As we all know, expectant mothers must consume rich and balanced diversified foods to meet all the 40 nutrients needed for fetal growth and development. Among them, 6 kinds of nutrients are very important for fetal intelligence development. Mothers should pay extra attention during pregnancy to make their brains smarter.

　　1. Protein

　　protein is the most important nutrient required by the human body. From a chemical perspective, in addition to water, the main component of the fetal body is protein. Protein is the basic component of brain cells (and other cells). The stage of the fastest growth of the number of fetal brain cells is from 30 weeks of pregnancy to 1 year of age after birth. In fact, three quarters of adult brain cells are formed during the fetal period. It can be said that the fetal period (and one year after birth) is the basis of intellectual development. If the intake of protein during fetal period is insufficient, the number of fetal brain cell proliferation is insufficient, and cannot be compensated after birth and growing up, irreversible, leaving a lifetime regret.

　　Intake of sufficient protein is the first important dietary principle during pregnancy. According to the recommendations of the Chinese Nutrition Society, during the second and third trimesters of pregnancy every day, 15 and 20 grams of protein should be eaten every day than when not pregnant, reaching 80 and 85 grams, respectively. The best sources of dietary protein are animal foods such as milk, eggs, fish and meat. Their protein (amino acid) composition is close to the human body and has a high nutritional value. During the second and third trimesters of pregnancy, daily intake of 300-500 grams of milk, 50 grams of eggs, 100 grams of livestock, poultry and meat, 100-150 grams of fish and seafood.

　　Comparatively speaking, plant foods such as grains, potatoes, vegetables and fruits contain less protein, and its protein (amino acid) composition is far from the human body, and its nutritional value is low, not protein. Good source. But soybeans (the most common soybeans) in plants are unique, and their protein (amino acid) composition happens to be closer to humans, and their nutritional value is also very high. During the second and third trimesters of pregnancy, 40 grams of soybeans or equivalent soybean products should be ingested every day, such as tofu (200 grams), dried tofu (80 grams), yuba (30 grams), tofu brain (700 grams), etc.

　　2. Phospholipids

　　phospholipids are a type of lipid compounds with complex molecular structure and containing phosphoric acid. Lecithin, cephalin and inositol are common. Phospholipids, etc. They are all important components that constitute cell membranes, mitochondrial membranes and other biological membranes. Brain nerve cells are no exception, and their cell membranes use phospholipids as the main framework. Lecithin molecules contain choline, which is the raw material for the synthesis of acetylcholine, and acetylcholine is a carrier for transmitting information between various nerve cells.

　　Although the body''s phospholipids can be synthesized on their own and do not completely depend on food supply, it is still beneficial to take in abundant phospholipids in the diet. And foods rich in phospholipids, such as egg yolk, soybeans, lean pork, beef and mutton, are also a good source of important nutrients such as high-quality protein, calcium, iron, vitamin A, and vitamin B family. Common foods with the most abundant phospholipids are egg yolk and soy milk.

　　3.DHA

　　DHA is the abbreviation of fatty acid "docosahexaenoic acid". DHA is the fatty acid found in the human body with the longest carbon chain and the most double bonds. In the human body or in food, DHA often coexists with EPA. The scientific name of EPA is "Eicosapentaenoic Acid". They are all ω-3 polyunsaturated fatty acids.

　　Baby brain contains 60% fat, of which 20% is omega-3 Fatty acids (mainly DHA+EPA). In other words, DHA and EPA are one of the important components of fetal brain tissue. In the second and third trimesters of pregnancy, the rate of division and proliferation of fetal brain cells is very fast, reaching 250,000 per minute. So it is not difficult to understand that DHA is essential for the intelligent development of the fetus. Studies have shown that adequate intake of DHA during pregnancy and lactation has an effect on the baby''s mental, vision and immune system development and long-term cognitive ability.

　　 Therefore, attention should be paid to the intake of DHA from the second trimester. According to the 2008 recommendation of the World Health Organization (WHO) and the United Nations Food and Agriculture Organization (FAO) Joint Fat Experts Committee, pregnant women''s daily intake of DHA+EPA is 300 mg, of which DHA is at least 200 mg.

　　Fish, seafood, egg yolk, seaweed and other foods contain DHA, and other foods contain almost no DHA. Therefore, there should be a certain amount of fish, seafood, egg yolk and seaweed in the diet structure in the second trimester. It is generally recommended to consume 100 grams to 150 grams of fish and seafood, 1 egg yolk (1 egg), and an appropriate amount of seaweed (such as kelp, seaweed, wakame, etc.) during the second and third trimesters of pregnancy.

　　In the body, DHA can also be converted from linolenic acid through a complex metabolic process. Linolenic acid is very high in linseed oil and perilla oil (more than 50%). The content of linolenic acid in other oils such as rapeseed oil, peanut oil, soybean oil and olive oil is very low (1%~8%). Therefore, the fat in the diet structure during the second trimester should include a part of flaxseed oil and/or perilla oil, and 5 to 10 grams per day is suitable.

　　 has to admit that compared with the amount of DHA (recommended) required by pregnant women, the content of DHA in natural foods is obviously too small. Especially pregnant women who cannot guarantee the intake of fish and seafood. At this time, it is beneficial to choose pregnant women''s milk powder supplemented with DHA or fish oil capsules specially supplemented with DHA.

　　4. Iron

　　Iron is a key raw material for the synthesis of hemoglobin. Hemoglobin is the main carrier of oxygen in the blood. The oxygen needed by pregnant women and fetuses must be carried by hemoglobin. When the diet is deficient in iron during pregnancy, hemoglobin synthesis is insufficient, the concentration of hemoglobin decreases, and the ability to carry oxygen is insufficient, so that both pregnant women and fetuses are in a state of "hypoxia"-anemia.

　　 There is no doubt that anemia (hypoxia) will seriously hinder the normal development of the fetus. Especially the fetal brain development. Because brain tissue consumes more oxygen, it is particularly sensitive to hypoxia, and the damage suffered is the earliest and most serious. Anemia during pregnancy and anemia in infants and young children are the most common causes of low IQ in children.

In the second and third trimesters of pregnancy, the iron requirement increases greatly, and 25 mg and 35 mg should be ingested every day. At the same time, most daily diets have low iron content and low absorption rates. Therefore, iron deficiency anemia is one of the most common nutritional deficiencies among pregnant women. In China, an average of at least one in three pregnant women suffers from anemia.

　　Prevention and treatment of iron-deficiency anemia during pregnancy must first choose more foods rich in iron. Animal foods rich in iron include pork liver, pig blood, lean meat, beef, lamb, and fish. These foods not only have high iron content and high absorption rate (10%~20%), but also promote the absorption of iron in other foods. Other iron-rich foods include spinach, celery, cabbage, fresh beans, shepherd''s purse, taro, bean sprouts, laver, kelp, mushrooms, black fungus and other vegetables, as well as jujube, grape, hawthorn, apricot, peach and other fruits. However, the absorption rate of iron in vegetables, fruits, cereals and beans is very low (1% to 5%). To ensure the effective supply of iron, meat, animal blood, internal organs and fish are the best choices. Therefore, it is very important to keep a certain amount of meat and fish in the diet structure during pregnancy. Their role in preventing and treating iron deficiency anemia is almost irreplaceable.

In addition to ingesting foods rich in iron, choosing fortified foods with added iron (such as iron soy sauce, iron milk or milk powder, fortified flour, etc.) is also an important means of preventing and treating iron-deficiency anemia during pregnancy . In addition, if necessary, iron supplements can also be taken by taking iron-containing nutritional supplements.

　　5. Folic acid

　　Folic acid is a vitamin and belongs to a large family of vitamin B. It was isolated from spinach leaves in 1941, hence the name "folic acid". In the body, folic acid can participate in amino acid metabolism, nucleic acid synthesis and protein synthesis.

　　Folic acid plays an important role in the synthesis of nucleic acids (DNA). And those tissues that grow and proliferate rapidly, such as hematopoietic cells, embryonic cells (fetus), etc., the synthesis of nucleic acid (DNA) is very active. Therefore, folic acid deficiency first affects these tissues. Especially in the early stage of embryonic development (1 to 3 weeks after the implantation of the fertilized egg), the lack of folic acid can cause "neural tube malformation", resulting in serious conditions such as "brainless" and "spinal spina bifida" in the fetus. Most of the results are Fetal death. Lack of folic acid during pregnancy can also cause preeclampsia, placental abruption, intrauterine growth retardation, premature delivery, low birth weight infants, megaloblastic anemia, etc.

　　 People pay attention to folic acid intake in early pregnancy, not just to prevent fetal malformation. In recent years, many studies have shown that the lack of folic acid in early pregnancy, even mild deficiency, may not cause severe deformities such as brainless children or spina bifida, but it will still damage the fetal brain development and affect the intelligence level of the fetus after birth. Folic acid is one of the nutrients closely related to fetal brain development.

　　 Therefore, adequate intake of folic acid during early pregnancy is one of the most important health promotion measures. Not only can it effectively prevent neural tube defects, but also reduce the incidence of other deformities and promote fetal brain development. The U.S. Public Health Agency and the Medical Association recommended that women of childbearing age take 400 micrograms (1000 micrograms = 1 milligram) of synthetic folic acid from supplements and fortified foods in 1992 and 1998, respectively. The Ministry of Health of China began to implement a folic acid supplementation project to prevent neural tube defects in 2009, using central government subsidies to provide free supplementation of folic acid to rural women who are preparing for pregnancy throughout the country. Rural women who are planning to get pregnant can receive folic acid supplements at designated institutions for free, 400 micrograms per person per day, from 3 months before pregnancy to 3 months before pregnancy.

　　It must be emphasized that the effect of synthetic folic acid in preventing neural tube defects is more reliable than that in natural food. Folic acid in natural foods is unstable, easily destroyed and lost during cooking and processing, and the presence of folic acid is more complicated (peptidyl polyglutamic acid), not easily absorbed by the small intestine, and the bioavailability is low, 50%. The structure of artificially synthesized folic acid is relatively simple (tallowoyl monoglutamic acid), easy to absorb, and has a high bioavailability of 85%.

　　The timing of taking folic acid is critical. You should start taking folic acid when you are planning to become pregnant, and continue to take it after confirming pregnancy, at least until 12 weeks of pregnancy, if conditions permit, you can take it until the end of pregnancy.

　　According to the recommendations of the Chinese Nutrition Society, as long as the intake of folic acid during pregnancy is not more than 1000 micrograms per day, it is safe, and you don’t have to worry about too much. Taking 400 micrograms of folic acid supplements daily, plus a small amount of folic acid obtained from food, rarely exceeds 1,000 micrograms. So taking 400 micrograms of folic acid supplements every day is safe and effective.

　　 Of course, sufficient natural folic acid in food is also effective. Foods rich in folic acid include animal liver, kidney, green leafy vegetables, beans, peanuts, strawberries, citrus, etc.

　　6. Iodine

　　Iodine is an important trace element and a key raw material for thyroid hormone synthesis. Thyroid hormone is one of the main hormones in the body responsible for metabolism. Thyroid hormone synthesis is reduced, lowering the mother''s metabolism, and therefore reducing the supply of nutrients to the fetus.

　　Before 20 weeks of pregnancy, the thyroid hormones needed by the fetus are provided by the mother. After 20 weeks, it is synthesized by the fetus'' own thyroid. In any case, iodine is required. Iodine deficiency leads to physical and mental developmental disorders of the fetus, which can cause serious consequences, such as dwarf, mental retardation, deafness, etc. Even if mild iodine deficiency does not cause these terrible consequences, the study found that it will also reduce the fetal intelligence score after birth. Iodine is also a nutrient closely related to fetal brain development.

　　Iodine needed during pregnancy can be provided by iodized salt that is now commonly consumed. 200 micrograms of iodine should be ingested every day during the first trimester, which is roughly equivalent to the iodine content in 6, 7 grams of iodized salt.

　　It must be pointed out that under the premise of eating iodized salt, iodine intake of pregnant women is very sufficient. Therefore, pregnant women do not need to deliberately eat more kelp, seaweed, wakame and other foods containing large amounts of iodine. In recent years, studies have pointed out that excessive iodine intake will have a negative impact on health.