Bronchial asthma and pregnancy

Asthma is a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role. Chronic inflammation causes a concomitant increase in airway hyperreactivity, leading to recurrent episodes of wheezing, shortness of breath, chest tightness, and cough, especially at night or in the early morning. These episodes are usually associated with widespread but variable airflow obstruction that is reversible spontaneously or with treatment.

Epidemiology

The incidence of bronchial asthma has increased significantly in the last three decades, and, according to WHO experts, it is considered one of the most common chronic human diseases. Bronchial asthma has been diagnosed in 8-10% of the adult population, and among children, depending on the region, from 5 to 15%. At the same time, the number of sick children is growing every year. In our country, more than 8 million people suffer from this disease.

Women suffer from bronchial asthma twice as often as men. The disease usually manifests itself at a young age, which certainly leads to an increase in the number of patients with bronchial asthma of childbearing age.

The prevalence of bronchial asthma in pregnant women varies from 1 to 8%. It has been proven that bronchial asthma leads to complicated pregnancy. The most common complications are gestosis (46.8%), threatened miscarriage (27.7%), and fetoplacental insufficiency (53.2%). Among newborns, intrauterine growth retardation is detected in 28.9%, hypoxic cerebrovascular accident in 25.1%, and intrauterine infection in 28%.

Kwon et al. [ 1 ] reported an increase in the prevalence of asthma during pregnancy from 3.7% in 1997 to 8.4% in 2001. More recent reports from the USA found a prevalence of 5.5% in 2001, increasing to 7.8% in 2007. [ 2 ] A prevalence of 9.3% has been reported in Ireland [ 3 ] and 12.7% in Australia. [ 4 ] Maternal asthma is associated with an increased risk of adverse perinatal outcomes, and changes in the course of the disease are expected and may be unpredictable during pregnancy.

Pathogenesis

The pathogenesis of remission or exacerbation of asthma during pregnancy is associated with physiological or pathological changes caused by pregnancy, mainly mechanical changes caused by the enlargement of the uterus, as well as the direct or indirect influence of hormonal changes during pregnancy.

With increasing uterus and abdominal pressure, the diaphragm is raised by 4-5 cm, the subcostal angle increases by 50% (from 68° to 103° from early to late pregnancy), and the transverse and anteroposterior diameters of the chest increase. The above changes are partially compensated by the relaxation of the ligamentous attachment of the ribs, which leads to a decrease in the compliance of the chest. As a result, the total lung capacity decreases by 5%, and the FRC (functional residual capacity) decreases by 20%. [ 5 ] Moreover, increased body weight leads to an increase in neck circumference and a decrease in the area of the oropharynx, which contributes to dyspnea during pregnancy. [ 6 ]

During pregnancy, to meet the metabolic needs of the mother and fetus, a number of important changes in hormone levels occur, including an apparent increase in progesterone, estrogen, cortisol, and prostaglandin levels, which have different effects on asthma.

Progesterone is a stimulant of respiratory dynamics, capable of increasing the sensitivity of the respiratory center to carbon dioxide, while estrogens can increase the sensitivity of progesterone receptors in the respiratory center and jointly participate in changing the respiratory function. Minute ventilation increases by 30-50%, which occurs mainly due to an increase in tidal volume by 40%, while there is no significant change in respiratory rate. TLC (total lung capacity), VC (vital lung capacity), lung compliance and DLCO (diffusion capacity) remain unchanged.

FVC (forced vital capacity), FEV1 (forced expiratory volume in 1 second), FEV1 to FVC ratio and PEF (peak expiratory flow rate) do not change significantly during pregnancy compared to the absence of pregnancy. Therefore, spirometry can be used to detect dyspnea in normal pregnancy and reflect changes in respiratory diseases. In addition to the effect on the respiratory center, progesterone can mediate vasodilation and mucosal congestion, which leads to an increase in the incidence of rhinitis and epistaxis in pregnant women, [ 7 ] as well as oropharyngeal and laryngopharyngeal airways, which contribute to an asthma attack during pregnancy.

Estradiol can enhance maternal innate immunity as well as cellular or humoral adaptive immunity. Low estradiol concentrations can promote CD4+Th1 cellular responses and cellular immunity. High estradiol concentrations can enhance CD4+Th2 cellular responses and humoral immunity. Progesterone suppresses maternal immune responses and alters the balance between Th1 and Th2 responses. Although cell-mediated immunity is more important in respiratory viral infections, the shift from Th1 to Th2 immunity is considered an important mechanism in hormone-induced asthma during pregnancy. [ 8 ], [ 9 ]

Women are in a state of hypercortisoneism during pregnancy; meanwhile, the placenta secretes both CRH (corticotropin-releasing hormone) and ACTH (adrenocorticotropic hormone), which leads to an increase in free cortisol and conjugated cortisol during pregnancy. Increased free cortisol mediates an increase in beta-adrenergic receptors and an increase in bronchiectasis. Increased secretion of prostaglandin E2 (PGE2) during pregnancy through anti-inflammatory effects, inhibition of smooth muscle cell proliferation, bronchial relaxation and other mechanisms exerts a protective effect on the incidence of asthma. In addition, progesterone also affects the change in airway smooth muscle tension and causes bronchiectasis. These factors are associated with remission of asthma during pregnancy.

Generally speaking, the influence of mechanical and biochemical changes on the respiratory system of pregnant women is very complex, especially the influence of various hormones on the respiratory center, peripheral airways and the immune system, which leads to pregnant women without asthma experiencing dyspnea of varying severity during pregnancy. For pregnant women with asthma, it is very important to strengthen asthma management during pregnancy to avoid maternal hypoxia and maintain adequate oxygenation of the fetus.

Symptoms bronchial asthma in pregnancy

Generalized asthma is defined by a history of more than one type of respiratory symptoms, such as wheezing, shortness of breath, chest tightness, and cough, that vary in timing and intensity, often appear or worsen with viral infections, and occur at night or on awakening, usually triggered by exercise, laughter, allergens, and cold air, and variable expiratory airflow limitation.[ 10 ] If one of the tests is positive, including the bronchodilator reversibility test, bronchial provocation tests, and PEF variability, this may confirm variable expiratory flow limitation.

Compared with general asthma, asthma in pregnancy has similar clinical manifestations. However, if a pregnant woman complains only of shortness of breath or chest tightness, physicians should be cautious in making a diagnosis based on her medical history. It is known that more than two-thirds of pregnant women experience some form of shortness of breath or chest tightness during pregnancy due to physiological changes during pregnancy. In addition, it is not advisable to perform a bronchial provocation test to prevent maternal hypoxia and fetal distress.

Forms

Bronchial asthma can be classified based on the etiology, severity and temporal characteristics of bronchial obstruction.

Classification by etiology, especially with respect to environmental sensitizers, cannot be complete because of the presence of patients in whom causative factors have not been identified. However, identification of these factors should be part of the clinical evaluation, as it allows for the implementation of elimination measures.

According to the temporal characteristics of bronchial obstruction, measured using peak expiratory flow rate (PEF), the following are distinguished:

• intermittent asthma, characterized by the presence of rare, occasional respiratory symptoms and concomitant decrease in PEF (over the past year) in combination with normal PEF values and normal/near-normal airway reactivity between episodes of deterioration;
• persistent asthma with characteristic exacerbation and remission phases, variation in daytime and nighttime PEF values, frequent symptom onset, and persistent airway hyperreactivity. Some patients with long-standing persistent asthma and an irreversible obstructive component fail to achieve normal lung function despite intensive glucocorticoid therapy.

The most convenient in practical terms, including when managing such patients during pregnancy, is the classification of the disease by severity. The severity of the patient's condition before treatment can be classified into one of four stages based on the noted clinical signs and lung function indicators.

1. Bronchial asthma of intermittent (episodic) course:
   • asthma symptoms occur less than once a week;
   • night symptoms no more than 2 times a month;
   • short exacerbations (from several hours to several days);
   • there are no symptoms of broncho-obstruction between exacerbations;
   • lung function indicators outside of exacerbation are within normal limits; forced expiratory volume (FEV) in 1 s or PEF > 80% of the expected values;
   • daily fluctuations in PSV or FEV < 20%.
2. Mild persistent bronchial asthma:
   • symptoms of suffocation more than once a week, but less than once a day;
   • exacerbations can disrupt physical activity and sleep;
   • night symptoms of the disease occur more than 2 times a month;
   • FEV or PSV > 80% of predicted value;
   • daily fluctuations in FEV or PSV = 20–30%.
3. Moderate bronchial asthma:
   • daily symptoms of illness;
   • exacerbations disrupt physical activity and sleep;
   • night symptoms of the disease occur more than once a week;
   • daily requirement for short-acting β2-agonists;
   • FEV or PSV from 60 to 80% of the expected values;
   • diurnal fluctuations in FEV or PSV > 30%.
4. Severe bronchial asthma:
   • daily symptoms of illness;
   • frequent exacerbations;
   • frequent night symptoms;
   • limitation of physical activity;
   • daily requirement for short-acting β2-agonists;
   • FEV or PSV < 60% of predicted value;
   • daily fluctuations in PSV > 30%.

If the patient is already receiving treatment, the severity classification should be based on the clinical signs and the amount of medication taken daily. Patients with persistent (despite the treatment corresponding to the given stage) symptoms of mild persistent asthma should be considered as having moderate persistent asthma. And patients with persistent (despite the treatment) symptoms of moderate persistent asthma should be diagnosed as "bronchial asthma, severe persistent course".

Diagnostics bronchial asthma in pregnancy

Evaluation of lung function, especially the reversibility of its impairment, provides the most accurate assessment of airway obstruction. Measurement of airway variability allows for an indirect assessment of airway hyperreactivity.

The most important values for assessing the degree of bronchial obstruction are: the volume of formed expiration in 1 second (FEV1) and the associated forced vital capacity (FVC), as well as PEF. FEV1 and FVC are measured using a spirometer (spirometry). The expected values of the indicators are determined based on the results of population studies based on the patient's age, gender and height. Since a number of diseases, in addition to those causing bronchial obstruction, can lead to a decrease in FEV1, it is useful to use the FEV1 to FVC ratio. With normal lung function, it is > 80%. Lower values suggest bronchial obstruction. An increase in FEV1 by more than 12% indicates the predominance of the functional component of obstruction and confirms the diagnosis of bronchial asthma. Measuring PEF using a peak flow meter (peak flowmetry) allows for home monitoring and an objective assessment of the degree of lung dysfunction over time. The severity of bronchial asthma reflects not only the average level of bronchial obstruction, but also fluctuations in PEF over 24 hours. PEF should be measured in the morning, when the indicator is at its lowest level, and in the evening, when PEF is usually highest. A daily variation in PEF indicators of more than 20% should be considered a diagnostic sign of bronchial asthma, and the magnitude of the deviations is directly proportional to the severity of the disease.

Differential diagnosis

Bronchial asthma is one of the most common causes of respiratory symptoms. However, there are many other diseases with similar symptoms: COPD, cystic fibrosis, obliterating bronchiolitis, tumor or foreign body of the larynx, trachea, bronchi. The main confirmation of the diagnosis of "bronchial asthma" is the detection (preferably by spirometry) of reversible and variable bronchial obstruction.

Treatment bronchial asthma in pregnancy

The main objectives of treating bronchial asthma in pregnant women include normalizing respiratory function, preventing exacerbations of bronchial asthma, eliminating side effects of anti-asthma drugs, and stopping attacks of bronchial asthma, which is considered the key to a proper, uncomplicated pregnancy and the birth of a healthy child.

Therapy for bronchial asthma in pregnant women is carried out according to the same rules as in non-pregnant women. The main principles are increasing or decreasing the intensity of therapy as the severity of the disease changes, taking into account the characteristics of the course of pregnancy, mandatory monitoring of the course of the disease and the effectiveness of the prescribed treatment by peak flowmetry, and the preferred use of inhalation administration of medications.

Medicines prescribed for bronchial asthma are divided into:

• basic - controlling the course of the disease (systemic and inhaled glucocorticoids, cromones, long-acting methylxanthines, long-acting β2-agonists, antileukotriene drugs), they are taken daily, for a long time;
• symptomatic or emergency drugs (short-acting inhaled β2-agonists, anticholinergics, methylxanthines, systemic glucocorticoids) - quickly relieve bronchospasm and its accompanying symptoms: wheezing, a feeling of "tightness" in the chest, cough.

Treatment is selected based on the severity of bronchial asthma, the availability of anti-asthma drugs and the individual living conditions of the patient.

Among β2-adrenomimetics, salbutamol, terbutaline, and fenoterol can be used during pregnancy. Anticholinergics used to treat bronchial asthma in pregnant women include ipratropium bromide in the form of an inhaler or a combined drug, "Ipratropium bromide + fenoterol". Drugs of these groups (both beta2-mimetics and anticholinergics) are often used in obstetric practice to treat the threat of termination of pregnancy. Methylxanthines, which include aminophylline, euphylline, are also used in obstetric practice to treat pregnant women, in particular in the treatment of gestosis. Cromones - cromoglycic acid, used in the treatment of bronchial asthma as a basic anti-inflammatory agent in mild bronchial asthma, have limited use during pregnancy due to their low efficiency, on the one hand, and the need to obtain a rapid therapeutic effect, on the other (taking into account the presence of pregnancy and the risk of development or increase in fetoplacental insufficiency in conditions of an unstable course of the disease). They can be used in patients who have used these drugs with sufficient effect before pregnancy, provided that the disease remains stable during pregnancy. If it is necessary to prescribe basic anti-inflammatory therapy during pregnancy, preference should be given to inhaled glucocorticoids (budesonide).

• In intermittent asthma, daily medication is not recommended for most patients. Treatment of exacerbations depends on the severity. If necessary, a rapid-acting inhaled beta2-agonist is prescribed to relieve asthma symptoms. If severe exacerbations are observed in intermittent asthma, such patients should be treated as patients with moderate persistent asthma.
• Patients with mild persistent asthma require daily medication to maintain disease control. Inhaled glucocorticoids (budesonide 200–400 mcg/day or <500 mcg/day beclomethasone or equivalent) are preferred. Long-acting methylxanthines, cromones, and antileukotrienes may be alternatives.
• In moderate persistent asthma, combinations of inhaled glucocorticoids (budesonide 400–800 mcg/day, or beclomethasone 500–1000 mcg/day or equivalent) and long-acting inhaled beta2-agonists twice daily are prescribed. An alternative to the beta2-agonist in this combination therapy is long-acting methylxanthine.
• Therapy for severe persistent asthma includes high-dose inhaled glucocorticoids (budesonide > 800 mcg/day or > 1000 mcg/day beclomethasone or equivalent) in combination with long-acting inhaled β2-agonists twice daily. An alternative to long-acting inhaled β2-agonists is an oral β2-agonist or long-acting methylxanthine. Oral glucocorticoids may be administered.
• After achieving control of bronchial asthma and maintaining it for at least 3 months, a gradual reduction in the volume of maintenance therapy is carried out, and then the minimum concentration necessary to control the disease is determined.

Along with the direct effect on asthma, such treatment also affects the course of pregnancy and fetal development. First of all, this is the spasmolytic and antiaggregatory effect obtained when using methylxanthines, the tocolytic effect (reduced tone, relaxation of the uterus) when using β2-agonists, immunosuppressive and anti-inflammatory effects when conducting glucocorticoid therapy.

When conducting bronchodilator therapy in patients with a threat of termination of pregnancy, preference should be given to tablet β2-mimetics, which, along with the bronchodilator, will also have a tocolytic effect. In the presence of gestosis, it is advisable to use methylxanthines - euphyllin as a bronchodilator. If systemic use of hormones is necessary, prednisolone or methylprednisolone should be preferred.

When prescribing drug therapy to pregnant women with bronchial asthma, it should be taken into account that most anti-asthmatic drugs have no adverse effects on the course of pregnancy. At the same time, there are currently no drugs with proven safety in pregnant women, because controlled clinical trials on pregnant women are not conducted. The main goal of treatment is to select the minimum necessary doses of drugs to restore and maintain optimal and stable bronchial patency. It should be remembered that the harm from an unstable course of the disease and respiratory failure that develops in this case for the mother and fetus is incomparably higher than the possible side effects of drugs. Rapid relief of exacerbation of bronchial asthma, even with the use of systemic glucocorticoids, is preferable to a long-term uncontrolled or poorly controlled course of the disease. Refusal of active treatment invariably increases the risk of complications for both the mother and the fetus.

During labor, treatment of bronchial asthma should not be stopped. Inhalation therapy should be continued. Women who received oral hormones during pregnancy should receive prednisolone parenterally.

Since the use of β-mimetics during labor is associated with the risk of weakening labor activity, preference should be given to epidural anesthesia at the thoracic level when conducting bronchodilator therapy during this period. For this purpose, puncture and catheterization of the epidural space in the thoracic region at the level of ThVII–ThVIII are performed with the introduction of 8–10 ml of 0.125% bupivacaine solution. Epidural anesthesia allows achieving a pronounced bronchodilator effect and creating a kind of hemodynamic protection. Deterioration of fetoplacental blood flow against the background of the introduction of local anesthetic is not observed. At the same time, conditions are created for spontaneous delivery without excluding pushing in the second stage of labor, even in severe cases of the disease, disabling patients.

Exacerbation of bronchial asthma during pregnancy is an emergency that threatens not only the life of the pregnant woman, but also the development of intrauterine hypoxia of the fetus up to its death. In this regard, treatment of such patients should be carried out in a hospital setting with mandatory monitoring of the function of the fetoplacental complex. The basis of treatment of exacerbations is the introduction of β2-agonists (salbutamol) or their combination with an anticholinergic drug (ipratropium bromide + fenoterol) through a nebulizer. Inhalation administration of glucocorticosteroids (budesonide - 1000 mcg) through a nebulizer is an effective component of combination therapy. Systemic glucocorticosteroids should be included in the treatment if after the first nebulizer administration of β2-agonists, no persistent improvement is achieved or the exacerbation developed against the background of taking oral glucocorticosteroids. Due to the peculiarities occurring in the digestive system during pregnancy (longer gastric emptying), parenteral administration of glucocorticosteroids is preferable to taking drugs per os.

Bronchial asthma is not an indication for termination of pregnancy. In case of unstable course of the disease, severe exacerbation, termination of pregnancy is associated with a high risk to the patient's life, and after the exacerbation is stopped and the patient's condition is stabilized, the question of the need to terminate pregnancy disappears altogether.

Delivery of pregnant women with bronchial asthma

Delivery of pregnant women with a mild course of the disease with adequate pain relief and corrective drug therapy does not present any difficulties and does not worsen the condition of the patients.

In most patients, labor ends spontaneously (83%). Among the complications of labor, the most common are rapid labor (24%), prelabor rupture of membranes (13%). In the first period of labor - labor anomalies (9%). The course of the second and third periods of labor is determined by the presence of additional extragenital, obstetric pathology, features of the obstetric and gynecological history. In connection with the available data on the possible bronchospastic effect of methylergometrine, when preventing bleeding in the second period of labor, preference should be given to intravenous oxytocin. Labor, as a rule, does not worsen the condition of patients. With adequate treatment of the underlying disease, careful management of labor, careful observation, pain relief and prevention of purulent-inflammatory diseases, these patients do not experience complications in the postpartum period.

However, in severe cases of the disease, which disables patients, with a high risk of development or with the presence of respiratory failure, childbirth becomes a serious problem.

In pregnant women with severe bronchial asthma or uncontrolled course of moderate bronchial asthma, asthmatic status during this pregnancy, exacerbation of the disease at the end of the third trimester, delivery is a serious problem due to significant violations of the function of external respiration and hemodynamics, a high risk of intrauterine fetal distress. This contingent of patients is at risk of developing a severe exacerbation of the disease, acute respiratory and cardiac failure during delivery.

Given the high degree of infectious risk, as well as the risk of complications associated with surgical trauma in severe illness with signs of respiratory failure, the method of choice is planned delivery through the natural birth canal.

In case of vaginal delivery, before labor induction, puncture and catheterization of the epidural space in the thoracic region at the level of ThVIII–ThIX are performed with the introduction of a 0.125% solution of marcaine, which provides a pronounced bronchodilator effect. Then labor induction is performed by amniotomy. The behavior of the woman in labor during this period is active.

With the onset of regular labor, labor pain relief begins with epidural anesthesia at the L1–L2 level.

The introduction of a prolonged-action anesthetic in a low concentration does not limit the woman's mobility, does not weaken the pushing in the second stage of labor, has a pronounced bronchodilator effect (increase in the forced vital capacity of the lungs - FVC, FEV1, POS) and allows for the creation of a kind of hemodynamic protection. There is an increase in the stroke output of the left and right ventricles. Changes in fetal blood flow are noted - a decrease in the resistance to blood flow in the vessels of the umbilical cord and the aorta of the fetus.

Against this background, spontaneous delivery becomes possible without excluding pushing in patients with obstructive disorders. In order to shorten the second stage of labor, an episiotomy is performed. In the absence of sufficient experience or technical capabilities for performing epidural anesthesia at the thoracic level, delivery should be performed by cesarean section. Due to the fact that endotracheal anesthesia represents the greatest risk, epidural anesthesia is the method of choice for pain relief during cesarean section.

Indications for operative delivery in pregnant women with bronchial asthma are:

• the presence of signs of cardiopulmonary failure after the relief of a prolonged severe exacerbation or asthmatic status;
• history of spontaneous pneumothorax;
• Also, a cesarean section can be performed for obstetric indications (such as the presence of an insolvent scar on the uterus after a previous cesarean section, a narrow pelvis, etc.).

Prevention

Bronchial asthma is the most common serious disease complicating pregnancy. Asthma may debut or be diagnosed for the first time during pregnancy, and the severity of the course may change as pregnancy progresses. About 1/3 of women report an improvement in their condition, 1/3 do not note any change in the course of the disease during pregnancy, and 1/3 report a worsening of the condition. More than half of pregnant women experience an exacerbation of the disease during pregnancy. Moreover, exacerbations most often occur in the second trimester of pregnancy. During a subsequent pregnancy, 2/3 of women experience the same changes in the course of the disease as during the first pregnancy.

Causes of complicated pregnancy and perinatal pathology

The development of pregnancy complications and perinatal pathology is associated with the severity of bronchial asthma, the presence of exacerbations of bronchial asthma during pregnancy and the quality of the therapy. The number of pregnancy complications increases proportionally to the severity of the disease. In severe bronchial asthma, perinatal complications are recorded 2 times more often than in mild asthma. It is important to note that in women who had exacerbations of asthma during pregnancy, perinatal pathology is encountered 3 times more often than in patients with a stable course of the disease.

The immediate causes of complicated pregnancy in patients with bronchial asthma include:

• changes in respiratory function (hypoxia);
• immune disorders;
• disturbances of hemostatic homeostasis;
• metabolic disorders.

Changes in FVD, directly related to the quality of treatment during pregnancy and the severity of bronchial asthma, are considered the main cause of hypoxia. They can contribute to the development of fetoplacental insufficiency.

Immune disorders, the main meaning of which lies in the shift of T-helpers differentiation towards Th2 and, accordingly, the predominance of Th2-dependent effector processes of immune inflammation with the participation of a number of cytokines (IL4, IL5, IL6, IL10) and the effect on antibody production in B-lymphocytes (IgE), contribute to the development of autoimmune processes [antiphospholipid syndrome (APS)], a decrease in antiviral antimicrobial protection, as well as a high frequency of inflammatory diseases of the pelvic organs. When studying the microbiocenosis of the birth canal, normal microflora is determined only in 10% of pregnant women with bronchial asthma. Candidiasis is detected in 35% of patients, and mixed viral-bacterial flora is found in 55% of pregnant women. The above features are the main causes of frequently observed intrauterine infection in pregnant women with bronchial asthma. Autoimmune processes, in particular APS, during pregnancy lead to damage to the placental tissue, its vascular bed by immune complexes, resulting in placental insufficiency and intrauterine growth retardation. In such situations, pregnancy may end in the death of the fetus or its premature termination.

Hypoxia on the one hand and damage to the vascular wall on the other hand lead to a disorder of hemostatic homeostasis - the development of chronic DIC syndrome, which is manifested by accelerated blood clotting, increased circulation of soluble fibrin monomer complexes, increased spontaneous and decreased induced platelet aggregation and leads to impaired microcirculation in the placenta.

It should be noted that another important reason for the formation of placental insufficiency in women with bronchial asthma is metabolic disorders. A number of studies have shown that patients with bronchial asthma have increased lipid peroxidation, decreased antioxidant activity of the blood, and decreased activity of intracellular enzymes. In severe and unstable bronchial asthma, the most significant homeostasis disorders are observed, which are the main causes of complicated pregnancy.

In this regard, preparation of patients with bronchial asthma for pregnancy, their thorough examination during pregnancy, as well as adequate treatment of the disease, ensuring the absence of exacerbations and clinical manifestations of asthma, are the key to the physiological course of pregnancy and the birth of a healthy child.

The most favorable pregnancy outcome for the mother and fetus in bronchial asthma is ensured by quality medical care both at the pre-pregnancy preparation stage and during pregnancy.

Pre-conception preparation

Pregnant women with COPD are recommended to plan their pregnancy with pre-gravid preparation, which consists of examination by an obstetrician-gynecologist and a pulmonologist. The pulmonologist conducts a study of the functions of external respiration, assesses the patient's condition to determine the required volume of specific basic therapy for pulmonary disease in order to compensate it as much as possible before pregnancy. One of the mandatory links in monitoring the effectiveness of the treatment is keeping a peak flowmetry diary by the pregnant woman.

A significant number of pregnant women (74%) with bronchial asthma are diagnosed with STIs, and the incidence of intrauterine infection reaches 30%. In this regard, during a gynecological examination, special attention should be paid to the examination of women planning pregnancy for chlamydia, ureaplasmosis, mycoplasmosis, etc., and virological examination. If an infection is detected, a course of antibacterial and antiviral therapy is administered.

Patients with bronchial asthma should plan pregnancy taking into account possible seasonal exacerbations of the lung disease.

A mandatory point is the exclusion of both active and passive smoking. Asthma in smokers is more severe, and exacerbations are more pronounced and require larger doses of anti-inflammatory drugs.

Given the unfavorable effect of chronic non-specific lung diseases on the course of pregnancy, women suffering from bronchopulmonary pathology should be under constant supervision of a pulmonologist with the onset of pregnancy. Due to the fact that the leading role in the development of obstetric and perinatal pathology is played not so much by the severity of the disease, but by the absence of its exacerbations, the main task of the pulmonologist is to conduct specific basic therapy of the pulmonary disease in an adequate volume in order to maximize its compensation.

Examination of pregnant women

Examination of pregnant women with bronchial asthma should be carried out in specialized hospitals and maternity homes that have the ability to carry out modern instrumental and biochemical studies in addition to consultation with a pulmonologist.

It is necessary to study the respiratory function test, central hemodynamics, and blood coagulation parameters. Bacteriological and virological examination (cervical canal, vagina, pharynx, nose) is an extremely important measure due to the high frequency of urogenital infection in these patients, as well as a significant proportion of intrauterine infection in the structure of perinatal pathology in their newborns. Given the high risk of developing intrauterine fetal distress, pregnant women with bronchial asthma require a thorough study of the fetoplacental system function, including ultrasound diagnostics (fetometry, fetal hemodynamics assessment), hormone testing (placental lactogen, estriol, α-fetoprotein, progesterone, cortisol), and cardiomonitoring (CTG).

The study of homeostasis allows, along with the decision on the required volume of anticoagulant and antiplatelet therapy, to assess the risk of perinatal complications. Particular attention should be paid to identifying signs of fibrinogen consumption: monitoring the dynamics of changes in its concentration, identifying soluble fibrin monomer complexes (SFMC), determining the antithrombin activity of the blood. It is necessary to assess the state of the platelet link of blood coagulation due to a possible violation of the functional state of platelets in pregnant women with bronchial asthma. It is advisable to study not only induced, but also spontaneous aggregation, since their comparison provides a more complete assessment of the state of platelets.

Due to the high frequency of urogenital infections in pregnant women with COPD, along with the usual bacterioscopic examination of smears, such patients need to undergo detailed bacteriological and virological examinations in order to diagnose a possible infection of the urogenital tract and prescribe timely therapy.

Studying individual parameters of the immune system can also be of great help in preventing and treating pregnancy complications in patients with chronic non-specific lung diseases. Detection of antiphospholipid antibodies (lupus anticoagulant) and, if possible, the nature of the dysfunction of the interferon system allows for more effective prediction and drug therapy of obstetric complications.

Examination of pregnant women with bronchial asthma should be carried out at the first visit to the doctor, at 18–20, 28–32 weeks and in full-term pregnancy before delivery, as well as after completion of the course of therapy for pregnancy complications, to assess its effectiveness and clarify the tactics of further management.

Prediction of obstetric and perinatal pathology in pregnant women with bronchial asthma

Antenatal prognosis of the risk of birth of a child with perinatal pathology is carried out by identifying a risk group, which should include pregnant women with exacerbation of the disease during pregnancy, the addition of gestosis, with impaired FVD, central hemodynamics, homeostasis, with a decrease in the concentration of placental lactogen, estriol, cortisol below the 40th percentile level at 28-32 weeks of pregnancy. The birth of a child with perinatal pathology can be expected with a decrease in the peak expiratory flow rate < 55% of the expected value. The accuracy of the rule is 86%. In the presence of gestosis in a pregnant woman with bronchial asthma and registration of changes in PEF, perinatal pathology can be predicted with an accuracy of up to 94%. With a combination of a decrease in PEF less than 55% and FVC less than 63% of the expected values, perinatal pathology develops in all pregnant women. In the absence of a decrease in the elevated concentration of IgE during treatment in pregnant women with bronchial asthma, the development of a complicated pregnancy can be expected with 86% accuracy.

Drug prevention of obstetric and perinatal complications

Based on the main pathogenetic links in the development of pregnancy complications in patients with COPD, drug prevention of obstetric and perinatal complications should include treatment of the underlying pulmonary disease, optimization of oxidation-reduction processes (use of Essentiale, vitamin E - to reduce the intensity of lipid peroxidation, stabilize the structural and functional properties of cell membranes, normalize the functional state of erythrocytes and improve fetal trophism, Actovegin, which improves tissue supply with oxygen and glucose, activates oxidative phosphorylation enzymes, normalizes the acid-base state of the cell), immunocorrection (Viferonotherapy, which helps reduce infectious complications and affects the pathogenetic mechanisms of bronchial asthma development, Metipred when signs of APS are detected) and treatment of chronic DIC syndrome (heparin, which activates the antithrombin system and thereby normalizes hemostasis parameters, and also binds circulating immune complexes; antiplatelet agents - curantil, trental, euphyllin, which increase the synthesis of prostacyclin by the vascular wall and reduce intravascular platelet aggregation). If an elevated level of IgE, markers of autoimmune processes (lupus anticoagulant, antibodies to hCG) with signs of intrauterine fetal distress and the lack of sufficient effect from conservative therapy are detected, therapeutic plasmapheresis is indicated. 4-5 procedures are performed 1-2 times a week with the removal of up to 30% of the circulating plasma volume.

[ 11 ], [ 12 ], [ 13 ], [ 14 ], [ 15 ], [ 16 ]