The ancient book “The Remedies of Medicine and Treatment” says that “medicine is poisonous in three parts”, that is, medicine should be used carefully, weighing the pros and cons. During pregnancy, some drugs can affect the fetus directly, or indirectly through biological transformation into metabolites with teratogenic effects. The metabolic status of the pregnant mother, the growth and development of the fetus, and changes in the function of the placenta can affect the absorption, distribution, metabolism and excretion of drugs, and have different degrees of impact on the toxicity of drugs. Therefore, pregnant mothers must use drugs rationally! Let’s take a look at the effects of drugs on different periods of pregnancy: I. Before the fetal baby is born During pregnancy, the effects of drugs on the fetal baby are closely related to the gestational age when the drugs are used. Within 1 week of fertilization, or 3 weeks of gestation, which is the pre-birth period, medication has little effect on the baby. The effect of most drugs on the fetus at this stage follows the “all or nothing” principle. If the drug is extremely toxic to the blastocyst, it can cause a very early abortion. Either they do not affect the fetus and therefore generally do not increase the risk of malformation. This is the teratogenic period of drugs! At this stage, the organs of the fetal baby are highly differentiated, rapidly developing and constantly forming, firstly the heart and brain, then the eyes and limbs. The toxicity of drugs used by pregnant mothers at this time can interfere with the normal differentiation of fetal baby’s tissue cells, and any part of the cells affected by drug toxicity may cause malformation of one part of the tissue or organ. The earlier the toxic effects of drugs appear, the more serious the malformation may occur. Third, 12 weeks of pregnancy – before delivery Most of the organs of fetal babies have been formed at this stage, and the teratogenic effect of drugs is obviously weakened. However, some drugs may affect the organs that are not yet fully differentiated, such as the reproductive system. As the nervous system continues to differentiate and develop during the whole pregnancy, the effect of drugs on the nervous system can exist all the time. Fourth, during childbirth The use of drugs during childbirth should also take into account the impact on the newborn baby to be born. For example, when general anesthesia is used as a last resort in emergency situations, the anesthetic drugs have a whistling inhibitory effect on the newborn baby. Therefore, pregnant mothers of cesarean section should not ask the anesthesiologist to “general anesthesia” if not medically necessary! 5. Can I still take medication during pregnancy? Of course you can! Not all drugs have teratogenic risks. If you get sick during pregnancy, certain diseases themselves may affect your baby if left untreated, even miscarriage and premature birth. Therefore, it is necessary to go to a regular hospital for treatment during pregnancy and not to carry on without treatment. When visiting a specialist (such as dentistry, internal medicine, surgery, etc.), be sure to clearly inform the doctor of your pregnancy status. The principles of medication for pregnant mothers 1. must have clear indications to avoid unnecessary medication; 2. use medication under the guidance of a doctor, do not use drugs without authorization; 3. can use a drug, avoid combined medication; 4. can use drugs with more certain efficacy, avoid using new drugs that are difficult to determine whether there are adverse effects on the fetal baby; 5. can use small doses of drugs, avoid using large doses of drugs; 6. strictly control the dose and duration of medication If the condition of early pregnancy allows, try to postpone the use of drugs until the middle and late pregnancy; if the condition requires the application of teratogenic drugs harmful to the fetus in early pregnancy, the pregnancy should be terminated first, and then the drugs should be used. 7. Unavoidable question 1: Is Chinese medicine safe? Chinese medicines, especially proprietary Chinese medicines, are complex in composition and there is no recognized system for evaluating the safety of Chinese medicines, so I dare not easily tell pregnant mothers which Chinese medicines can be used and which cannot. The second question that cannot be avoided is: Can I have a pregnancy after taking medicine? At this time we need to be cautious and not to decide without permission. It is advisable to consult an obstetrics or prenatal diagnosis specialist, and it is best to clarify the time of your last menstrual period and the specific time of your sexual life that may lead to conception before consulting a doctor. It is also necessary to clarify what specific medication you are using, the timing and dosage of the medication, and it is best to bring the medication box with you. Nine, the drug to the fetus harm grade (U.S. FDA grading) Class A: the highest safety at normal doses, is not teratogenic drugs, such as vitamins. Grade B: Animal experimental studies have not seen any harm to fetal babies. Can be used under physician’s observation, such as penicillin, insulin, etc. Grade C: Animal experiments have shown adverse effects on the fetal baby. Weigh the pros and cons and use with caution. Grade D: There is sufficient evidence of harm to the fetal baby. Consider use only if the pregnant mother has a life-threatening condition or is seriously ill and other drugs are ineffective. Grade X: Animal and human studies have confirmed that it causes malformation of the fetal baby. Contraindicated during pregnancy or in women who are at risk of pregnancy. Class C, D, and X drugs should not be used during the first 12 weeks of pregnancy! It is not easy to get pregnant, and we should cherish it when we are pregnant. We should not easily give the death sentence to the life of the fetal baby because of some medicine, and we should not use medicine randomly without regard to the safety of the fetal baby.