1. Basic principles of medication during pregnancy In order to reduce the possible adverse effects of drugs on the fetus, some of the following basic principles of medication during pregnancy should be followed. 1.1 Try to avoid unnecessary medication Women should not use large amounts of even vitamin drugs during pregnancy to avoid adverse reactions to the fetus. For example, large amounts of vitamin A during pregnancy can lead to skeletal abnormalities or congenital cataracts in the fetus; another example is that excessive vitamin D can lead to fetal mental retardation and aortic stenosis. 1.2 Medication should be used under the guidance of a doctor Medication during pregnancy should be emphasized to be used under the guidance of a doctor, and pregnant women should not use drugs without authorization. According to the literature, about 65% of pregnant women purchase and take drugs on their own, and the misuse of drugs harmful to the fetus occurs repeatedly. Therefore, it is necessary to strengthen the publicity and education. 1.3 Avoid medication in early pregnancy. In early pregnancy, if it is only to relieve general clinical symptoms or if the condition is mild enough to allow postponement of treatment, postpone treatment until the middle or late pregnancy. Some drugs taken in late pregnancy can compete with bilirubin for protein binding sites, causing an increase in free bilirubin, which can easily lead to neonatal jaundice. Some drugs can easily pass through the fetal blood-brain barrier and cause intracranial hemorrhage in the newborn, so attention should be paid to discontinuing the drugs one week before delivery. 1.5 Careful selection of therapeutic drugs Avoid combining drugs if they can be used alone during pregnancy; when new drugs and old drugs are equally effective, old drugs should be used, because most new drugs have not been fully validated for their effects on the fetus and the newborn, so the use of new drugs should be more careful. The classification system of drugs used in pregnancy developed by the US Food and Drug Administration (FDA) can be referred to in order to choose the drug with the least effect on the fetus without affecting the clinical treatment effect. 1.6 Weighing the pros and cons of using drugs that may affect the fetus but can be used to treat diseases that endanger the health or life of the pregnant woman should be used after weighing the pros and cons fully. The dosage should be adjusted at any time according to the condition, and the drug should be stopped in time, and blood concentration monitoring should be performed when necessary. In addition to the above, pregnant women should be advised to stop smoking and drinking. Although tobacco and alcohol are not medicines, they are harmful to the fetus. The smoking rate of pregnant women in China is not high, but the phenomenon of passive smoking is more common. Some local customs believe that glutinous rice wine can nourish the body, but do not know that drinking it will have a negative impact on the fetus, so we must strengthen the publicity and education in this regard. 2. Precautions for the use of drugs during lactation Whether lactating mothers can continue to breastfeed in the case of drug use is a matter of concern, and there are often many different opinions and confusion, so that clinicians are at a loss. In general, the amount of drugs in breast milk rarely exceeds 1%-2% of the mother’s dose, and only some of them are absorbed by the baby, so there is usually no significant risk to the baby. However, in order to minimize or eliminate the possible adverse effects of drugs on the breastfed child, the following matters should be noted: ① the mother should have clear indications for the use of drugs; ② without affecting the therapeutic effect, choose the drug that enters the breast milk the least and has the least effect on the newborn; ③ breastfeeding can be done immediately after taking the drug, and the next breastfeeding time can be postponed as much as possible, so that the breastfed child can avoid the peak of the drug when sucking breast milk, and can also The optimal interval between drug administration and breastfeeding can be adjusted according to the half-life of the drug; ④ If the mother applies a large dose of the drug or a long course of treatment, which may have an adverse effect on the baby, the blood concentration of the baby should be tested; ⑤ If the mother must use the drug and cannot confirm whether the drug is safe for the newborn, breastfeeding can be suspended; ⑥ If the drug applied by the mother can also be used to treat neonatal diseases, breastfeeding is generally not affected. 3. Avoid “neglecting medication” The so-called “neglecting medication” refers to women who may conceive or have conceived, who ignore their menstrual history or fail to discover that they have conceived when using medication, and mistakenly use some medication that is harmful to the fetus. These cases are common in eugenics consultation clinics. The common drugs that can have harmful effects on the fetus when taken by pregnant women are antiviral drugs such as ribavirin (virazole); antibacterial drugs such as ofloxacin, ciprofloxacin, etc.; antiemetic drugs such as benadryl, metoclopramide (antiemetic), etc. Therefore, doctors should not forget to ask about the last menstrual period and conception when taking medical history to avoid “neglecting to use drugs The “neglect of medication” to the pregnant woman left mental burden or increase the pain of abortion. 4, do not “delay medication” “delayed medication” refers to the need for drug treatment of pregnant women, because of concern about the impact of drugs on the fetus and delayed medication, resulting in the deterioration of the condition, endangering the life of the mother and child. For example, in the case of serious infectious diseases, the lack of timely use of effective antibiotics leads to deterioration of the condition, resulting in sepsis and infectious shock; some patients with hyperthyroidism combined with pregnancy do not receive timely antihyperthyroidism treatment, resulting in the progression of the condition and even hyperthyroid crisis, which endangers the life of the patient; another example is that most of the anti-seizure A drugs have an effect on the fetus, but pregnant women with frequent seizures of A If anti-epileptic drugs are not used in time, the effect of seizures on the fetus may be even greater. Pregnant women with the disease should be diagnosed promptly and given reasonable treatment, including medication and consideration of the need to terminate the pregnancy. 5. Fetal toxicology and eugenic counseling The main factors of adverse effects of drugs on the fetus and newborn include the nature of the drug itself, the dose of the drug, the duration of drug use, the route of drug administration and the affinity of the fetus or newborn for the drug, the most important of which is the gestational age at the time of drug administration. Within 1 week after fertilization, the fertilized egg has not been planted in the endometrium and is generally not affected by drugs used by pregnant women; 8-14 days after fertilization, the fertilized egg has just been planted in the endometrium and the embryonic layer has not yet differentiated, so the influence of drugs does not cause malformation except for miscarriage; 3-8 weeks after fertilization is an important stage of embryonic organogenesis, and the sprouts of various organs are differentiated and developed during this stage, which are most susceptible to the influence of drugs and the external environment. The fetal organs have been differentiated and continue to develop from 9 to 27 weeks of gestational age, and the toxic effects of drugs mainly cause fetal developmental abnormalities such as intrauterine growth retardation. From 28 weeks of gestation to delivery, i.e., late gestation, drugs can cause toxic effects on the fetus, especially when some drugs compete with bilirubin for the binding sites of plasma proteins, leading to neonatal jaundice or even kernicterus.