Exposure to a chloride-deficient formula during infancy: outcome at ages 9 and 10 years.

A school-based survey of the 1978 to 1979 birth cohort of two metropolitan Washington, DC, counties was conducted to find children who had been exposed to the chloride-deficient formulas Neo-Mull-Soy and Cho-Free during infancy. Children who had ingested other soy formulas that had an adequate chloride content were also found and matched to the exposed children by sex, race, birth weight, the age of the child, the mixed feeding status of the child, and maternal education. One hundred seventy-one of the exposed children and 261 soy control children were given a battery of psychologic tests in their homes to determine whether there had been any effect on intellectual development as a result of exposure to the chloride-deficient formulas. There were no differences in scores between the groups on the Wechsler Intelligence Scale for Children-Revised, the Boston Naming Test, the Rey-Osterrieth Test, or the FAS Verbal Fluency Test. There was no correlation between duration of exclusive exposure to the chloride-deficient formulas and the Wechsler Intelligence Scale for Children-Revised Full-Scale IQ Score (Pearson product-moment r = -.0825, P = .28). These results cannot be extrapolated to exposed children with documented hypochloremic metabolic alkalosis. It is concluded that in children without documented evidence of hypochloremic metabolic alkalosis, exposure to the chloride-deficient formulas Neo-Mull-Soy or Cho-Free during infancy has not resulted in any long-term adverse effects on cognitive development.