Hello,
The first could be logical.
If you read 2006 WT and KM on blood and fraction , you can see that all plasma fraction are authorized
but the plasma is forbidden.
It seem logic ( to me ) to tell that 100 % of Plasma is the same as the plasma not fractionned.
beside plasma , we have all research and medical publication that expose that "all components" of foetus blood
goes to mother's blood , in fact even in case of natural abortion foetus modify the composition of mother's blood !!!
Sorry for non french speaker
https://www.radiofrance.fr/franceinter/podcasts/in-utero
the 3rd seasons speak about "chimera Cells" and "micro-chimerism" ( I don't know if it exists the word in english )
Considering these new biological result , the GB can say "after praying and studying intensively the Scripture we conclude that blood rules in the bible are linked with food rules" and then speaking ( maybe ) about biological results, To avoid the responsability of the errors about blood " we don't know before the result that blood goes from mother to foetus and foetus to mother" even if they know since the explanation about "albumin" ... JW have no memory ....
Best regards
PS : Hope I'm clear with my poor english :)