The first trimester of pregnancy is a critical period for embryo differentiation, and the use of drugs is generally not recommended. However, if a pregnant woman has a more serious bacterial infection and the benefits of using drugs outweigh the harms, she can use antibiotics that have less effect on the fetus, such as penicillin and cephalosporin, under the guidance of her doctor. Exposure to drugs that are harmful to the fetus in early pregnancy may cause fetal malformation, miscarriage, etc. Therefore, you should pay attention to keep your body healthy and protect yourself from cold and warmth in early pregnancy in order to minimize the production of diseases. If you are unfortunate enough to suffer from invasion of pathogenic bacteria, you can be treated with antibiotics under the guidance of your doctor if you are examined for bacterial infection. The use of antibiotics should pay attention to the use of drugs that have less impact on the fetus, such as penicillin, cephalosporin, etc. Try not to use aminoglycosides, such as gentamicin, streptomycin, etc., and quinolones, such as oxfloxacin, moxifloxacin, etc., which may cause fetal malformation. Pregnant women should seek timely medical treatment after illness, need to use the relevant drugs under the guidance of the doctor, do not take on their own at will.