Donation of blood by the pregnant patient for autologous transfusion.

A study was conducted to determine the safety and utility of autologous blood donation in third trimester pregnancy. Thirty-seven obstetric patients, 32 with an obstetric risk factor, donated an average of 485 ml of blood. Twenty-one of the 37 patients were expected to undergo cesarean section. Nonstress testing was performed before and after phlebotomy. Continuous fetal heart rate monitoring was maintained throughout the donation, which lasted an average of 9 minutes. All nonstress test results were normal before and after the phlebotomy except in one case. All fetal heart rates remained stable during phlebotomy and premature labor was not precipitated. All fetal outcomes were normal. One patient delivered on the day of phlebotomy, 6 hours after the procedure. Only one of the autologous units was used, in a patient who had a pelvic infection and moderate anemia. The incidence of primary cesarean section was 35%. Phlebotomy of the mother appears to be safe for the fetus at term. Further investigation is needed to determine the safety of removal of more than 1 unit of blood and blood donation at earlier gestational ages.

The failure of postinjection Rh immune globulin titers to detect large fetal-maternal hemorrhages.

The inadequacy of current testing methods for fetal-maternal hemorrhage (FMH) had led to the use of postinjection titers of Rh immune globulin (RhIg) to assess large FMH. The authors have studied the titers of 30 RhIg recipients who received 300 micrograms of RhIg. The 48-hour postinjection titer was compared with the size of bleed as measured by Du testing and the enzyme-linked antiglobulin test (ELAT). Patients had less than 30 mL FMH suggested by negative Du and immune rosette tests. The postinjection titer of RhIg ranged from 0 to 32 when tested by saline-antiglobulin technics. When the size of the bleed was compared with the titer, no correlation could be found. The authors believe that postinjection titers of RhIg should not be used to detect a large FMH.

Comparison of antibody elution techniques by enzyme-linked antiglobulin test.

The enzyme-linked antiglobulin test was used to determine the percentage of antibody removed from sensitized red cells by five elution methods: Rubin ether, xylene, digitonin-acid, glycine, and heat. Antibodies examined in the study included anti-D, -c, -E, and -K. With two examples of anti-D, more antibody was eluted by the Rubin ether method (45.5% average) than the xylene (38%) or the digitonin acid method (35%) (p less than 0.05); the glycine (8%) and heat method (15%) were less efficient. With one example of anti-E and one example of anti-c, more antibody was eluted by the ether method. The percentage of anti-K recovery, however, was greater with the digitonin acid method (45%) than with the ether (30%). We found the enzyme-linked antiglobulin test method useful in the quantitative evaluation of elution procedures.