A systematic review of methods to measure menstrual blood loss

Abstract

Background: Since the publication over 50 years ago of the alkaline hematin method for quantifying menstrual blood loss (MBL) many new approaches have been developed to assess MBL. The aim of this systematic review is to determine for methods of measuring MBL: ability to distinguish between normal and heavy menstrual bleeding (HMB); practicalities and limitations in the research setting; and suitability for diagnosing HMB in routine clinical practice.

Methods: Embase®™, MEDLINE®, and ClinicalTrials.gov were screened for studies on the development/validation of MBL assessment methods in women with self-perceived HMB, actual HMB or uterine fibroids, or patients undergoing treatment for HMB. Studies using simulated menstrual fluid and those that included women with normal MBL as controls were also eligible for inclusion. Extracted data included study population, results of validation, and advantages/disadvantages of the technique.

Results: Seventy-one studies fulfilled the inclusion criteria. The sensitivity and/or specificity of diagnosing HMB were calculated in 16 studies of methods involving self-perception of MBL (11 pictorial), and in one analysis of the menstrual-fluid-loss (MFL) method; in 13 of these studies the comparator was the gold standard alkaline hematin technique. Sensitivity and specificity values by method were, respectively: MFL model, 89, 98%; pictorial blood loss assessment chart (PBAC), 58-99%, 7.5-89%; menstrual pictogram, 82-96%, 88-94%; models/questionnaires, 59-87%, 62-86%, and complaint of HMB, 74, 74%. The power of methods to identify HMB was also assessed using other analyses such as comparison of average measurements: statistical significance was reported for the PBAC, MFL, subjective complaint, and six questionnaires. In addition, PBAC scores, menstrual pictogram volumes, MFL, pad/tampon count, iron loss, and output from three questionnaires correlated significantly with values from a reference method in at least one study. In general, pictorial methods have been more comprehensively validated than questionnaires and models.

Conclusions: Every method to assess MBL has limitations. Pictorial methods strike a good balance between ease of use and validated accuracy of MBL determination, and could complement assessment of HMB using quality of life (QoL) in the clinical and research setting.

Trial registration: PRISMA registration number: CRD42016032956 .

Keywords: Alkaline haematin; Alkaline hematin; HMB; Heavy menstrual bleeding; MBL; Menorrhagia; Menstrual blood loss; Menstrual pictogram; PBAC; Pictorial blood loss assessment chart.

Fig. 1

Systematic search and selection process. ^aSee Additional file 1 for search terms. ^bSee Additional file 2 for search terms

Fig. 2

a Representation of the original menstrual pictogram. Reprinted from Fertility and Sterility, 76, Wyatt KM et al., Determination of total menstrual blood loss, pp125–31, Copyright 2001, with permission from Elsevier [32]. b A modified version of the menstrual pictogram. Larsen L et al., Reproductive Sciences, 20 (6), pp680–7, Copyright © 2013, Reprinted by permission of SAGE publications [26]. c The menstrual pictogram validated for use with towels containing superabsorbent polymers. Reprinted from Fertility and Sterility, 101, Magnay, JL et al., Validation of a new menstrual pictogram (superabsorbent polymer-c version) for use with ultraslim towels that contain superabsorbent polymers, pp515–21, Copyright 2014, with permission from Elsevier [27]