Pregnant and breastfeeding women should use cold and flu medicines with special caution. Aspirin, diclofenac sodium, benadryl, ibuprofen and dextromethorphan should not be used in pregnant women as much as possible, so as not to affect the development of the fetus or lead to prolongation of pregnancy. Guaiacol glyceryl ether is contraindicated during the first trimester of pregnancy. (See the 2012 Expert Consensus on the Standardized Diagnosis and Treatment of the Common Cold.) There are many types of anti-cold medications available at the pharmacy, which ones are safe to choose? Decongestants Pseudoephedrine is commonly used to selectively constrict blood vessels in the upper airways and has a low effect on blood pressure. Pseudoephedrine has a pregnancy classification of C. The effects on the human fetus lack sufficient case reports and reliable controlled studies, and its chemical structure suggests that it can pass the blood-fetal barrier. Epidemiologic studies have shown an approximately 4-fold increase in the incidence of ventral clefts and small bowel atresia in fetuses exposed to this product, and smoking further increases this risk. It is contraindicated in early and mid-pregnancy. Antihistamines are an option for nasal congestion during pregnancy. Antihistamines Chlorpheniramine maleate, the preferred first-generation antihistamine for the common cold, has the ability to penetrate the blood-brain barrier and penetrate into the CNS cells to bind to histamine receptors, as well as an anticholinergic effect, which helps to minimize secretions and reduce coughing symptoms. Chlorpheniramine pregnancy classification B. Loratadine, a second-generation antihistamine, is classified as Pregnancy Category B. In a recent CDC analysis of data from the National Birth Defects Prevention Study, there was no elevated risk of 2nd or 3rd degree hypospadias in male offspring of mothers who used loratadine in early pregnancy. Recent Danish studies have also confirmed these findings. Therefore, loratadine is safe when used in pregnancy for the indicated indications. Cetirizine, a second-generation antihistamine, is pregnancy class B. Studies in rodent pregnancies have shown it to be safe, with no evidence of teratogenicity or intrauterine fetal growth retardation, although it has been used at doses higher than those used in clinical practice. Cough suppressants Commonly used are central cough suppressants such as codeine and dextromethorphan, and peripheral cough suppressants such as nalcodone and benadryl. Codeine has a pregnancy classification of C. It readily crosses the blood-fetal barrier and has not been shown to be teratogenic in rodent studies. Intrauterine fetal growth retardation occurs at doses lower than those used for maternal toxicity, and neonatal withdrawal syndrome has been reported. Dextromethorphan has a pregnancy classification of C. There are no extensive case reports or rigorously controlled studies of this drug in pregnant women. Dextromethorphan is teratogenic in a chick embryo model. Dextromethorphan is contraindicated in the first trimester of pregnancy. Expectorants Expectorants commonly used include guaiacol glyceryl ether, ambroxol, and bromhexine, of which guaiacol glyceryl ether is a commonly used ingredient in combination cold remedies. Guaiacol glyceryl ether has a pregnancy classification of C. Guaiacol glyceryl ether is contraindicated during the first trimester of pregnancy. Preclinical trials and extensive clinical experience with Ambroxol after 28 weeks of gestation have shown no adverse effects on pregnancy. However, the drug should be used with caution during pregnancy, especially in the first trimester. Bromhexine is a precursor drug of Ambroxol, which is metabolized into Ambroxol to exert expectorant effects, and should be used with caution in pregnant women. Ambroxol can be used to resolve phlegm during pregnancy. Acetaminophen and ibuprofen are the main antipyretic and analgesic drugs. Acetaminophen is classified as pregnancy grade B. The drug can cross the placenta and can be used throughout pregnancy to relieve pain and reduce fever. Acetaminophen is preferred in the first 3 months of pregnancy. Ibuprofen Pregnancy Category B. Ibuprofen is associated with an increased prevalence of abdominal wall defects and ventricular septal defects. Ibuprofen may increase the risk of spontaneous abortion when used before pregnancy and is a grade D when taken late in pregnancy. The common cold is a self-limiting disease, mostly caused by viral infections. Antibacterial drugs cannot kill viruses, so antibacterial drugs are not recommended for the treatment of the common cold, and antibacterial drugs should be considered only when combined with bacterial infections. If the temperature exceeds 38.5℃, acetaminophen is recommended. Pay attention to drink more hot water, avoid going in and out of crowded public places, avoid getting cold and overwork.