Neonatal hyperviscosity association with lower achievement and IQ scores at school age.

A longitudinal study was conducted to determine whether the early neurologic and motor impairment observed in children with neonatal polycythemia and hyperviscosity persisted into school age. Forty-nine children who had neonatal polycythemia and hyperviscosity were evaluated at a mean age of 7 years. Of these, 21 (group 1) received a partial plasma exchange transfusion, whereas 28 (group 2) received symptomatic care. Forty control children (group 3) with a normal neonatal hematocrit were also evaluated. Testing consisted of a battery of measures to evaluate IQ, achievement, neuromotor function, and gross and fine motor skills. Maternal education and IQ were also assessed to avoid potential confounding by differences in the home environment. The neonatal course of the children with polycythemia and hyperviscosity was characterized by an increased number of problems, including hypoglycemia and cyanosis. At 7 years of age, the 49 children who had hyperviscosity (groups 1 and 2) had significantly lower "spelling" and arithmetic achievement test results and gross motor skill scores. Scores for reading, visual motor integration, and neurologic signs did not differ significantly from group 3. Maternal IQ scores were similar for both groups. Left-hand preference was seen in 14% of group 1 and 2 children and 7% of group 3 children (not significant). The scores for IQ, achievement, neuromotor function, and visual motor integration were compared for the hyperviscosity group (groups 1 and 2) and the control group (group 3) by multivariate analysis of variance with sex and hyperviscous group as independent variables and maternal education and maternal IQ as covariates (P = .040).(ABSTRACT TRUNCATED AT 250 WORDS)