Alpha-fetoprotein is a monosaccharide protein that is synthesized by fetal hepatocytes and is a specific protein normally found in fetal serum. In adults, elevated AFP can be seen in primary liver cancer, active liver disease, reproductive tumors, pregnant women, pancreatic cancer and lung cancer. In addition to hepatocellular carcinoma, elevated fetoprotein can also occur in these conditions: 1. Pregnant women A transient increase in fetoprotein can also occur in women with normal pregnancy, but the increase is not as high as in hepatocellular carcinoma. Fetoprotein is produced in the fetus by the pregnant woman’s yolk sac and the fetal liver. Methemoglobin is the normal plasma protein component of the fetus and is the major protein of the early embryonic period. In pregnant women, the level of alpha-fetoprotein is significantly elevated, usually in the second trimester of pregnancy, reaching a peak and relatively stable level in the maternal blood of pregnant women in July-August, and gradually returning to normal levels about 3 weeks after delivery. 2. Neonatal hepatitis 30% of neonatal hepatitis can be measured with AFP, the incidence increases with the severity of the disease, mostly significantly higher. It should be distinguished from congenital biliary atresia, where the alpha-fetoprotein is mostly normal. 3. Acute/chronic hepatitis, cirrhosis In acute/chronic hepatitis, recovery from severe hepatitis or cirrhosis, serum alpha-fetoprotein may be elevated, but the magnitude of the increase is usually small and the duration is relatively short. For example, in patients with cirrhosis, the serum fetoprotein concentration is mostly between 25-200ng/ml, which usually decreases within 2 months with the improvement of the disease, and most of them do not exceed 2 months; it is accompanied by the increase of transaminase, and when the transaminase decreases, the fetoprotein also decreases, and the serum fetoprotein concentration is parallel to the transaminase. If the concentration of alpha-fetoprotein is high for a long time (above 500ng/ml) or progressively increasing, the occurrence of hepatocellular carcinoma should be alerted. 4. Other causes Liver injury, congestive hepatomegaly, capillary dilation, congenital tyrosinosis, testicular or ovarian embryonal tumors, some other gastrointestinal tumors, and pancreatic cancer patients may also have different degrees of elevated alpha fetoprotein.