The fourth month of pregnancy is already in the middle of pregnancy, and the safety of cephalosporins is better, so the effect on the fetus is relatively small. However, it is recommended that they be used with caution after a thorough evaluation. Cephalosporins are widely used antibiotics in clinical practice, belonging to the β-lactam class. Current clinical data show that cephalosporins are not teratogenic and have a relatively small effect on the fetus and newborn, and the commonly used cephalosporins such as cephalexin, cefuroxime, and cefoperazone belong to the B class of gestational drugs, which are safe to be used during pregnancy and lactation. However, it should be noted that before using cephalosporins, it is necessary to clarify the existence of sensitive bacterial infections, and exclude drug allergies and other contraindications to the use of drugs. In the use of drugs need to monitor changes in the condition of the disease, fetal status and adverse reactions, if necessary, need to stop using the drug. In addition, the use of cephalosporins should be carried out under the guidance of a doctor, and should not be taken at random.