Effect of hydatidiform molar vesicular fluid on blood coagulation.

The effect of fluids from both complete and partial hydatidiform moles on blood coagulation was determined. Coagulation was evaluated with use of the one-stage prothrombin time and the activated partial thromboplastin time. These studies demonstrated that the fluids shortened the activated partial thromboplastin time but not the prothrombin time. The use of plasmas deficient in factors V, VIII, IX, and X as substrate showed that the fluids shortened the activated partial thromboplastin time in the presence of plasmas deficient in factors VIII and IX but had no effect on the activated partial thromboplastin time in the presence of plasmas deficient in factors V and X. These data suggest that hydatidiform mole fluids possess procoagulant activity and that the activation of blood coagulation takes place at the level of factor X. These findings may have relevance to the placental and decidual focal necrosis seen in molar pregnancies, especially those of the complete variety.