Open AccessRed Cell 2,3‐Diphosphoglycerate and Hemoglobin‐Oxygen Affinity During Diabetic Pregnancy
Author(s) -
Madsen H.,
Ditzel J.
Publication year - 1984
Publication title -
acta obstetricia et gynecologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.401
H-Index - 102
eISSN - 1600-0412
pISSN - 0001-6349
DOI - 10.3109/00016348409156692
Subject(s) - hemoglobin , medicine , pregnancy , diphosphoglycerate , oxygen–haemoglobin dissociation curve , fetal hemoglobin , endocrinology , red cell , hemoglobin f , oxygen transport , diabetes mellitus , red blood cell , anemia , oxygen , fetus , chemistry , biology , genetics , organic chemistry
. Factors involved in blood oxygen transport were measured serially in the first, second and third trimester of pregnancy in 23 insulin‐dependent diabetic women. Twenty‐six non‐pregnant diabetic patients served as a reference group. Diabetic pregnancy was associated with relative anemia, a significant increase in arterial pH, and hypocap‐nia. The concentration of red cell 2,3‐diphosphoglycerate was significantly higher in the first trimester of diabetic pregnancy compared with non‐pregnant diabetics (median value 16.4 vs. 15.0 μmol/g hemoglobin, p>0.02) and increased gradually from the first to the third trimester (16.4 to 17.2 μmol/g hemoglobin, p<0.01). The hemoglobin A 1c concentration decreased simultaneously from 8.1% to 7.3% (p <0.01). The level of hemoglobin A 1c in the first trimester was significantly lower than that in the non‐pregnant diabetic patients (8.1 vs. 9.3%, p>0.01). In spite of the increase in red cell 2,3‐diphosphoglycerate content and the decrease in hemoglobin A 1c , factors known to reduce hemoglobin oxygen affinity, the position of the oxyhemoglobin dissociation curve remained unchanged during diabetic pregnancy: P 50 at actual pH in the first trimester, was 26.0 mmHg; in the second trimester, 26.9 mmHg, and in the third trimester, 26.8 mmHg (NS). These values of P 50 at actual pH were identical with the value in the non‐pregnant group (26.6 mmHg). Other factors influencing hemoglobin oxygen affinity, such as hemoglobin concentration, hydrogen ion concentration and arterial oxygen saturation remained unchanged during diabetic pregnancy. The observations suggest that an unknown factor which increases hemoglobin oxygen affinity and to which the increased level of red cell 2,3‐diphosphoglycerate may be compensatory, is operating in diabetic pregnancy.