Cognitive measure stability in siblings following early nutritional supplementation.

Cognitive data were obtained on 19 of the 21 pairs of siblings who had been in the authors' earlier study of behavioral outcomes associated with participation in the Special Supplemental Food Program for Women, Infants, and Children (WIC). The timing of WIC participation differed for the members of the sibling pairs, beginning in the perinatal period for one sibling and after 1 year of age for the other. The perinatally supplemented siblings received WIC services for an average of 22 months longer than the siblings whose supplementation began at 1 year of age. The present study determined that enhancements in IQ scores proved stable on blind retesting 32 months after the original study, with those siblings who were supplemented perinatally (and for a longer duration) continuing to exhibit higher scores. The group differences in school grade point averages were in the expected direction at followup, but fell short of statistical significance.