1. Excessive nutrition. Too much nutritional intake will increase the burden on the body and store too much fat, leading to obesity, coronary heart disease, gestational diabetes, the risk of gestational hypertension syndrome, may also lead to huge children, increasing the likelihood of difficult childbirth. And huge children are prone to hypoglycemia, hypocalcemia, erythrocytosis, etc., and is also a potential factor for obesity, diabetes, cardiovascular disease in adulthood; 2, high-fat diet. Long-term high-fat food will increase the concentration of bile acid and neutral cholesterol in the colon to induce colon cancer; high-fat food can increase the synthesis of prolactin and promote the occurrence of breast cancer; long-term high-fat diet increases the risk of fetal cancer of the reproductive system; 3, away from fat. Lack of fat can lead to fetal weight gain, affecting brain and nervous system development. 4, high protein. High protein diet during pregnancy, excessive protein intake, can affect the appetite of pregnant women, increase the burden on the gastrointestinal tract, affect the intake of other nutrients, may lead to calcium deficiency; the body can produce a large amount of hydrogen sulfide, histamine and other harmful substances, easily cause abdominal distension, loss of appetite, dizziness, fatigue and other phenomena; can cause an increase in nitrogen in the blood; easily lead to increased cholesterol, aggravate the pressure of glomerular filtration of the kidneys . 5, do not eat staple foods. Staple food contains a large number of carbohydrates, mainly to provide energy, maintain blood sugar, staple food eaten too little, prone to hypoglycemia, producing toxic effects on the nervous system ketone bodies; staple food sugars are a multi-carbon sugar, different from the fructose in fruit. Polycarbose is in addition to supplying the body with the necessary energy, it will also promote the generation and activation of some important enzymes in the body, such as liver detoxification mainly by an enzyme called glucuronide, which mostly exists in glycosides or polysaccharides, which are mainly obtained from staple foods. Throughout pregnancy, staple foods are quite important and one should have to ensure an intake of more than four taels of staple foods a day. Rice, noodles and other starch-rich foods can provide carbohydrates, proteins, trace elements and vitamins. Dry, easily digestible staple foods are actually more suitable for pregnant women with pregnancy reactions, 6. Excessive folic acid. It may affect the metabolism of zinc in the body and cause zinc deficiency, resulting in delayed fetal development; it can mask the early manifestations of vitamin B12 deficiency, which can lead to serious neurological damage, etc. 7, bone broth for calcium. The calcium in bone broth is difficult to be absorbed by the body, but also easy to combine with the soup inside fatty substances into saponification, which affects the absorption of calcium even more. 8, deliberate iodine supplementation. Iodine is widely present in the environment where people live, and as iodine has been compulsorily added to the edible salt in China, a normal diet will ensure that sufficient iodine is provided without additional supplementation. Excessive iodine intake can lead to a significant increase in the prevalence of thyroid. 9, vitamin over. Large amounts of vitamin A may lead to infant skeletal deformities, genitourinary system defects and hard palate openings; pregnant women taking large amounts of vitamin C for a long time can lead to miscarriage; too much vitamin D can lead to problems with the development of the fetus’s aorta and teeth; taking too much vitamin E can cause abnormal brain development in the fetus; too much vitamin B6, the fetus will be prone to vitamin B6 dependence. After the birth of the fetus, the source of vitamin B6 is not as adequate as in the mother, the child will be prone to excitement, crying and restlessness, easily frightened, eye fluttering. 10. Supplementation is too early. Early pregnancy is the most active stage of fetal organ development forging, taking too much vitamin A has a teratogenic effect, vitamin C superabundance can lead to miscarriage, supplemental vitamins should start from the middle of pregnancy. 11, abuse of supplements. Every day to supplement too many health products, such as protein powder, multivitamins, iron supplements, etc. can easily lead to vitamin and trace elements overload, affecting fetal development.