The blood group may be included on identification tags or on tattoos worn by military personnel, in case they should need an emergency blood transfusion. Frontline German Waffen-SS had blood group tattoos during World War II. Rare blood types can cause supply problems for blood banks and hospitals. For example, Duffy-negative blood occurs much more frequently in people of African origin, and the rarity of this blood type in the rest of the population can result in a shortage of Duffy-negative blood for these patients. Similarly, for RhD negative people there is a risk associated with travelling to parts of the world where supplies of RhD negative blood are rare, particularly East Asia, where blood services may endeavor to encourage Westerners to donate blood. Hemolytic disease of the newborn (HDN)
A pregnant woman may carry a fetus with a blood type which is different from her own. Typically, this is an issue if a Rh- mother has a child with a Rh+ father, and the fetus ends up being Rh+ like the father. In those cases, the mother can make IgG blood group antibodies. This can happen if some of the fetus blood cells pass into the mothers blood circulation (e.g. a small fetomaternal hemorrhage at the time of childbirth or obstetric intervention), or sometimes after a therapeutic blood transfusion. This can cause Rh disease or other forms of hemolytic disease of the newborn (HDN) in the current pregnancy and/or subsequent pregnancies. Sometimes this is lethal for the fetus; in these cases it is called hydrops fetalis.
In medicine, pleocytosis (or pleiocytosis) is an increased cell count (from Greek pleion, "more"), particularly an increase in white blood cell count, in a bodily fluid, such as cerebrospinal fluid. It is often defined specifically as an increased white blood cell count in cerebrospinal fluid.Increased white blood cell count in the blood is called leukocytosis. == References ==