Changes of hemoglobin values in venous blood during pregnancy

: In order to establish new diagnostic criteria for anemia of pregnancy on the basis of physiologic changes in Hb values during pregnancy, 4,670 measured values of Hb in venous blood during pregnancy, which were obtained by the cyanmethemoglobin method from 1,000 pregnant women, were examined. The blood samples were collected at two-week intervals between the 4th and 39th weeks of pregnancy. The following results were obtained. Significant correlations between Hb values and serum iron values, total iron binding capacity values, transferrin values and serum total protein values were observed. The following diagnostic criteria for anemia of pregnancy were proposed: M. +/- S.D. of Hb as the lowest normal value and considering the actual rate of distribution, 11.5 g/dl of Hb at 6 +/- 1 weeks of pregnancy, 10.5 g/dl at the 16 +/- 1 weeks, 10.0 g/dl at 28 +/- 1 weeks, 10.0 g/dl at 32 +/- 1 weeks and 10.5 g/dl at 36 +/- 1 weeks (based on results obtained in the Yokosuka district). The lowest value for Hb and the maximum rate of decrease during pregnancy available for the diagnosis of anemia of the pregnancy are reported.