A Nutritional Study of Anemia in Pregnancy Hematologic Characteristics in Pregnancy (Part 1) Keizo Shiraki, Fumiko Hisaoka Department of Nutrition, School of Medicine, Tokushima University, Tokushima Fetal development is accompanied by extensive changes in maternal body compositions and metabolism, and the severe anemia during pregnancy also has great influences not only upon the mother but also upon the fetus and the newborn. It is clear that clinical standards considered "normal" for the non-pregnant women cannot be used as standards for pregnant women because of the big hemodilution in pregnancy. By our observations, the hemoglobin concentration decreased on average by 14.0%, while the plasma volume and blood volume increased on average by 49.8% and 23.3%, respectively. In an attempt to make a hematological standard for the gravid Japanese woman, measurments of the total hemoglobin and red cell mass were made on 112 pregnant women (IIIrd trimester) without any selection of cases, who were residents of Tokushima City. By using the statistical analysis, anemia of the gravid woman was defined as follows: the total hemoglobin below 9.0g/kg, and the red cell mass below 25ml/kg, taking a range of 2 S.D. from the mean. But these standards seemed not too convenient for the practical use for group examination of pregnant women. Accordingly, the hemoglobin concentration less than 10.0g/dl in the venous blood was designed as anemia in pregnancy, since the highest correlation was found on it with the total hemoglobin and red cell mass. On the other hand, the red cell count and the hematocrit were found less usefull for the indicators of anemia in pregnancy. The incidence of anemia in pregnancy by this standard was 16.9% (35 women out of 206), and the anemia was of the normocytic, hypochromic type and was accompanied by low serum iron values.(received December 4, 1971)
Table 1. Hematologic data in pregnancy Table 2. Total circulating hemoglobin and red cell mass in pregnancy Total circulating hemoglobin (T-Hb) was calculated by multiplying circulating blood volume by Hb concentration, and red cell mass (RCM) was estimated by dividing circulating blood
Table 3. Circulating blood volume and plasma volume in pregnancy Table 5. Lower limits of normal levels of the hematologic measurements in pregnancy Lower limit was calculated taking out of confidence limit including 95% of population. Fig. 1. (a) is a histogram of the hemoglobin concentration in pregnancy and (b) shows its normal distribution, since a straight line on the probability paper indicates that hemoglobin concentration distributes normally.
Table 6. Correlation coefficient of various hematologic parameters in pregnancy Correlation coefficient was calculated by the least square technique.* means values are statistically significant at the level of p<0.001, and** does at the level of p<0.01. Table 7. Incidence of anemia in pregnancy Incidences of anemia of the two groups are statistically significantly different at the level of p<0.05.