The entire gestation period is 10 months long, and during this long period, pregnant women may encounter some diseases that require medication. During pregnancy, the embryo or fetus is in different stages of development and the function of each organ is not yet perfect, so improper medication may have adverse effects on the embryo or fetus. The current problems in China regarding the use of drugs during pregnancy are twofold: on the one hand, pregnant women refuse to use drugs when they are suffering from various diseases that need to be treated with drugs, thus aggravating their conditions and delaying treatment; on the other hand, pregnant women who are ill and need to be treated with drugs have unreasonable drug choices. Therefore, it is very important to choose safe and effective drugs during pregnancy, and to use the right amount of drugs at the right time to improve the quality of the fetus. I. The effect of drugs on embryo and fetus: Whether the use of drugs during pregnancy will cause fetal malformation should take into account the nature of the drug itself, the dose used, the gestational age at the time of drug use and the possible individual differences in drugs, and the most important is the gestational age at the time of drug use. The higher the lipid solubility and the smaller the molecular weight of the drug, the easier it is to pass through the placenta, such as painkillers, sedatives, sleeping pills, etc. 2, the dose of drugs: the dose of drugs and its impact on the fetus has a great relationship, small doses of drugs sometimes only cause temporary damage, while large doses of drugs can cause serious effects on fetal development, and even cause embryonic or fetal death, the longer the use of drugs, the greater the impact on the fetus. 3, individual differences in the human body: the damage of drugs to the fetus and the genetic quality of the fetus, the same drugs, animals and animals and people have different effects, different people because of different genetic quality, the reaction to drugs are not the same. 4. Gestational age at the time of drug use: The gestational age at the time of drug use is closely related to the effect of drugs on the fetus, within 2 weeks after fertilization (within four weeks after the last menstruation), the effect of drugs on the embryo is “all” or “none”, “all In the case of “all” or “none”, the effect of drugs on the embryo is “all” or “none”. The 3-8 weeks after fertilization (i.e. 5-10 weeks after the last menstruation) is the stage of organ differentiation and development, during which the drugs have the greatest impact on the embryo, which is called the “highly teratogenic and sensitive period” and is prone to morphological abnormalities and various fetal malformations. The 9th week after fertilization (11th week of the last menstruation) to full term is the stage of fetal growth, organ development and organ function perfection, while the neurological system, reproductive system and teeth continue to differentiate, especially the neurological system differentiation, development and proliferation is at its peak in the late pregnancy and neonatal period. The effects of drugs during this period mainly cause abnormal development of the nervous system, reproductive system, and teeth. Damage to the nervous system is often manifested as behavioral abnormalities, such as hyperactivity in children after birth. Second, how to use the drug correctly during pregnancy and lactation: When using the drug for women with the possibility of conception, it is necessary to pay attention to whether the menstruation is overdue or not. If the menstruation is overdue, you should check whether you have conceived before using the drug. Pregnant women should tell their doctors that they are pregnant and the time of pregnancy when they visit other departments, and as doctors, whether they are obstetricians and gynecologists or other doctors, they should ask about the last menstrual period and the conception status when treating the disease to avoid any influence on the embryo or fetus. The health condition of the pregnant woman is very important for the growth and development of the fetus. If she is suffering from acute or chronic diseases, she should be treated before conception, and after being cured or under the supervision of a doctor, she should be pregnant. Pregnant women should seek medical advice in time and use the right medication. They should not delay treatment because they are worried about the effect of medication on the fetus, and try to use medication that has no or less effect on the fetus. Use drugs that can be used or not used during pregnancy, especially in the first three months of pregnancy. Tobacco, alcohol and narcotics are all drugs that are equally harmful to the pregnant woman and the fetus. Generally speaking, if you can use one drug, try to avoid the combination of multiple drugs, and if you can use a drug with a more definite conclusion, avoid using a newer drug that has not yet been confirmed to have an adverse effect on the fetus. The dose and duration of medication should be strictly controlled, and the medication should be stopped in time. If a pregnant woman has used a drug that has a serious effect on the fetus, she should consider it according to the dose and the week of pregnancy when the drug is used, and if a drug with obvious teratogenic effects is used during early pregnancy, termination of pregnancy should be considered. The use of drugs during breastfeeding generally does not require interruption of breastfeeding, and one may choose to take the drug immediately after breastfeeding, delay the next breastfeeding as much as possible, and extend the interval between drug administration and breastfeeding to reduce the drug concentration in breast milk. However, discontinuation of breastfeeding should be considered if the mother is using a drug that may potentially affect the infant.