HUMAN ERYTHROCYTE CAI AND CAII ISOENZYMES IN HYPOXEMIC AND ANEMIC FETUSES

Objectives: The aims of the present study are (1) to determine the ery throcyte CAI and CAII concentrations in SGA and anemic fetuses and to compare them with normal levels, and (2) to examine whether there is a ny correlation between fetal hypoxia or anemia and isoenzyme concentra tions. Methods: Human erythrocyte CAI and CAII concentrations were mea sured in SGA (n = 25) and anemic (n = 32) fetuses (20-36 weeks' gestat ion), using enzyme-linked immunosorbent assays (ELISA). The blood gase s and pH were measured with an ABL-2c blood gas analyzer. Results and conclusion: In the group of SGA fetuses, there was a tendency for CAI and CAII to be higher than for normal fetuses. The CAI/CAII ratio was also significantly higher than the normal ratio. There were significan t correlations between blood Delta pH and Delta CAI, Delta CAII, or De lta CAI/CAII ratio in this group of fetuses. The levels of CAI, CAII, and CAI/CAII ratio were the same as for normal fetuses in the group of anemic fetuses from red cell isoimmunized pregnancies before their fi rst intrauterine blood transfusion. However, in the group of anemic fe tuses after their first blood transfusion, the levels of both isoenzym es were significantly higher than the normal blood levels. Within the latter group there was a significant negative correlation between the Delta CAI and the percentage of fetal erythrocytes in the circulation.