Red blood cell order to stimulate production of red blood cells. Both practices are banned by the World Anti-Doping Agency. The first person to describe red blood cells was the young Dutch biologist Jan Swammerdam, who had used an early microscope in 1658 to study the blood of a frog. Unaware of this work, Anton van Leeuwenhoek provided another microscopic description in 1674, this time providing a more precise description of red blood cells, even approximating their size, "25,000 times smaller than a fine grain of sand". In 1901, Karl Landsteiner published his discovery of the three main blood groups—A, B, and C
Neonatal red cell transfusion Neonatal red cell transfusion Neonates are defined as babies up to 28 days after birth. Most extremely preterm babies (less than 28 weeks) require at least one red cell transfusion, this is partly due to the amount of blood removed with blood samples compared to the baby's total blood volume (iatrogenic anemia) and partly due to anemia of prematurity. Most transfusions are given as small volume top-up transfusions to increase the baby's hemoglobin above a certain pre-defined level, or because the baby is unwell due to the anemia. Possible side-effects of anemia in babies can be poor growth, lethargy and