Growth and development in children with sickle-cell trait. A prospective study of matched pairs.

To ascertain if sickle-cell trait (Hb AS) impairs physical growth and cognitive development, we prospectively investigated 50 matched pairs of black children. For each child with Hb AS, an Hb AA child was matched at birth for sex, birth date, birth weight, gestational age, five-minute Apgar score and socioeconomic status. Between the ages of three and five years, the members of each matched pair were evaluated, with one month of one another, by persons "blind" to the hemoglobin genotype. Twelve outcome measurements were obtained at evaluation: height, weight, head circumference, skin-fold thickness, cross-sectional area of arm muscle, bone age, five scores of the McCarthy Scales of Children's Abilities, and the Peabody Picture Vocabulary Test. There were no statistically significant differences in these measurements favoring the AA group. The results show that children with sickle-cell trait in this age group have no deficits in standard measurements of growth and development and emphasize the importance of rigorous methods when clinical groups are assembled and compared.