Many women with asthma worry that their condition will worsen after pregnancy and affect the health of mother and child. In fact, it is estimated that about 36% of pregnant women with asthma have reduced asthma during pregnancy, 41% have no significant change, and only 23% of asthma patients may experience an exacerbation of their condition, a few of which may affect the mother and fetus. The change in asthma during pregnancy may be related to the change in hormonal secretion in the pregnant woman. What should women with asthma be aware of when they become pregnant? The following points are summarized: actively prevent asthma attacks, promptly relieve symptoms during attacks, pay attention to correcting hypoxia in pregnant women and avoid the use of drugs that are harmful to the fetus. After pregnancy, women with asthma should avoid asthma-promoting factors as much as possible, eliminate and avoid contact with various allergens in the living environment, such as pollen, dust, soot smell, spices, cold air and pets, prohibit smoking and avoid passive smoking, avoid mental stress and prevent respiratory infections. The main measures include prevention of dust mites, prevention of indoor air pollution, avoidance of allergenic foods, avoidance of allergic animal and plant contact, and maintaining emotional stability. Avoid going out during seasons when the concentration of allergens in the air increases, and during times when the air quality is poor. Maintain appropriate indoor temperature and humidity, avoid overexertion and mental tension, and pay attention to the prevention of respiratory tract infections and timely oxygen intake in case of oxygen deficiency to ensure adequate oxygen supply to the pregnant woman and the fetus. The first trimester of pregnancy is a critical period for fetal development, so the application of drugs should be strict and non-pharmacological therapy should be used as much as possible; after the third trimester of pregnancy, the use of drugs can be relaxed. Try to avoid the application of drugs whose safety for the pregnant woman and the fetus has not been determined. 2. Use medication by inhalation route as much as possible to reduce the chance of medication passing through the placenta when systemic medication is used. If the asthma attack is less than 2 times a week and the nighttime asthma attack is less than 2 times a month, β2 agonist inhaler can be used, which has no harmful effect on the fetus under the regular dose. Discontinue if symptoms are controlled. 3.Inhaled glucocorticoids are preferred for asthma control. 4.Minimize the possible harm to the fetus caused by hypoxemia. 5. The dose of asthma medication required to control asthma symptoms is minimal and adverse effects are controlled to a minimum. In general, according to the US FDA classification of antibiotics in pregnancy, penicillin, cephalosporins, macrolides, aminoglycosides and other antibiotics belong to the safer class B for pregnant women. However, considering the allergic status of pregnant women with asthma, macrolide antibiotics, i.e. erythromycin, roxithromycin, azithromycin, etc., are more suitable and have a lower chance of causing allergy. In addition to prevention and proper medication, the physiological condition of the pregnant woman and the fetus need to be monitored during pregnancy to detect early changes in the condition. Both the pregnant woman with asthma and the fetus need to be monitored for changes in their condition using appropriate screening methods. The maximum expiratory flow rate should be measured by a peak velocity meter at regular intervals until delivery. This is because the maximum expiratory flow rate can indirectly estimate airway hyperresponsiveness and allergic inflammation of the airway, and its decrease can precede the appearance of symptoms such as chest tightness and shortness of breath, which indicates an unstable state of asthma and a potential risk to the fetus, requiring immediate medication adjustment.