The maximum safe value of alpha-fetoprotein value during pregnancy is 550ng/ml. Generally the value of alpha-fetoprotein in the body of a pregnant woman rises at 12 to 14 weeks of pregnancy, and the normal values at different times are: 1. 3rd month of pregnancy: 18~113 ng/ml. 2. 4 to 6 months of pregnancy: 160 to 550 ng/ml. 3. 7th to 9th month of pregnancy: 100～400 ng/ml. 4. 20 days after delivery to normal. Alpha-fetoprotein (AFP) is a serum alpha glycoprotein synthesized by the liver and yolk sac in the early stage of fetal development, with the highest concentration in the growing period of the fetus and a very low serum level after birth. When the liver cells are malignant, the relevant genes are activated and synthesize AFP, which leads to a significant increase in the AFP level in the blood. If AFP exceeds the above normal value during pregnancy, pregnant women need to consult a doctor to check the cause of the disease and take appropriate measures to treat the cause.