Objective: To evaluate the intelligence, visuo-motor perception, emotional problems and preschool skills in low birth weight (LBW) infants and the impact of social and environmental factors on their development.
Design: A prospective cohort study.
Setting: Infants discharged from a Neonatal Special Care Unit of a referral hospital with birth weight less than 2000 g followed up in the High Risk Clinic.
Methods: Low birth weight infants were assessed by Stanford Binet Scales of intelligence, Bender Gestalt Test for visuo-motor perception, Human Figure Drawing for emotional indicators and occupational therapy assessment. A detailed evaluation of their environment and socio-economic status was done. Hearing and ophthalmic assessment was also done and the school progress report was scrutinized.
Results: Two hundred and one LBW and seventy one control children were assessed. The mean IQ of LBW children was within normal limits (94.3), though significantly lower than controls (101.3). Preterm SGA children had the lowest mean IQ. Visuo-motor perception and preschool skills and language development was poorer in LBW children. There was no difference in the emotional indicators. Thirteen per cent of LBW children had borderline IQ, as compared to 5.6% in controls (p<0.05). Mother's education and spaciousness of the house had a positive impact and chronic medical problems had a negative impact on the IQ.
Conclusions: The mean IQ of LBW children was within normal limits. The incidence of children with borderline intelligence (IQ 70-85) was significantly higher than controls. Mother's education had a positive impact on the intelligence of the children. A longer follow up is necessary to identify "slow learners".