Pregnancy is a very special time when the fetus may be exposed to health threats from all directions. In our clinical work, we find that many expectant mothers are troubled by the use of medications during pregnancy and struggle to make choices. Since certain drugs can affect the embryo indirectly by affecting the mother’s endocrine and metabolism, and can also affect the fetus directly through the placental barrier, medication during pregnancy should be used very carefully and must be chosen strictly, and not to be used casually unless it is necessary. The effects of drugs on the fetus during various periods 1. Pre-fertilization period: The fertilized egg is not yet in direct contact with the maternal tissues during this period, so the drugs used by pregnant women during the pre-fertilization period have little effect on them. However, if the drug is extremely toxic, it may cause very early miscarriage. 2.After the fertilized egg is laid until about 12 weeks, the embryo and fetal organs are in the stage of high differentiation, rapid development and continuous formation. This period is the most sensitive period of drug teratogenesis. 3.After the 4th month of gestation, the organs of fetus have been formed, and the possibility of drug causing fetal malformation decreases, and it is no longer able to cause a wide range of malformation, but some organs that have not been fully differentiated, such as the reproductive system, may still be affected to different degrees. The nervous system continues to differentiate and develop throughout pregnancy, so the effect of drugs on the nervous system can always exist. China’s medication grading for pregnant women Currently, China’s medication for pregnant women is borrowed from the standards set by the U.S. Drug and Food Administration and is graded as follows: Class A drugs: safe for pregnant women and not harmful to the embryo and fetus. For example, appropriate amount of vitamin A, B, C, D, E, potassium chloride, levothyroxine sodium tablets, etc.; Class B drugs: safe for pregnant women and basically harmless to the fetus. Such as penicillin, erythromycin, digoxin, insulin, etc.; amoxicillin, ampicillin, almost all cephalosporin antibiotics, clotrimazole, insulin, ibuprofen (but the side effects of drugs in late pregnancy, near delivery are large, be very careful), acetaminophen. Class C drugs: only proven to be teratogenic to the fetus or can kill the embryo in animal experimental studies, not confirmed in human studies, pregnant women need to weigh the pros and cons of using drugs to confirm that the benefits outweigh the disadvantages before application. For example, erythromycin, azithromycin, gentamicin, spiramycin, ciprofloxacin, ofloxacin, metronidazole, famotidine, acyclovir, iproniazid, isoniazid, miconazole, hepatitis B vaccine, aspirin, hydrocortisone, and mycobacterium. Class D drugs: There is definite evidence of harm to the fetus, and the application is not considered unless there is an absolute effect after the drug is administered to pregnant women. For example, streptomycin (causes damage to the 8th pair of brain nerves and hearing loss in the fetus), tetracycline hydrochloride (causes cleft palate and anencephaly in the fetus), kanamycin, aminoglutethimide, bacitracin, iodine, sulfamethoxazole, carbamazepine, lorazepam, cilazepril, etc. Class X drugs: can cause fetal abnormalities and are prohibited during pregnancy. For example, methotrexate (can cause fetal cleft lip, cleft palate, anencephaly, hydrocephalus, meningocele, etc.), hexestrol (can cause vaginal adenopathy, vaginal clear cell carcinoma), chloramphenicol: inhibit fetal bone marrow hematopoiesis and cause neonatal pulmonary hemorrhage. Ribavirin, eszopiclone, fluvastatin, paclitaxel, norethindrone, mifepristone, rubella vaccine, measles vaccine, etc. In the first 3 months of pregnancy, it is better not to use C, D or X drugs. In case of emergency, we should try to use A and B grade drugs that have been clinically proven to be non-teratogenic for many years. Western medicine should be strictly selected, so is Chinese medicine necessarily safe? The answer is no. Some herbal medicines have adverse effects on pregnant women and fetuses. For example, saffron, Citrus aurantium, Pu Huang, musk, angelica, etc. have the effect of stimulating the uterus, which can easily lead to fetal ischemia and hypoxia, resulting in fetal maldevelopment and malformation, and even cause miscarriage, premature birth and stillbirth; rhubarb, mannitol, rhubarb, Shanglu, croton, coriander, petunia, gansui, etc. can cause strong contraction of the uterus by stimulating the intestinal tract and reflexively, resulting in miscarriage and premature birth. Some of the drugs themselves have certain toxicity, such as Zanthoxylum, Shengnanxing, Epiphyllum, Aconite, Artemisia, Sichuan pepper, Centipede, Gansui, Coriander, Cinnabar, Xionghuang, Euphorbia, Shangluo, Croton, etc. They contain a variety of alkaloids and chemical composition is very complex, and some can directly or indirectly affect the growth and development of the fetus. The teratogenic effect of Xiong Huang is certain, pregnant women should be absolutely forbidden to take. Cinnabar contains leachable mercury salts that cause microcephaly, deafness, strabismus, and mental retardation in newborns. At the same time, Chinese medicine believes that if pregnant women indiscriminately take ginseng, cinnamon, astragalus and other sweet warm tonic, sweet warmth is very easy to help fire, moving the fetus and blood, for pregnant women with internal heat Yin deficiency, is like adding fuel to the fire, is likely to cause preterm abortion or premature birth. It is important to note that many herbs with toxic side effects are often found in the form of formulas in proprietary Chinese medicines. So be wary of pCms containing these ingredients, and avoid taking pCms that are banned or used with caution by pregnant women. During the course of pregnancy, if the mother-to-be has any abnormalities, she must go to the hospital in time to get professional and regular guidance on medication so that the fetus in the womb and you can spend the pregnancy period healthily.