1. In a pregnant women, the oxygen supply for the fetus is provided by the maternal blood in the placenta where the blood vessels of both mother and fetus arc in close proximity.
Both fetal and maternal hemoglobin binds to oxygen reversibly as follows.
Hb(mother) + O2 ⇌ HbO2(mother)
Hb(fetus) + O2 ⇌ HbO2(fetus)
2. In the above two equilibrium, the equilibrium constant value for the oxygenation of fetal hemoglobin is higher which is due to its higher affinity for oxygen compared to adult hemoglobin. Hence in placenta, the oxygen from the mother’s blood s effectively transferred to fetal hemoglobin.
