Iron deficiency in the perinatal period should be taken seriously Anemia is a relatively common problem, with a high prevalence of anemia during pregnancy. 40% of maternal deaths are related to anemia, and about 100,000 maternal deaths are due to iron deficiency anemia each year worldwide. In the world, the prevalence of anemia in pregnant women is 35%-75% in developing countries, 18% in developed countries and 22.5% in China. 90% or more are iron deficiency anemia (IDA). The danger of iron deficiency cannot be ignored. Iron deficiency anemia during pregnancy affects the immediate and long term health of the newborn. For the mother, it can lead to decreased physical and mental capacity, inhibit lactation, become less tolerant to blood loss, prone to shock, and affect the cardiovascular system; for the fetus, it can lead to premature birth, increased mortality, delayed brain development, hearing impairment, and cognitive and behavioral problems in childhood. The effects of iron deficiency on infertility Iron regulates ovarian function, and iron supplementation increases the success rate of pregnancy. Iron deficiency is associated with early menopause and an increased incidence of infertility. Effects of iron deficiency on pregnancy outcome Iron deficiency affects the function of proteases that use iron as a complex factor, and changes in cytokine activity hinder embryo implantation and embryonic cell differentiation; iron deficiency is strongly associated with bacterial vaginosis (BV) in early pregnancy, which in turn is strongly associated with spontaneous abortion, preterm delivery, and premature rupture of membranes; iron deficiency increases placental secretion of inflammatory factors; iron deficiency and anemia can cause maternal and fetal Iron deficiency and anemia can cause stress response and release of adrenocorticotropic hormones in pregnant women and fetuses. What is combined anemia of pregnancy and iron deficiency anemia Definition of combined anemia of pregnancy: Chinese guidelines recommend combined anemia of pregnancy as Hb concentration <110 g/L during pregnancy. According to the degree of anemia, it can be classified as mild anemia 100-109 g/L, moderate anemia 70-99 g/L, severe anemia 40-69 g/L, and very severe anemia <40 g/L. The most common are mild and moderate anemia, while severe and very severe anemia are mild and moderate anemia. The most common are mild and moderate anemia, while severe and very severe anemia are still relatively rare in obstetrics. There are more causes of iron deficiency anemia 1. chronic blood loss diseases, including peptic ulcer, urinary tract blood loss, excessive menstrual flow; 2. chronic kidney disease, including pre-dialysis patients, hemodialysis patients; 3. oncological diseases; cardiovascular diseases; 4. rheumatic diseases with abnormal iron metabolism; 5. most of the ischemia in surgical patients and obstetric patients is not due to these above factors, but to the increased need of iron. Iron deficiency anemia is the most common complication during pregnancy. The incidence of iron deficiency in women of childbearing age is as high as 20.04% (with wide local variations). The incidence of serum iron deficiency during pregnancy increases gradually with the week of gestation of the consultation, from 7.09% in early pregnancy to 20% in middle pregnancy and 57.14% in late pregnancy. In the diagnosis of iron deficiency anemia, the indicators reserve iron, transport iron and erythrocyte iron are referred to. Guidelines recommend that iron deficiency is defined as serum ferritin concentration <20 ug/L. Iron deficiency anemia in pregnancy is defined as anemia due to iron deficiency in pregnancy with Hb concentration <110 g/L. Principles of iron supplementation in pregnancy Iron deficiency in pregnancy is prevalent and the main treatment for iron deficiency anemia is iron supplementation. It is often recommended that iron should be routinely supplemented after 16 weeks of pregnancy until 3 months after delivery to prevent the occurrence of anemia and to ensure the health of mother and fetus. Almost all trace elements in pregnancy supplementation except iron can be supplemented in usual food. The doses of iron commonly used clinically for treatment are safe. When iron therapy is not effective, the reasons should be analyzed and treated separately.