glad your surgery went well.  I have had this same question myself in relation to the levels of measurement for male RBC and hematocrit .. very different for men than women. and some argue that a female range is lower because of the "shark week"  yet i think if that were the case then the range would be different for post menapausal women, which it is not.

so as far as blood count on labs-- and a "female born" vascular system  is it really safe to have such think blood volume that the testo gives?   does our system expand and adapt?  or are the numbers just skew. ?  i had a buddy that had been on t for 4 yrs and had to stop  because of an enlarged heart.. but who knows  that may have been related to other things-..           we need good research for us 

The iron lost to (normal) menstruation is tiny. 


This question is kinda like eGFR on a CMP.   

Lemme bring you up to speed.

GFR is glomerular filtration rate, how quickly fluid is passing from your bloodstream into your kidneys.  (Nearly all of this filtrate is reabsorbed, the rest becomes urine.)  The "e" means "estimated."  And a CMP is a comprehensive metabolic panel, a frequently-used set of blood tests. 

GFR can be measured by injecting inulin into the blood, waiting, and measuring how much is left in the blood vs how much ends up in urine.  This works because inulin (a non-toxic plant product) isn't reabsorbed by the kidneys.  But, this test is invasive (two blood draws, an injection, and urine collection) and requires waiting.

It can be estimated with one sample by comparing creatinine (not reabsorbed) to urea (reabsorbed) and guessing how quickly the patient's body produces both.  This guess depends on age, sex, and race.  The lab order specifies age and sex, but not race, so the report usually gives both African and non-African estimates.  Mixed-race?  Lol-who-knows.

(Not only that, but eGFR doesn't give meaningful numbers for healthy kidneys, just a result of "healthy, probably.")

Medicine is a really inexact science.  Sometimes a patient's sex is informative.  Sometimes, it's misleading.  People with intersex conditions, or who have started HRT, or both?  There just isn't the data to say.