The semi-quantitative assessment of menstrual flow in relation to clinical and hematological parameters

Abstract

The hemostasis of menstruation has not been extensively studied particularly since the development of laboratory tests for von Willebrand factor, a glycoprotein that plays a critical role platelet aggregation. Objective: To determine the relationship of menstrual flow to clinical and hematological parameters. Methods: We studied 155 (56 blood type O/99 blood type non-O) normal female volunteers that met the following criteria: age 12–50; not taking an oral contraceptive, estrogen, or Coumadin; not pregnant; regular periods. A questionnaire was administered regarding the patient’s medical history. A pictorial chart score of menstrual blood flow was obtained using standard tampons/pads for all participants; this semi-objective measure has previously been validated to be diagnostic of menorrhagia at a score of >185. Menstrual coagulation sampling was within the first 3 days of the cycle. We then analyzed by multiple linear regression analysis the pictorial chart score assuming a log-normal distribution as a dependent variable with the following clinical and laboratory parameters as independent variables. Results: The mean age was 35.7 ± 7.4 years. The mean pictorial chart score was 119.1 ± 76.3. ∗ Independent Variable With Pictorial Chart Score as Dependent Variable Parameter Estimate (slope) P Value (two-sided) Age 0.007 .2 Number of prior births 0.16 .02 Blood group type −0.06 .3 Hematocrit −0.01 .3 Factor VIII activity 0.002 .1 von Willebrand factor activity (ristocetin cofactor) 0.001 .3 von Willebrand factor antigen −.003 0.04 ∗ ∗ P value is one-sided (an inverse association was hypothesized). Conclusion: A history of prior births and laboratory evidence of a low von Willebrand factor antigen appear to predict for increased menstrual flow; studies are ongoing in applying these parameters in women presenting with menorrhagia.