Infantile physiological anemia is a kind of anemia caused by the destruction of red blood cells in the body and the reduction of hemoglobin after birth, which is a normal physiological phenomenon that must occur during the growth and development of every infant, so it is called infantile physiological anemia. Why does red blood cell destruction occur in infants after birth? Before the baby is born, it is called a fetus. The fetus in the mother’s body has no lung respiratory movement, which means that it is impossible to inhale oxygen and expel carbon dioxide through the lungs, so where does the fetus get the oxygen needed by the cells of the body? First of all, the mother inhales oxygen through lung respiration, and the hemoglobin of the mother’s red blood cells brings oxygen to the placenta and passes it to the fetal red blood cells, but the oxygen-carrying capacity of the fetal red blood cells hemoglobin is only half of the oxygen-carrying capacity of the mother’s red blood cells hemoglobin, so the fetal hematopoietic organs must produce more cells and hemoglobin to carry oxygen in order to meet the needs of fetal growth and development, so the fetal hemoglobin at birth hemoglobin can be as high as 190g/L or more at birth. After birth, the infant’s pulmonary respiratory movement begins, and the oxygen-carrying capacity of the red blood cells increases significantly, so that the fetus no longer needs as many red blood cells, and the body “instructs” the bone marrow to reduce the production of red blood cells; and at this time, the red blood cells produced during the fetal period also begin to destroy; in addition, the 3 months after birth is the fastest growing period for infants, and the increase in blood fluid The increase in blood volume is greater than the increase in red blood cell production, and the original concentration of red blood cells is diluted. The combined result of the above factors is that hemoglobin gradually decreases within one week after birth and generally stops only after 8 weeks, and can drop to 90-110 g/L in 2-3 months after birth. this transient state of anemia caused by normal physiological changes is called physiological anemia. In the process of hemoglobin decline, the body “instructs” the bone marrow to gradually increase its hematopoietic capacity, and the hemoglobin generally rises to normal levels of 120-160 g/L around the age of half a year. Before the birth of a fetus, the mother gives him/her a special gift. -blood-forming materials are stored in the fetus, and these materials ensure the fetus’ blood-forming needs for at least 3 months after birth. Although every baby is born with physiological anemia, in general, the hemoglobin of full-term newborns rarely drops below 90 g/L. However, the hemoglobin of preterm babies can drop by 70-90 g/L 3-6 weeks after birth, due to the fact that preterm babies receive less hematopoietic material from their mothers, coupled with the fact that preterm babies grow faster than full-term babies after birth and have a relatively greater increase in blood fluid volume and greater dilution of red blood cell concentration. This is due to the fact that preterm infants receive less hematopoietic material from their mothers, and that they grow faster than full-term infants after birth, resulting in a relatively greater increase in blood fluid volume and greater dilution of red blood cells. Physiological anemia is a normal phenomenon that occurs during the growth and development of infants, so no treatment is necessary. However, care should be taken that the food fed is rich in the substances needed for hematopoiesis.