When the fertilized egg of normal pregnancy is implanted, HCG will be secreted when the fertilized egg trophoblast is formed on the 6th day after ovulation. The HCG in peripheral blood can be monitored for about one day, and then it will be doubled every 1.7~2 days. The HCG in blood is >:100 U/L for 30 days of pregnancy and > for 40 days of pregnancy. At 2000U/L, it reached its peak at 8~ 10 weeks of pregnancy, and the blood HCG was 50000 ~ 1000000 U/L, and then decreased rapidly. In the second and third trimester of pregnancy, the blood HCG is only 10% of the peak value. Early pregnancy reactions in early pregnancy, such as nausea, vomiting, general fatigue, drowsiness, etc. It is closely related to the increase of HCG in blood. With the decrease of HCG in blood, the early pregnancy reaction will gradually disappear.

Pay attention to the diet in the second trimester:

1, the diet should be rich in calcium.

Calcium is an important component to form bones and teeth, help muscle contraction and maintain blood function, and it needs to be taken in large quantities in the second trimester. Sardines and dried fish are important sources of calcium, but choose foods with less salt. Dairy products, green vegetables, eggs, almonds and sesame seeds are all rich in calcium. High calcium food can improve the absorption rate if it is eaten with beef, pork and chicken.

2. Adequate iron intake

Iron intake can prevent anemia. Foods rich in iron include red meat and animal liver. If iron food is taken together with vitamin C, the absorption rate will be higher, because vitamin C can promote the body's absorption of iron. On the contrary, black tea, coffee and other drinks contain caffeine, which will hinder the absorption of iron in the body. Pregnant mommy can't drink these drinks before eating 1 hour.

Step 3 eat foods rich in cellulose

Eating more foods rich in cellulose can effectively prevent constipation, but it should be eaten in moderation to avoid affecting the absorption rate of calcium and iron. In order to get enough cellulose, pregnant women can replace white rice with miscellaneous grains rice, replace broth or chicken soup with vegetable soup, and eat more fresh fruits and vegetables. Eat more than two kinds of vegetables every meal, and eat kelp, seaweed, kelp, seaweed and other foods with Shanghai algae every day.