Background: Menstrual blood loss (MBL) has been shown to be an important determinant in iron status, work performance and well-being. Several methods have been developed to estimate MBL, the standard quantitative method however has limited application in clinical practice as it is expensive and requires women to collect, store and submit their sanitary products for analysis. We therefore aimed to develop a MBL-score based on a questionnaire, and to validate it by several hematological and biochemical parameters in women of childbearing age.
Methods: A total of 165 healthy young women were recruited. Hematological (hematocrit, hemoglobin, erythrocyte, leucocyte and platelet counts) and iron status (serum iron, serum ferritin, serum transferrin, and total iron binding capacity) parameters were analyzed at baseline. Women were asked to fulfill two gynecological questionnaires: a general questionnaire, to inform about the volunteer's general menstrual characteristics; and a MBL questionnaire, to provide details of the duration of menstruation, number of heavy blood loss days, and number and type of pads and/or tampons used during the heaviest bleeding day, for all consecutive menstrual periods during 16 weeks. A MBL-score was calculated for each period and women, and its reliability determined by the Cronbach's alpha coefficient. Pearson's linear correlation tests were performed between blood parameters and the MBL-score. Two clusters were formed according the MBL-score (cluster 1: low MBL and cluster 2: high MBL).
Results: Significant higher MBL-score was observed in women who reported having a history of anemia (p = 0.015), staining the bed at night during menstruation (p < 0.001) and suffering inter-menstrual blood loss (p = 0.044), compared to those who did not. Women who used hormonal contraceptives presented lower MBL-scores than the others (p = 0.004). The MBL-score was negatively associated with log-ferritin (p = 0.006) and platelet count (p = 0.011). Women in cluster 1 presented higher ferritin (p = 0.043) than women in cluster 2.
Conclusions: We developed an easy and practical method for estimating menstrual blood loss based on a score calculated from a questionnaire in healthy women at childbearing age. The MBL-score is highly reliable and reflects menstrual blood loss validated by hematological and biochemical parameters.