Table 2.

Additional advantages and disadvantages of methods to measure menstrual blood loss

Method	Advantages	Disadvantages
Alkaline hematin	• “Gold standard” in terms of accuracy • Has undergone considerable development to improve rapidity; validated for selected SAP-c towels • Well suited to research setting • Best used in conjunction with a pictorial method and a diary	• Requires calibration curves for each product and does not take extraneous blood loss into account • Patients in the clinical setting may be deterred by having to collect, store, and send sanitary products for analysis
Gynaeseal/Mooncup	• Requires few changes per day	• Subject to leakage during collection and therefore unsuitable for either clinical or research purposes
MFL	• Simple • Can be used to measure effect of medical intervention	• Requires collection of used sanitary products and pre- and post-use weighing • Sanitary item must be stored in a sealed container before weighing to minimize fluid evaporation
Duration of period	• Simple and easy	• Participants must record/recall results
Counts of pads	• Simple and easy	• Participants must record/recall results • Frequency of changing pads can be influenced by many variables
Measurement of iron/labelled red blood cells	• Most methods are accurate	• Technically challenging to perform, requires specialist equipment, and is therefore most suited to research
PBAC	• Quick and simple • Has undergone extensive development; validated for selected SAP-c towels • Suitable for research purposes and has potential value in the clinic	• Only validated for a limited number of current products • Participants must record/recall results
Menstrual pictogram	• Quick and easy • Has undergone development; validated for selected SAP-c towels • Suitable for research purposes and has potential value in the clinic • Differentiates between absorbency ratings of sanitary items	• Only validated for a limited number of current products • Participants must record/recall results
Question-naires	• Many available, ranging in complexity, with questions relating to MBL, generic or disease-specific QoL, or both	• Poorly validated, with a few exceptions • Participants must record/recall results
Self-perception	• Simple • Useful for clinical assessments	• Does not give precise MBL measure • Participants must record/recall results • Individuals can be poor judges of MBL • Not diagnostic

MBL menstrual blood loss, MFL menstrual fluid loss, PBAC pictorial blood loss assessment chart, QoL quality of life, SAP-c superabsorbent polymer-containing