An ultrastructural study of menstrual blood in normal menstruation and dysfunctional uterine bleeding.

Menstrual fluid was obtained from the uterine cavity and vagina in 20 women within the first 48 h of menstruation. Ten of the women had normal menstrual cycles and blood loss and ten were patients with dysfunctional uterine bleeding. The menstrual samples were examined by electron microscopy for the presence of fibrin and platelets and nearly all were found to contain both fibrin and aggregating platelets. By a simple quantitative system no differences in fibrin and platelet content were found between samples collected from the uterine cavity or the vagina. Likewise no difference was found in the morphology of fibrin and platelets between women with normal menstrual loss and patients with dysfunctional uterine bleeding.