The apparent fall in haemoglobin concentration during pregnancy has been considered presumably the outcome of the hydraemia of pregnancy. But, on the most urgent problems is that pregnant women may be exposed to iron defficiency for synthesis of the haemoglobin molecule to fill the increase in blood volume or foetal demands. In this point of view, I have tried to analyse the haemodynamics of pregnancy. In early stage of pregnancy, haemoglobin level starts to fall, as compared with that of none-pregnant stage, and remains substantially decreased in late stage of pregnancy. The fall in haemoglobin commonly found in early stage is largely due to the plasma dilution without iron defficiency, and the total circulating haemoglobin increases gradually in amount. The haemoglobin concentrations of pregnant women who keep the normo-chromic state during pregnancy show above the corresponding average levels to late pregnancy, and recover slowly in puerperium. On the other hand, the haemoglobin levels of the cases followed by the drops in serum iron and hypo-chromic state show the apparent fall in late stage of pregnancy, and do not recover until 4 weeks of puerperium. In the cases of administration of iron to pregnant women from 5 months of pregnancy to terms of pregnancy, their haemoglobin concentrations are always kept significantly high levels above that of none-administered cases.
There is no significant difference between the each of the haemoglobin concentrations of infants, delivered of pregnant women who are divided into three groups, normo-chromic state, hypo-chromic state, and iron-administered state.
