Aim: To determine the developmental trajectories of very-low-birthweight (VLBW) infants during the first 2 years of life, and investigate the most contributory predictors of diverse trajectories.
Methods: This prospective cohort study enrolled 887 VLBW infants from January 1999 to December 2002 with regular follow-up at corrected age of 6, 12, 18 and 24 months. Sociodemographic and medical data were collected, and the outcome measures consisted of neurological assessment and the Bayley Scales of Infant Development-II.
Results: Five trajectories of cognitive development based on the mental developmental indices from the age of 6 to 24 months were determined, including average-stable (group A, 20.1%), average-decline to borderline delay (group B, 34%), borderline delay-catch-up to average (group C, 20.2%), borderline delay-decline to significant delay (group D, 17.2%) and significant delay-stable (group E, 8.5%). Using group A as the reference category, we determined 6-month neurological status and maternal education as the most significant predictors for various trajectories (p < 0.01). Infants with transient or definite neurological abnormality and/or low maternal education had higher odds of displaying the disadvantageous trajectories (group B, D and E; odds ratios, 1.79-46.4).
Conclusion: VLBW infants with neurological abnormalities and/or low maternal education had high risk of developmental decline and might benefit from early intervention.