How Can One Person's Blood Save 2 Million Babies?

James Harrison, an Australian, holds the world record for blood donations, saving over 2 million lives, mainly newborns. Blood type incompatibility, particularly the Rh factor, can cause complications during pregnancy. Rh-negative mothers risk attacking Rh-positive fetal blood cells, leading to anemia or heart failure. Anti-D immunoglobulin injections, derived from donors like Harrison, prevent these issues by neutralizing Rh-positive cells in the mother's bloodstream, safeguarding the fetus.

What happens when a pregnant woman is Rh-negative and the fetus is Rh-positive?

How does anti-D immunoglobulin help in preventing complications during pregnancy?