UMBILICAL VEIN SERUM AMINO-ACID LEVELS IN AFRICAN-AMERICANS - RELATIONSHIP TO BIRTH-WEIGHT AND MATERNAL VARIABLES

Compared with other racial groups, African-American women show a dispr oportionately high risk of delivering low birthweight babies. In a ret rospective study of African-American infants born at Meharry Hubbard H ospital, which predominantly serves the underprivileged inner-city poo r, free amino acid concentrations were measured in umbilical venous se rum from infants born following 34 to 42 weeks gestation. Significant reductions in levels of glycine, serine, alanine, the branched-chain a mino acids, and the sum of the so-called dispensable amino acids were associated with decreased birthweight. Glycine, a quantitatively impor tant residue in collagen and a component of reduced glutathione (gamma -glutamyl-cysteinyl-glycine), which is featured in the gamma-glutamyl amino acid transport cycle, was most consistently and severely affecte d. This study not only indicated that selective reduction in transplac ental amino acid transport may be an important factor in intrauterine growth retardation in African Americans, but also confirmed the dietar y necessity of the structurally simple amino acid glycine during pregn ancy.