Changes in Hb values.

(A) Temporal evolution of Hb values in 3 infants who did not have transfusions during the first weeks of life. Shaded area shows the range of Hb values in healthy infants.13 B shows histograms of Hb values (mean ± SD) before the first transfusion in infants with HS, as a function of postnatal age. The number of infants with HS (n) evaluated at various postnatal ages is indicated (a: n = 19; b: n = 12; c: n = 10; d: n = 8).