Final answer:
Newborns are susceptible to anemia due to the transition from fetal to adult hemoglobin, low birth weight, and potential hemolytic disease if the mother is Rh- and the fetus is Rh+, along with immature kidney function and increased iron demand.
Step-by-step explanation:
Newborns are at increased risk for developing anemia for several reasons. One critical factor includes the difference in fetal hemoglobin which binds with oxygen more readily than adult hemoglobin but must switch to adult forms after birth. Newborns with low birth weight, which can stem from maternal undernutrition or intrauterine growth restriction, are more susceptible to anemia.
Moreover, hemolytic disease of the newborn (HDN) can be a specific risk for babies born to mothers with Rh- blood type who carry Rh+ fetuses, especially during second or subsequent pregnancies due to the formation of anti-D antibodies that can attack the fetal red blood cells.
Other contributing factors include the immature and inefficient state of the neonatal kidneys, an increased demand for iron during rapid growth, poor iron stores at birth in cases of premature birth or twin pregnancies, and pathological blood loss.