Asthma during pregnancy is a special case of asthma. Controlling asthma is important for the health of both the pregnant woman and the fetus. 55% of female patients with a history of asthma have at least 1 acute asthma attack during pregnancy. One third of asthma patients have an exacerbation during pregnancy (mostly 24-36 weeks), one third have an improvement, and one third have no change in their condition. The effects of asthma on pregnancy are manifested by causing preterm delivery, dysplasia, growth retardation and low birth weight, leading to maternal pre-eclampsia, gestational hypertension, toxemia of pregnancy, vaginal bleeding and obstructed labor. Prospective studies have shown that patients with mild and moderate asthma have low maternal and infant risk during pregnancy; patients with severe asthma pregnancy have high maternal and infant risk (low birth weight babies, preterm delivery). Therefore, standardized treatment of asthma in pregnancy can improve the prognosis of both the patient and the fetus. The goal of controlling asthma in pregnancy is to achieve good asthma control, to help the mother pass through pregnancy to delivery, and to reduce infant mortality, preterm birth, and low birth weight. Principles of treatment during pregnancy: use non-pharmacologic therapies to reduce the effects on the fetus as much as possible, avoid drugs whose safety to the pregnant woman and fetus is still uncertain, try to use the lowest possible dose of drugs, try to administer drugs by inhalation, and reduce oral or injectable drugs. Because asthma is an airway hyperresponsiveness based on chronic airway inflammation, inhaled glucocorticoids are preferred for asthma treatment during pregnancy, in addition to theophylline and β2-agonists can also be used. I. Glucocorticosteroids Inhaled administration is the mainstay, which can effectively suppress airway inflammation and have low systemic adverse effects. Studies have shown that inhaled hormones do not correlate with fetal congenital anomalies or other adverse events during pregnancy. 1) Budesonide (Pramipexole): Class B. It is safe to apply during pregnancy and the therapeutic dose has no effect on the fetus. 2) Fluticasone and beclomethasone dipropionate: Class C (can be used during pregnancy, but the advantages and disadvantages should be weighed), Oral hormones: Short-term use: Systemic Few adverse reactions. Prednisone Q10mg/day, less adverse effects on pregnant women and fetus. β2-agonists are mainly nebulized and quantitative inhalers, which can rapidly relieve bronchospasm and maintain the effect for 4-6 h. They are suitable for patients with various degrees of asthma during pregnancy. Short-acting β2-agonists: terbutaline (Bolikonib, Asthma Concerns), salbutamol (Ventolin), can be used safely during pregnancy, long-acting β2-agonists (LABA): salmeterol, formoterol, although there is limited information about their use during pregnancy, their pharmacology and toxicology are similar to those of short-acting β2-agonists, and they can be used during pregnancy. Theophylline metabolism decreases during pregnancy, and theophylline clearance decreases by 20-35% in the second trimester. Therefore, theophylline must be monitored during pregnancy to maintain blood concentration at 5-12ug/ml to avoid theophylline toxicity. Theophylline has not been found to have teratogenic effects. Controlled release theophylline, the effect of bronchodilatation is maintained for 10-12 h. Aminophylline is used intravenously during acute asthma attacks. Anticholinergic drugs are mostly inhaled drugs, which can reduce vagal tone and relax bronchial smooth muscle. Ipratropium bromide (Echolal, class B), with minimal circulating absorption, has no significant CNS or systemic adverse effects. It is not a first-line treatment for asthma, and can be added to β2-agonists together with nebulization in acute asthma attacks. V. Sodium cromoglycate (Class B) can inhibit mast cell degranulation, as a prophylactic drug, inhaled before exercise or exposure to allergens to avoid acute asthma attacks. This drug does not pass through the placenta, systemic absorption <10%, can be used safely during pregnancy, and can be used in pregnant women with persistent asthma. Leukotriene modulators (montelukast, zallust) There are few clinical data on their use during pregnancy. In addition, treatment of asthma during pregnancy should follow the principle of prohibiting drugs harmful to the fetus. Class X drugs, isoprenaline and epinephrine are prohibited in pregnant women and should be used on balance and only in acute emergency asthma attacks. Rhinitis, sinusitis and gastroesophageal reflux are often associated with asthma and can exacerbate it. Those with allergic rhinitis should be controlled with low-dose glucocorticoids nasal inhalation, or second-generation antihistamines such as loratadine and cetirizine, and nasal decongestants may be used in early pregnancy. In addition to pharmacological treatment, non-pharmacological treatment of asthma in pregnancy is also important. First, avoid the effects of environmental factors and harmful irritants and sensitizers (stay away from tobacco, dust mites, pets, pollen, other pollutants and irritants indoors and outdoors); if gastroesophageal reflux is present, elevate the head of the bed and eat smaller and more frequent meals. For those who have started specific immunotherapy before pregnancy, it can be continued during pregnancy. Starting immunotherapy during pregnancy is not recommended to avoid allergic reactions. Patients with asthma who go into labor successfully go to the hospital for delivery as early as possible and cannot stop medication for asthma. Intensive oxygenation during delivery, correction of water, electrolyte and acid-base balance, and positive education and psychological guidance are given to prepare the mind and reduce tension and anxiety. The following drugs can be used for the pharmacological treatment of lactating asthmatics: prednisone, β2 agonists, sodium cromoglycate, theophylline, anticholinergic drugs, all of which are not contraindicated. Terbutaline, which can be secreted through breast milk, has not occurred in infants with symptoms to date. Theophylline can also be secreted from breast milk and 1% is absorbed by the newborn, because of individual differences, adverse reactions may occur in newborns.