First, early pregnancy Early pregnancy refers to the third month of pregnancy, that is, before 12 weeks of pregnancy. Most pregnant women do not have any reaction in early pregnancy, but the neural tube, limbs and eyes of the fetus begin to differentiate in this period, and at this time, once encountered with harmful substances, the cells of these tissues and organs stop developing and become mutilated, thus resulting in malformations. Therefore, toxic and harmful substances, such as chemical pesticides, heavy metals lead, methylmercury and radioactive substances should be avoided at this stage. Keep a certain distance when listening to the stereo and watching TV, use computers and cell phones as little as possible, and avoid drinking strong tea, strong coffee and cola-type beverages; the ideal beverage for pregnant women is plain water. A lot of smoking by pregnant women can cause fetal malformation, so pregnant women should quit smoking and drinking. Viruses and drugs may affect the development of the fetus, so pregnant women should not abuse drugs during pregnancy, but not no drugs, most of the drugs are still safe for the fetus, so pregnant women who are sick still need to use drugs correctly under the guidance of the doctor. Early pregnancy, the fetus does not need much nutrition, in the diet should choose light and tasty and easy to digest food, at this time can eat as much as you can eat, do not have to mind too much about the problem of nutritional deficiencies, but you should start from this time to cultivate good eating habits, not picky about what they eat, do not favoritism, to maintain a balanced nutrition. In addition, you should ensure sufficient oxygen, take a walk outdoors for one hour every day, keep your spirit happy, pay attention to rest, and ensure enough sleep. In order to prevent neural tube malformation, early pregnancy can be appropriate supplementation of folic acid, the general requirements of the daily dose of folic acid 5mg, but folic acid supplementation need to pay attention to the following points: ① ever delivered a baby with neural tube defects in women planning to get pregnant on the taking of folic acid, double the dosage; ② folic acid supplementation of excessive zinc absorption, affecting fetal development; ③ certain medications affect the metabolism of folic acid, planning to get pregnant before you should discontinue use. Should be discontinued before planning to get pregnant. Second, the mid-pregnancy The mid-pregnancy refers to the pregnancy 4 to 7 months, that is, after 13 to 27 weeks of pregnancy. At this time is the fetal cell differentiation after the beginning of the formation of major organs and internal organs, such as the heart, kidneys, limbs stage. This is a process of differentiation, so a lot of nutrients are needed during this period, and protein, iron, calcium and other components are in higher demand than usual at this stage. Daily iron supplements are recommended, as well as adjusting the dietary structure to appropriately increase animal blood, lean meat, eggs and a variety of vegetables. As the role of vitamin and calcium is to promote bone growth, so vitamin D is four times more than the normal demand, but the calories only need to increase by fifty percent, so this period to eat more calcium-containing food, less sugary food. Because too much salt absorption will cause swelling and gestosis in late pregnancy, so you should eat less food containing more salt. In addition, due to the increase in the amount of food is easy to constipation, in order to prevent constipation should eat more coarse grains and coarse fiber vegetables, drink more water, more activities. Third, late pregnancy late pregnancy refers to 8 to 10 months of pregnancy, that is, after 28 weeks of pregnancy. At this time to guard against pregnancy toxicity, mainly manifested as swelling, proteinuria, hypertension, weight control and enough sleep is an effective measure to prevent these symptoms. In addition, fetal movement can be used to monitor the fetus. If the number of fetal movements is less than 3 per hour or drops by more than half compared to the previous day, it means that the fetus is suffering from hypoxia in the uterus, and it should be consulted in the hospital. In order to prevent nipple 鈪 crack when breastfeeding after delivery, scrub the nipple should be coated with some grease. This period of nutritional needs to increase again, the choice of food should ensure that the higher nutritional value of protein, food containing minerals and vitamins and smaller nutrients. As the abdomen expands and the digestive function continues to decline, constipation is more likely to occur, so you should eat more potatoes, seaweed and fiber-rich vegetables, to control fat and starchy and salt-containing foods, so as not to overfat the fetus to the delivery of the difficulty to be appropriate exercise in order to help a smooth delivery. In the whole process of pregnancy, a good state of mind plays a vital role for the fetus, the nutrients needed for the growth and development of the fetus are provided by the mother’s blood circulation through the placenta, and the mother’s adverse emotional changes will affect the intake of nutrients, hormone secretion, and the chemical composition of the blood. Therefore, in the course of pregnancy, pregnant women should endeavor to maintain a good mood, often go out for a walk to relax and listen to more light music.