Physiologic observations of pregnant women undergoing prophylactic erythrocytapheresis for sickle cell disease

Abstract

Five women in the second or early third trimester of pregnancy underwent prophylactic partial red cell exchange by automated erythrocytapheresis for sickle cell disease. The purpose of this pilot study was to characterize the hematologic, hemodynamic, and metabolic changes associated with this procedure. Pretransfusion hematocrit increased 49 percent by 3 to 5 days after the transfusion. Paired observations indicate a 14-percent drop in maternal oxygen consumption. There was a slight tendency for reduced posttransfusion cardiac output that resulted primarily from changes in maternal heart rate and not from changes in stroke volume. Left ventricular contractility also tended to decrease after transfusion. Neither fetal bradycardia nor alteration in the umbilical circulation by Doppler ultrasound was observed during the transfusion procedures. Despite substantial hematologic alterations, this procedure is associated with small or negligible changes in maternal hemodynamic and metabolic function for minimally symptomatic pregnant patients with sickle cell disease.