Pregnant women and nursing mothers have a number of contraindications to the use of medications and should follow medical advice to avoid adverse reactions to the fetus in the womb and to the nursing child, which could have serious consequences. This article provides specific guidelines for the use of medications in pregnant and lactating women. We will provide them with the correct way to use medication for the normal growth and development of the fetus and young children. At present, with the development of science and technology, more and more drugs are widely used in clinical medical treatment, but for pregnant women and lactating women, there are certain limitations in the process of medication use. However, for pregnant women and breastfeeding women, the use of drugs is limited because some drugs have certain toxic side effects, which may adversely affect the fetus in the womb and inhibit the normal development of the fetus; in addition, breastfeeding, which is the best source of energy and nutrition, should not be contaminated. However, if incorrect medication is taken, it will cause the drug to enter the breast milk with the mother’s blood circulation. (1) Guideline of medication for pregnant women (1) Guideline of medication during the third month of pregnancy Generally, the most critical time for medication is during the second month of pregnancy, and improper use of medication at this stage may cause damage to the fetus or lead to fetal developmental malformations for a number of reasons, mainly because the medication may cause genetic mutations or chromosomal abnormalities. The following drugs must be banned: anti-tumor drugs, antibiotics, hormonal drugs, anti-epileptic and convulsive drugs, anti-allergic drugs, sedative drugs and anti-depressant drugs. (2) Guidelines for medication during the 4 to 9 months of gestation The use of medication during this period has serious effects on fetal brain development, neurological development and reproductive organ development, and special attention needs to be paid to the use of medication during the week before childbirth, as improper use may cause various adverse reactions in the fetus during delivery. In the later stages of life, the metabolism of drugs will occur, but due to the incomplete metabolism of young children, they cannot effectively excrete the drugs in a timely manner, which can cause drug allergic reactions in young children, and for premature babies, it is a great threat. The following drugs must be banned: drugs that promote protein synthesis, tetracyclines, sex hormones, tobacco, antihypertensive drugs, anticoagulants, sulfonamides, chloramphenicol, and iodides. Medications that can be used according to medical advice: vitamins, amphetamines, narcotics, kanamycin, antithyroid, diarrhea, phenytoinamide, reserpine, streptomycin, and norethindrone, etc. (3) Medication for women about two weeks before delivery Medication for pregnant women should not be neglected during this period because some medications can have a serious impact on the fetal heart rate, either too slow or too fast, and can even cause fetal convulsions, cyanosis and respiratory depression in severe cases. Other drugs may affect the hematopoietic function of newborns, inhibiting their hematopoietic function or causing jaundice, hypoglycemia and hemolytic anemia in young children, which may lead to death in severe cases. Special attention should be paid to the application of the following drugs: antibiotics, vitamins, antibacterial drugs, anesthetics, stimulants, antihypertensives, hypoglycemic drugs, diuretics, pupil-dilating drugs, analgesics, stimulants, antiarrhythmic drugs and antispasmodic drugs. (4) Guide to drugs not to be used by pregnant women during the Games The use of drugs during the Games sometimes does not affect the mother, but can still cause adverse effects on the fetus, leading to adverse effects on the development of fetal tissues and organs, and with the increase in the accumulation of drugs, the fetus can become toxic and brain development disorders. Valium, Advil, Librium, sleep-inducing drugs, nandrolone phenylpropionate, insulin, progesterone, cortisone and prednisone drugs, progesterone, testosterone, vitamin D, vitamin K, etc. 2. Guideline of medication for breastfeeding women The following drugs can cause adverse reactions to children. (1) The following drugs must be prohibited: bromocriptine, morphine, radioactive iodine, propylthiouracil, meprobamate, phencyclidine, benzindanedione, tetracycline, ergotamine, methotrexate, cyclophosphamide, cyclosporine, adriamycin, lithium, cocaine, isoniazid, etc. (2) Drugs that must be used with caution include the following: aspirin, clomastine, phenobarbital, paroxetine, salbutamol, phenytoin, prednisone, bromides, etc. (3) The main drugs that may be harmful to the baby during lactation are: central depressants, diazepam, lorazepam, cyclodiazepine, pralidoxime, chloral hydrate, antidepressants, amitriptyline, promethazine, amoxapine, desmethyl promethazine, duthiapine, antipsychotics, chlorpromazine, chlorprothixene, haloperidol, chloramphenicol, metoclopramide, metronidazole, tinidazole, etc. Conclusion When using drugs for pregnant and lactating women, it is important to strictly follow the above medication standards so as to effectively avoid various adverse reactions to the fetus and the newborn, and to promote the normal development and growth of the fetus and the newborn, so the correct choice of drugs in these two stages is of great significance.