A new and simple method of measuring menstrual blood loss.

: Although it is difficult for women to make reliable judgments about their menstrual blood loss, the direct measurement of such blood loss is useful in diagnosis and in evaluation of therapy. We developed a new and simple procedure for measuring blood on sanitary materials. The procedure is a modification of previous alkaline hematin methods but overcomes some of their major drawbacks. The method involves the separate extraction of blood using a detergent solution and color development of sample aliquots with sodium carbonate. The standard curves obtained for four products tested--regular maxi pads, thin maxi pads and two brands of tampons--were significantly linear over the range of 1-10 mL of blood. The extraction efficiency varied with the four products; tampons exhibited the highest extraction efficiency and thin maxi pads the lowest. Blood loss in normally menstruating women was estimated to be 41.8 +/- 3.9 mL, which correlates well with other estimates reported. Furthermore, the procedure can be used to measure both very low and very concentrated levels of blood on pads or tampons and thus can be used to assess both functional and dysfunctional uterine bleeding.