It is possible to take medications in the 1st month of pregnancy, such as vitamin C, vitamin D, folic acid, etc. However, since the first month of pregnancy belongs to the early stage of pregnancy, which is an important stage for the development of the fetal organs, some drugs may have certain effects on the embryo, so it is necessary to choose and take the drugs under the guidance of a professional doctor. The selection of specific drugs can be referred to, by the FDA issued by the pregnancy drug classification (a total of five levels: A, B, C, D, X level), for clinical reference in the selection of safe use of drugs during pregnancy, mainly divided into the following two cases: a. Pregnant women available drugs 1, Class A drugs: no signs of drug harm to the fetus, common drugs are vitamin C, vitamin D, vitamin E, potassium chloride, levothyroxine sodium 2. Class B drugs: No adverse effects of drugs on the fetus are seen. Common drugs include insulin, famotidine, etc. Pregnant women should use drugs with caution 1. Common drugs include aspirin, hydrocortisone, gentamicin, etc.; 2. Class D drugs: the effects of fetal teratogenicity or miscarriage, but beneficial to the pregnant woman, need to weigh the pros and cons after careful use, such as using the drug to save the life of the pregnant woman, or treating serious diseases that are not effective with other safer drugs. Common drugs include sulfamethoxazole and carbamazepine. These drugs have an effect on the fetus, the toxicity is relatively large metabolism is also slow, if after using these drugs, it is best to use the drug 3-6 months before pregnancy; 3, X-rated drugs: drugs are harmful to the fetus. And pregnant women do not benefit from the application of these drugs, so it is prohibited in patients who are pregnant or may become pregnant. Common drugs are ribavirin, eszopiclone, etc.