imposition by Translation and Rotation (SITAR) growth curve analysis model.

Main Outcome Measures: Developmental trajectory SITAR models for Bayley-III cognitive, language (receptive and expressive communication subscales) and motor (fine and gross motor subscales) scores.