So when the binding takes place, that adult hemoglobin is much less likely to actually bind oxygen and carry oxygen from point A to point B. Now, what about the fetal hemoglobin? Well, just like the delt hemoglobin, the fetal hemoglobin also consists of four subunits. It contains alpha one and alpha two, as shown in the following diagram. But it doesn't contain beta one and beta two. Instead, it contains a slightly different two subunits gamma one and gamma two.