The most recent piece of research on actual menstrual blood volume was conducted in 1964, which has left many people without key health information, writes researcher Claire Badenhorst.
Last month, after being in the office for only half a day, I headed home early for the sole reason that I had worn white pants to work and my period had arrived. I felt caught off guard, was unprepared, and so I used a well-executed escape plan to avoid any potential embarrassment. I’m not the only person this has ever happened to. Sometimes we forget it’s coming, other times we underestimate how heavy our flow is. But what is a “normal” flow and how do we know if we have it?
Medically, people who are heavy menstrual bleeders are those who lose more than 80ml of menstrual blood, which is a third of a cup. Most online resources would suggest that normal menstrual blood loss is 2-3 tablespoons (45ml). These measurements are over the entire time that a person is menstruating (in an individual cycle) and not on any single day. In ethnically diverse populations, any research on menstrual blood loss is notably absent.
Heavy menstrual bleeding is known to increase stress, worry, and anxiety; a combination that is not helpful if you have a work deadline. This stress and worry are not because a person has a menstrual bleed, rather it is related to the unexpected arrival or heaviness of this month’s menstrual bleed and if they are prepared for this (eg. mentally checking the number of tampons available in the desk drawer or handbag).
There is still a lingering hesitancy to talk about the menstrual cycle, particularly around periods, “that time of the month”, “the crimson tide”, “shark week”, or [insert your personal euphemism for menstrual bleeding]. In reality, I’m not sure how many people check or are able to gauge tablespoon or cup measures from a tampon, a pad or pair of period underwear.
The most recent piece of research that looked at actual volume measurements of menstrual blood loss and people’s thoughts about how much they thought they lost while menstruating (I lost minimal, moderate, heavy amount this cycle) was last done in 1964. Yes, that is correct, 1964. This research found that 37% of people who medically classified as heavy menstrual bleeders (lost more than 80ml) thought they only lost a moderate/normal amount of blood each cycle, while 4% actually thought their menstrual blood loss was quite minimal. On the other hand, 14% of those who were medically considered to have minimal menstrual blood loss (lost less than 20ml) thought that they were heavy bleeders.
Most of the more recent research on volume and awareness of menstrual blood loss has been based on questionnaires that ask about the occurrence of leakage, the use of double sanitary items, and how often a person changes their sanitary items. Those who select yes to two of these questions are then considered to be heavy menstrual bleeders. The problem is: none of these questions factor in an individual’s anatomy, physical activity levels, what sanitary products (absorbency level) they are using, or even their personal hygiene preferences, which could all dramatically influence their responses to the questionnaire. If our understanding of menstrual blood loss is based on the available research, it is safe to say that our understanding may be out of date and quite low quality.
Increasing awareness of menstrual blood loss is not only beneficial for reducing stress and anxiety each month but could give people key insights into their health. For example, heavy bleeders are 5-6 times more likely to be iron deficient and suffer from fatigue that affects their work productivity, physical activity levels and daily life. But which individuals are more likely to be heavy menstrual bleeders or what variations in menstrual blood loss are “normal” is still an ongoing area of research.
Research on the influence of the menstrual cycle on health, physical activity and wellbeing has dramatically increased in the last decade in an attempt to rebalance the historic deficit and increase knowledge and understanding. But it is worth remembering that biologically female participants have previously only made up 34% of everyday health and sports research (outside of fertility research). With only 6% of historical research being “female-specific”.
Within New Zealand, Health Research Council funding is supporting research projects that are addressing this research deficit, with results that could help many gain an understanding of their menstrual cycle, their risk of iron deficiency and when they may need to seek medical support. On any day, more than 300 million people worldwide are menstruating. It’s time we got curious about understanding all aspects of the menstrual cycle. Doing so would support those who menstruate in improving personal and menstrual health literacy, and have greater respect and understanding for their body, health, and well-being.