2,3-Diphosphoglycerate in normal, anaemic and transfused human fetuses.

1. The effect of anaemia and transfusion with adult blood on fetal 2,3-diphosphoglycerate levels was investigated by studying fetal blood from 45 normal pregnancies at 17-42 weeks of gestation and in 34 pregnancies complicated by erythroblastosis fetalis. 2. In normal fetuses, 2,3-diphosphoglycerate concentration was higher than in adults and did not change significantly with gestational age. 3. In erythroblastotic fetuses, there was a significant negative correlation between 2,3-diphosphoglycerate concentration and haemoglobin concentration. 4. When adult blood was transfused into the fetal circulation, 2,3-diphosphoglycerate concentration reached similar levels to that found in untransfused fetuses after allowing for the severity of anaemia.