Validation of a rapid alkaline hematin technique to measure menstrual blood loss on feminine towels containing superabsorbent polymers

Abstract

To validate the semiautomated alkaline hematin technique for rapid measurement of menstrual blood loss on ultrathin sanitary towels with a superabsorbent polymer component. Laboratory study using simulated menstrual fluid (SMF) and Always Ultra Normal, Long, and Night "with wings" sanitary towels. Laboratorium für Klinische Forschung, Germany. None. None. Linearity and blood recovery over a range of SMF volumes applied to towels, the lower limit of reliable detection, and the effect of storing soiled towels for up to 5 weeks at 20°C and 4°C before analysis, were determined. Recovery from 63 SMF samples comprising between 5% to 100% blood and 0.05-35 mL applied volume was compared with duplicates analyzed at Keele Menstrual Disorders Laboratory (manual reference method). Linearity was confirmed, and ≥85% recovery was reproducibly achieved at up to 30 mL applied blood at all tested SMF compositions, except at low volume or high dilution equivalent to <4 mL blood. Samples could be stored for 3 weeks at 4°C without loss of recovery. Linear regression analysis showed good agreement with the reference method. The semiautomated alkaline hematin technique is a reliable method for measuring menstrual blood loss from Always Ultra sanitary towels containing superabsorbent polymers.