AFP is the alpha-fetoprotein, usually expressed in capital letters, and can be detected by drawing blood from a vein. AFP is a protein that is synthesized by the liver and yolk sac during the fetal stage of life, and is suppressed soon after birth, resulting in a rapid decrease in the amount of AFP in the blood. The fetal production of alpha-fetoprotein will enter the mother’s blood through the placenta, which will lead to an increase in alpha-fetoprotein in pregnant women. It usually begins to rise in the 3rd-4th months of pregnancy and peaks in the 7th-8th months of pregnancy, with most being below 400ug/L and returning to normal in 3 weeks after delivery. AFP increases when a person has liver cancer, testicular cancer, ovarian cancer, teratoma, stomach cancer, and also increases when viral hepatitis and liver cirrhosis.