Many patients with hepatitis B in pregnancy consult which drugs can be used, and now the drug safety level is written as an article for your reference. In order to systematically understand the effects of drugs on the fetus and facilitate clinicians’ access and use, the FDA has established the following classification criteria according to the different hazards of drugs: Class A: The possibility of harm to the fetus is minimal because it cannot be confirmed by clinical control studies that the drugs are harmful to the fetus in early pregnancy and middle and late pregnancy. It is a drug without teratogenicity. Grade B: No harmful effects on fetus were observed by animal experimental studies. No clinical control experiment, no evidence of harmfulness was obtained. Can be used under physician’s observation. Class C: Animal experiments have shown adverse effects on the fetus. Since there is no clinical control experiment, the drug can only be used with caution after fully weighing the benefits of the drug to the pregnant woman, the potential benefits to the fetus and the harm to the fetus. Class D: There is sufficient evidence of fetal harm. Consider use only if the pregnant woman has a life-threatening or serious illness and other drugs are ineffective. Grade X: Various experiments have confirmed that it causes fetal abnormalities. There is little to no benefit beyond the harm to the fetus. It is a drug prohibited before or during pregnancy.