Gross Motor Trajectories During the First Year of Life for Preterm Infants With Very Low Birth Weight.

Background: Early identification of motor dysfunction in preterm infants with very low birth weight (VLBW) is important in order to provide early intervention.

Objective: This study was to examine the motor trajectories of preterm infants with VLBW during their first year of life and to investigate the predictive ability and influencing factors of the trajectories.

Design and Methods: A total of 342 preterm infants with VLBW were prospectively assessed for motor development by the Alberta Infant Motor Scales at 4, 6, 9, and 12 months and for developmental outcomes using the Bayley Scales of Infant and Toddler Development, second edition, at 24 months. Perinatal and socio-environmental factors were collected at baseline. Growth mixture modeling was used to explore the patterns of infants' motor trajectories during their first year of life. Logistic regression analyses were applied to examine the influencing factors associated with motor trajectories and their predictability of 24-month developmental outcomes.

Results: Preterm infants with VLBW showed 3 distinct motor trajectories: stably normal (55%), deteriorating (32%), and persistently delayed (13%). Furthermore, the motor trajectories were predictive of 24-month cognitive and motor outcomes. Perinatal factors including lower birth weight, male gender, moderate to severe bronchopulmonary dysplasia, stage III to IV retinopathy of prematurity, and major brain damage were associated with a risk of deteriorating and persistently delayed trajectories (all P < .05). Socio-environmental factors had no association with motor trajectories.

Limitations: The small sample size of the infants with a persistently delayed trajectory may have limited the assessment of some influencing factors.

Conclusion: The identified early motor trajectories, predictive values, and influencing factors provide insightful implications for early detection and prevention of motor -disorders in preterm infants with VLBW.