OBJECTIVE: To examine the relationship between total fluid volume at menstr
uation and the volume of blood loss, and to assess the feasibility of using
total fluid volume to estimate menstrual blood loss.
METHODS: Fifty-three women were studied over two menstrual periods each. He
moglobin in menstrual pads and tampons was measured using the alkaline hema
tin technique; total menstrual fluid volume was simultaneously measured usi
ng a weighing technique and meticulous care to avoid evaporation.
RESULTS: Despite period-to-period change in measured total menstrual fluid
and menstrual blood loss volumes, there was a significant correlation betwe
en total fluid volume and blood loss (r=.93, P<.001). Blood comprised 48% o
f total menstrual flow for women with moderately heavy blood loss (>60 mL)
and 50% for women with excessive blood loss (>100 mL). Regression estimatio
n of blood loss from total fluid volume was reasonably accurate. For clinic
al purposes, estimated blood volumes correctly classified 98% of periods in
terms of actual blood loss as normal (<60 mL blood), moderately heavy (60-
100 mL), or excessive (>100 mL).
CONCLUSION: If total fluid volume is measured carefully, the estimate of ac
tual blood loss is sufficiently accurate for clinical purposes. This simple
technique has considerable clinical potential, and inexpensive commercial
packs for this purpose could easily be developed. (Obstet Gynecol 2001;98:8
06-14. (C) 2001 by the American College of Obstetricians and Gynecologists)
.