Perinatal, Neonatal, Developmental and Demographic Predictors of Intelligence at 4 years of Age Among Low Birth Weight Children: a Panel Study with a 2-year Follow-up

Intoduction: Childhood intelligence is an important predictor of later outcomes in life such as socioeconomic status or health. Hence, a deeper understanding of predictors of child intelligence should suggest points of intervention for children facing adversities.

Objectives: The purpose of this study is to examine the predictive value of demographic, perinatal and neonatal variables after birth and developmental characteristics at age 2 for 4-year intelligence as outcome among low birth weight children.

Methods: We designed a panel study with a 2-year follow-up with 114 child-mother pairs. The outcome variable was IQ intelligence quotient at 4 years of age of LBW low birth weight children measured by the Wechsler Primary and Preschool Scales of Intelligence. Potential predictors were maternal education, family wealth, ethnic identity; sex, twin pregnancy, gestational age, birth weight, Apgar scores, maternal smoking during pregnancy; diagnosis of intravetricular haemorrhage, retinopathy of prematurity, bronchopulmonary dysplasia after birth and cognitive, language and motor development at age 2 measured by one composite score of the three Bayley Scales of Infant and Toddler Development aggregated.

Results: Stepwise backward regression was carried out including significant variables from the bivariate analysis. The best model included 4 predictors which accounted for 57% of the variance of the full IQ intelligence at 4-years of age. Maternal higher education was significant positive, below average family wealth and neonatal diagnosis of bronchopulmonary dysplasia were significant negative predictors in the model after birth. 2-year developmental characteristics such as cognitive, motor and language skills were positive predictors of the IQ intelligence at age 4.

Conclusion: Sociodemographic assessment at birth and developmental assessment at two years of age are of crucial importance to recognize children at high risk for delayed cognitive development. High-risk children should be directed to supportive interventions and their development should be regulary monitored.