all in the name of Rutherford's messed up, evil blood doctrine!!
History of doctrine[edit]
From 1931,[62] when the name "Jehovah's witnesses" was adopted, Watch Tower Society publications maintained the view of Society founder Charles Taze Russell that the reference to abstaining from the eating of blood in the Apostolic Decree of Acts 15:19–29 was a "suggestion" to be given to Gentile converts.[63][64] Watch Tower publications during the presidency of Joseph Franklin Rutherford commended the commercial and emergency uses of blood.[65][66] ...
In 1944, with the Watch Tower Society under the administration of president Nathan Homer Knorr, The Watchtower asserted that the decrees contained in Genesis 9:4 and Leviticus 17:10–14 forbade the eating or drinking of blood in biblical times "whether by transfusion or by the mouth" and that this applied "in a spiritual way to the consecrated persons of good-will today, otherwise known as 'Jonadabs' of the Lord's 'other sheep'."[70]
https://en.wikipedia.org/wiki/Jehovah%27s_Witnesses_and_blood_transfusions (gov. website)
Blood transfusions
Originally Allowed. Blood transfusions and donating blood for transfusion is commended (Golden Age 1925 July 29 p.683, Golden Age 1929 May 1 p.502, Consolation 1940 December 25 p.19)
1945 - Forbidden. Blood transfusions first stated as wrong (Watchtower 1945 July 1 p.198-201)
https://www.jwfacts.com/watchtower/blood-transfusions.php