Efficacy of the high molecular weight fraction of plasma for the maintenance of pregnancy associated with thrombotic thrombocytopenic purpura.

We have investigated the methods for the maintenance of a pregnancy in a patient with thrombotic thrombocytopenic purpura (TTP), said condition, since 1984, having been controlled by a plasma infusion every 3 to 4 weeks. In a preliminary trial it was confirmed that an infusion of the high molecular weight fraction (HMW-F) of plasma, separated by an Evaflux 2A fractionator, improved the patient's thrombocytopenia as the plasma infusion, and maintained its beneficial effect for about 2 weeks during early pregnancy. Though an occurrence of a toxemia-like syndrome responded to repeated plasma infusion, the dose of plasma required to improve the thrombocytopenia gradually increased and reached 5,040 ml by the 20th week of pregnancy. Thus, instead of periodic infusions of whole plasma, periodic infusions of the HMW-F of plasma were used. Under this regimen the platelet count remained above 10.0 x 10(4)/microliters during late pregnancy, and the total dose (2,600 ml) of HMW-F of plasma that was administered until delivery at full term was less than the dosage of whole plasma that was used during early pregnancy. In this manner we were able to obtain a healthy baby by controlling the patient's TTP during pregnancy. This method of preventing thrombocytopenia appears to be safer with respect to volume loading during pregnancy in the TTP patient.