300 million people worldwide suffer from asthma. The number of asthmatics is expected to increase by 100 million in 2025. Asthma is a chronic inflammation of the airways and is characterized by increased sensitivity of the tracheobronchial tree to multiple stimuli. It is also the most common chronic disease during pregnancy. The disease manifests episodically – with alternating clinical manifestations and symptom-free periods. Most asthma attacks resolve within minutes to hours, and patients appear to have fully recovered clinically in the inter-attack periods. The prevalence of asthma in the general population is about 4-5%, and in pregnant women it is about 1-4%. Women with mild asthma are unlikely to have problems during pregnancy, while with more severe forms the risk of worsening is greater and is higher in the latter part of pregnancy. Severe and uncontrolled asthma is associated with the following complications during pregnancy: Preeclampsia; Hypertension during pregnancy; Uterine hemorrhage; Premature birth; Congenital anomalies; Limited fetal growth; Low birth weight; Neonatal hypoglycemia, convulsions, tachypnea, conditions debilitating from intensive care. These risks can be significantly minimized by ensuring good asthma control. It is known that the birth of low birth weight babies is more common in women with daytime asthma symptoms than in women without asthma. Untreated and uncontrolled asthma during pregnancy can lead to respiratory failure and the need for mechanical ventilation, complications of systemic steroid administration. Pregnancy has a significant effect on a woman’s respiratory physiology – while vital lung capacity and respiratory rate do not change, minute ventilation and minute oxygen uptake increase by 40% and 20%, respectively. Total airway conductance increases and pulmonary resistance decreases. NEWS_MORE_BOX All these changes are probably due to progesterone. As a result of these physiological changes, hyperventilation is a normal state for the second half of pregnancy. Increased minute ventilation and improved lung function support more efficient gas exchange in pregnant women. That is why changes in the respiratory status of pregnant asthmatics occur much faster than in other women with asthma. Asthma itself is characterized by inflammation of the airways, a decrease in their diameter as a result of the swelling of the bronchial wall, blood filling the vessels, contraction of smooth muscles, accumulation of thick secretions. These changes lead to the symptoms of asthma – wheezing, shortness of breath, chest tightness, coughing. They are variable in time and are accompanied by variable airflow limitation. Stimuli causing an asthma attack: Allergens – pollen, house dust and the micro-mite in it, molds, etc.; Irritants – cigarette smoke, pungent smells,chemicals; Medical conditions – especially upper respiratory tract infections, sinusitis, reflux disease; Medicines – aspirin, non-steroidal anti-inflammatory drugs, beta-blockers; Physical effort; Cold air; Emotional stress. Almost all anti-asthma medications are safe to use during pregnancy. In fact, the most common situation during pregnancy is undertreated asthma because patients are concerned about the side effects on the fetus of using asthma medications. Maintenance therapy in pregnant asthmatics is similar to that of non-pregnant women. Beta-adrenergic agonists remain the mainstay of treatment for the onset of asthma symptoms and are the mainstay of mild asthma. In persistent asthma, an inhaled anti-inflammatory is recommended. In moderately severe persistent asthma – a beta-adrenergic agonist combined with an inhaled corticosteroid. In severe asthma – oral steroids and beta-agonists. Corticosteroids are relatively safe during pregnancy. In case of exacerbations, they are administered intravenously, intramuscularly and orally, while inhaled preparations are means of ambulatory maintenance of asthma control. Recent data on inhaled corticosteroids support their relative safety, although a potential risk for endocrine and metabolic disturbances in the offspring exists. Some studies show that long-term systemic administration of corticosteroids can lead to a slight increase in congenital malformations, premature birth, low birth weight, preeclampsia, gestational diabetes. Long-acting beta 2 agonists such as salmeterol are effective for nocturnal asthma symptoms. Magnesium sulfate, which is a smooth muscle relaxant and for the respiratory tract, is also a safe drug during pregnancy. In general, the risk of poorly controlled asthma appears to be much greater than the risk of taking medications to control asthma. Women who find out they are pregnant should continue their asthma medications because suddenly stopping the medications can be harmful to both them and their babies. The severity of asthma during pregnancy varies among women. It is difficult to predict what the course of the disease will be. During pregnancy, asthma worsens in about one-third of women, improves in one-third, and does not change in one-third. During the last month of pregnancy, asthma is usually milder. In women whose asthma improves, the improvement usually progresses during pregnancy. The severity of asthma symptoms during the first pregnancy is usually similar to that during subsequent pregnancies. Knowing the disease, its course and possible complications should be an essential part of keeping it under control. Measures such as building a plan of behavior when asthma symptoms appear, gaining knowledge about risk factors,training in the correct use of asthma medications, have a calming effect during pregnancy. Bibliography 1. Markus Little, MD, Asthma in Pregnancy, http://emedicine.medscape.com/article/796274-overview#showall 2. Steven E Weinberger, MD, Patient education: Asthma and pregnancy (Beyond the Basics), https ://www.uptodate.com/contents/asthma-and-pregnancy-beyond-the-basics More about the series “Women’s Health with Prof. Kostov” at Puls.bg and its author