A prospective study of respiratory viral infection in pregnant women with and without asthma

Complex interplays: Asthma management and maternal‑fetal outcomes in pregnancy (Review)

Asthma, a common chronic respiratory condition, poses unique challenges in pregnancy, impacting both maternal and fetal health. Of note, 8-13% of pregnant women suffer from asthma, a condition that can worsen, stabilize, or improve during pregnancy. These fluctuations necessitate a nuanced management strategy to ensure the health of both the mother and fetus. Adverse outcomes, such as preeclampsia, gestational diabetes and increased cesarean delivery rates are associated with poorly controlled asthma. From a fetal perspective, the risks include preterm birth and a low birth weight. Physiological changes in pregnancy, such as an increased tidal volume and altered drug metabolism due to increased blood volume, complicate the management of asthma. The safety of asthma medications during pregnancy remains a significant concern, with ongoing research into their teratogenic effects. Recent advancements in treatment include the development of biologics and the increased use of personalized medicine, integrating pharmacogenomics and immunological profiling to tailor treatments to individual needs. Digital health tools have also emerged, enabling improved patient monitoring and management. The present review highlights the complex interplay between asthma management and pregnancy outcomes, advocating for comprehensive care approaches that consider the dynamic physiological changes during pregnancy. It underscores the need for ongoing research into the safety of medication and innovative therapeutic strategies to improve health outcomes for pregnant women with asthma and their babies.

Breathing for Two: Asthma Management, Treatment, and Safety of Pharmacological Therapy during Pregnancy

The primary objectives of asthma management during pregnancy are to achieve adequate symptom control, reduce the risk of acute exacerbations, and maintain normal pulmonary function, all of which contribute to ensuring the health and well-being of both the mother and the baby. The Global Initiative for Asthma (GINA) recommends that pregnant women with asthma continue using asthma medications throughout pregnancy, as the benefits of well-controlled asthma for both the mother and fetus outweigh the potential risks of medication side effects, poorly controlled asthma, and exacerbations. The classification of asthma medications by the US Food and Drug Administration (FDA) into categories A, B, C, D, and X is no longer applied. Instead, the potential benefits and risks of each medication during pregnancy and lactation are considered individually. The use of medications to achieve good asthma control and prevent exacerbations during pregnancy is justified, encompassing inhaled corticosteroids (ICS), some leukotriene receptor antagonists (LTRA), short-acting beta-2 agonists (SABA), long-acting beta-2 agonists (LABA), short-acting muscarinic antagonists (SAMA), long-acting muscarinic antagonists (LAMA), and, recently, biological therapies, even in the absence of definitive safety data during pregnancy.

Non-allergic factors that influence asthma control in pregnancy

INTRODUCTION

Numerous factors may influence the asthma course during pregnancy, potentially elevating the risk of specific pregnancy complications. This study aimed to evaluate non-allergic factors influencing asthma and to assess perinatal outcomes between asthmatic and non-asthmatic pregnancies in the population of the Pomeranian Voivodeship region of Poland.

METHODS

The mixed cohort study was performed with 83 pregnant asthmatic patients aged 18-38 years. The control group consisted of 83 patients without asthma diagnosis or symptoms. A specially designed questionnaire was used to evaluate asthma course and perinatal outcomes. An Asthma Control Test (ACT) adapted for pregnancy was performed on enrollment. Asthma severity was assessed according to GINA guidelines.

RESULTS

In 19 cases (22.80%), patients quit their regular treatment after pregnancy was confirmed. Respiratory tract infection occurred in 23 patients (27.71%) and had been statistically significantly more frequent among patients with partially and uncontrolled asthma (χ2=8.504, p<0.05). No statistically significant difference was found between infection episodes and perinatal complications. The incidence of cesarean section was significantly higher among patients with asthma (χ2=16.37, p<0.01), particularly in patients with severe asthma (χ2=7.07, p<0.05) and uncontrolled asthma (χ2=6.7, p<0.05). Apgar score was statistically significantly lower in patients with severe asthma (χ2=20.37, p<0.05).

CONCLUSIONS

Respiratory tract infections and adequate asthma treatment are the most important modifiable factors in preventing perinatal complications associated with asthma.

Chinese expert consensus on the diagnosis, treatment, and management of asthma in women across life

Background

The epidemiology and severity of asthma vary by sex and age. The diagnosis, treatment, and management of asthma in female patients are quite challenging. However, there is hitherto no comprehensive and standardized guidance for female patients with asthma.

Methods

Corresponding search strategies were determined based on clinical concerns regarding female asthma. Search terms included "sex hormones and lung development", "sex hormone changes and asthma", "hormones and asthma immune response", "women, asthma", "children, asthma", "puberty, asthma", "menstruation, asthma", "pregnancy, asthma", "lactation, asthma", "menopause, asthma", "obesity, asthma", and "women, refractory, severe asthma". Literature was retrieved from PubMed/Medline, Embase, Cochrane Library, China Biology Medicine disc, China National Knowledge Infrastructure, Wanfang Data with the search date of July 30, 2022 as the last day. This consensus used the Grading of Recommendations Assessment, Development, and Evaluation to evaluate the strength of recommendation and quality of evidence.

Results

We collected basic research results and clinical evidence-based medical data and reviewed the effects of sex hormones, classical genetics, and epigenetics on the clinical presentation and treatment response of female patients with asthma under different environmental effects. Based on that, we formulated this expert consensus on the management of female asthma throughout the life cycle.

Conclusions

This expert consensus on the management of asthma in women throughout the life cycle provides diagnosis, treatment, and research reference for clinical and basic medical practitioners.

Treatable traits in asthma during pregnancy: a call for a shift towards a precision-based management approach

Asthma is the most common chronic medical condition in pregnancy. Asthma exacerbations in pregnancy are unpredictable, and are associated with adverse maternal and fetal perinatal outcomes such as preterm birth and low birthweight. Goals of asthma management in pregnancy are to establish effective asthma control and prevent exacerbations. Optimising the management of asthma in pregnancy is an important goal of practice and future research.Treatable traits is a precision medicine paradigm proposed for the management of airways diseases, which holistically addresses the complexity and heterogeneity of airways disease. It is an individualised treatment approach that aims to improve outcomes. This makes treatable traits well suited for pregnant women with asthma, who have a high prevalence of obesity, mental health conditions, poor symptom perception and suboptimal asthma management skills including low treatment adherence. These traits are measurable and treatable. In this review, we explore current knowledge on the burden of asthma, maternal and perinatal consequences of asthma during pregnancy, the treatable traits paradigm, the prevalence of treatable traits in pregnant women with asthma, and consider how the treatable traits paradigm can be integrated into the management of asthma in pregnancy.

Inflammatory and antiviral responses to influenza A virus infection are dysregulated in pregnant mice with allergic airway disease

Influenza A virus (IAV) infections are increased during pregnancy especially with asthma as a comorbidity, leading to asthma exacerbations, secondary bacterial infections, intensive care unit admissions, and mortality. We aimed to define the processes involved in increased susceptibility and severity of IAV infections during pregnancy, especially with asthma. We sensitized mice to house dust mite (HDM), induced pregnancy, and challenged with HDM to induce allergic airway disease (AAD). At midpregnancy, we induced IAV infection. We assessed viral titers, airway inflammation, lung antiviral responses, mucus hypersecretion, and airway hyperresponsiveness (AHR). During early IAV infection, pregnant mice with AAD had increased mRNA expression of the inflammatory markers Il13 and IL17 and reduced mRNA expression of the neutrophil chemoattractant marker Kc. These mice had increased mucous hyperplasia and increased AHR. miR155, miR574, miR223, and miR1187 were also reduced during early infection, as was mRNA expression of the antiviral β-defensins, Bd1, Bd2, and Spd and IFNs, Ifnα, Ifnβ, and Ifnλ. During late infection, Il17 was still increased as was eosinophil infiltration in the lungs. mRNA expression of Kc was reduced, as was neutrophil infiltration and mRNA expression of the antiviral markers Ifnβ, Ifnλ, and Ifnγ and Ip10, Tlr3, Tlr9, Pkr, and Mx1. Mucous hyperplasia was still significantly increased as was AHR. Early phase IAV infection in pregnancy with asthma heightens underlying inflammatory asthmatic phenotype and reduces antiviral responses.NEW & NOTEWORTHY Influenza A virus (IAV) infection during pregnancy with asthma is a major health concern leading to increased morbidity for both mother and baby. Using murine models, we show that IAV infection in pregnancy with allergic airway disease is associated with impaired global antiviral and antimicrobial responses, increased lung inflammation, mucus hypersecretion, and airway hyperresponsiveness (AHR). Targeting specific β-defensins or microRNAs (miRNAs) may prove useful in future treatments for IAV infection during pregnancy.

[Diagnosis and treatment of asthma: a guideline for respiratory specialists 2023 - published by the German Respiratory Society (DGP) e. V.]

The management of asthma has fundamentally changed during the past decades. The present guideline for the diagnosis and treatment of asthma was developed for respiratory specialists who need detailed and evidence-based information on the new diagnostic and therapeutic options in asthma. The guideline shows the new role of biomarkers, especially blood eosinophils and fractional exhaled NO (FeNO), in diagnostic algorithms of asthma. Of note, this guideline is the first worldwide to announce symptom prevention and asthma remission as the ultimate goals of asthma treatment, which can be achieved by using individually tailored, disease-modifying anti-asthmatic drugs such as inhaled steroids, allergen immunotherapy or biologics. In addition, the central role of the treatment of comorbidities is emphasized. Finally, the document addresses several challenges in asthma management, including asthma treatment during pregnancy, treatment of severe asthma or the diagnosis and treatment of work-related asthma.

Asthma and Respiratory Infections From Birth to Young Adulthood

We applied data from a population-based prospective study, the Espoo Cohort Study (n = 2,568), to identify the potential susceptibility of persons with asthma to respiratory tract infections (RTIs). Information on the occurrence of asthma and both upper respiratory tract infections (URTIs) and lower respiratory tract infections (LRTIs) was collected with a questionnaire at baseline and at the 6-year and 20-year follow-up studies, and from the Finnish national health registries. We estimated age- and sex-specific incidence rate differences (IRDs) and incidence rate ratios (IRRs) by applying negative binomial regression. Meta-regression was used to summarize the age-specific IRRs from childhood to 27 years of age. Individuals with asthma at any age during the follow-up period had increased risks of both URTIs (adjusted IRD = 72.6 (95% confidence interval (CI): 50.6, 94.7) per 100 person-years; adjusted IRR = 1.27 (95% CI: 1.20, 1.35)) and LRTIs (adjusted IRD = 25.5 (95% CI: 17.9, 33.1); adjusted IRR = 2.87 (95% CI: 2.33, 3.53)) from childhood to young adulthood. In young adulthood, the association between asthma and URTIs was stronger in women than in men, while such an association was not detected for LRTIs. This analysis provides strong evidence that persons with asthma experience more RTIs from preschool age to young adulthood than do those without asthma. Thus, they constitute a susceptible population for RTIs. Women with asthma are at especially high risk.

Asthma in pregnancy

Background: Asthma is a frequent and potentially life-threatening disease that complicates many pregnancies. There are extensive data with regard to the diagnosis and treatment of asthma during pregnancy. Medical providers require an up-to-date summary of the critical aspects of asthma management during pregnancy. Objective: This review aimed to summarize the available data from clinical trials, cohort studies, expert opinions, and guideline recommendations with regard to asthma in pregnancy. Methods: A search through PubMed was conducted by using keywords previously mentioned and MeSH (Medical Subject Headings) terminology. Clinical trials, observational studies, expert opinions, guidelines, and other reviews were included. The quality of the studies was assessed, and data were extracted and summarized. Results: Asthma worsens in ∼40% of pregnant women, which can be associated with maternal and fetal complications. Physiologic changes in the respiratory, cardiovascular, and immune systems during pregnancy play a critical role in the manifestations of asthma. The diagnosis and the treatment of asthma are similar to that of patients who are not pregnant. Nonetheless, concern for fetal malformations, preterm birth, and low birth weight must be considered when managing pregnant patients with asthma. Importantly, cornerstones of the pharmacotherapy of asthma seem to be safe during pregnancy. Conclusion: Asthma in pregnancy is associated with adverse outcomes. Roadblocks to management include associated comorbidities, medication nonadherence, atopy, lack of education, and smoking habits. These need to be acknowledged and addressed for successful asthma management during pregnancy.

Beliefs about medicines and adherence to asthma medications during pregnancy

OBJECTIVE

Discontinuation of, and non-adherence to, inhaled corticosteroids (ICS) for asthma treatment is a significant issue in pregnancy. This study characterized beliefs about medicines in pregnant women with asthma and investigated associations with ICS adherence.

METHODS

Pregnant women with relatively mild asthma (n = 302) were grouped according to ICS use and self-reported adherence (≥80% doses taken). They completed questions about dislike of asthma medications and the validated Beliefs about Medicines Questionnaire (BMQ), which consists of ten questions about asthma medicines ("necessity" questions about maintaining health, or "concern" questions about adverse effects), and eight general medicine questions, scored on five-point Likert scales. The Necessity Concerns differential (N-C) was calculated, with positive scores indicating that the patient perceives the benefits of medicines to outweigh the risks.

RESULTS

ICS was used by 87 (29%) women, with 49 (56%) self-reporting adherence. Of the 22% who disliked taking asthma medications during pregnancy, 20% had the belief that the medication was unsafe. ICS users had a significantly higher BMQ necessity score and higher necessity-concern differential score than nonusers; when adjusted for covariates, ICS non-adherence was associated with a lower necessity score (p = 0.015). Women adherent to ICS were more likely to agree to "my health at present depends on my asthma medication" compared to non-adherent ICS users.

CONCLUSIONS

ICS non-adherence was not associated with having relatively more concerns about asthma medicines; however, ICS users were more likely to perceive that the benefits of medication use outweighed any risks. Interventions to improve asthma medication adherence in pregnancy are needed.

Asthma in pregnancy - Management, maternal co-morbidities, and long-term health

Asthma is the most prevalent chronic disease in pregnancy, and as symptoms can change with pregnancy, and exacerbations of asthma are common, regular review of asthma symptoms, the provision of self-management education, and appropriate medication use are the hallmarks of management. Co-morbidities are also prevalent among pregnant women with asthma, with obesity, gestational diabetes, hypertension, rhinitis, depression, and anxiety, more common among women with asthma than women without asthma. Less is known about reflux, obstructive sleep apnoea and vocal cord dysfunction, along with nutritional deficiencies to iron and vitamin D. Maternal asthma impacts the offspring's long-term health, particularly in increasing the risk of early life wheeze and asthma in childhood. While breastfeeding may modify the risk of infant wheeze, less is known about the mechanisms involved. More research is needed to further understand the relationship between asthma in pregnancy and the risk of poor neurodevelopmental outcomes, such as autism.

Vulnerability for Respiratory Infections in Asthma Patients: A Systematic Review

Asthma is a non-communicable and long-term condition affecting children and adults. The air passages in the lungs become narrow due to inflammation and tightening of the muscles around the small airways. Symptoms of asthma are intermittent and include cough, wheeze, shortness of breath, and chest tightness. Asthma is very often underdiagnosed and under-treated in many regions, especially in developing countries. While many studies show that viral infections can precipitate asthmatic attacks, very few studies have been conducted to see if history or current asthmatic attack increases the risk of viral infections. Our study aims to determine the predisposition of asthmatics to develop various viral infections and susceptibility toward certain viruses that cause upper respiratory tract infections.

We performed a literature review of both published and unpublished articles. We included case reports, case series, reviews, clinical trials, cohort, and case-control studies, written only in English. Commentaries, letters to editors, and book chapters were excluded. Our initial search yielded 948 articles, of which 826 were rejected either because they were irrelevant or because they did not meet our inclusion criteria. We finally screened 122 abstracts and identified 24 relevant articles.

People with a history of asthma have an abnormal innate immune response, making them potentially slower in clearing the infection and susceptible to both infections and virus-induced cell cytotoxicity. Also, in these studies, deficiencies in the interferon alpha response of peripheral blood mononuclear cells and plasmacytoid dendritic cells have been observed in asthmatics, both adults and children. Asthmatics with a viral infection usually present with an acute exacerbation of asthma, represented by dyspnea and cough, with other prodromal symptoms including vomiting and general malaise.

The review includes an update on the relevance of dysregulated immune pathways in causing viral infections in asthmatic populations. It focuses on the evidence to suggest that people with asthma are at increased risk of viral infection, and viral infections in turn are known to precipitate and worsen the asthmatic status, making this a vicious cycle. The authors also suggest that further studies be undertaken to elucidate the pathophysiology and identify the critical therapeutic steps to break this vicious cycle and improve the quality of life for people with asthma.

Seasonal variations in the occurrence of preeclampsia and potential implication of upper respiratory infections in South Korea

The aim of this study was to examine the effect of seasonal changes on the incidence of preeclampsia (PE) in South Korea and East Asian populations, and to evaluate the relationship between upper respiratory infection (URI) during pregnancy and the development of PE. This cohort study included women who had singleton births between 2012 and 2018 in South Korea. A total of 548,080 first singleton births were analyzed, and 9311 patients (1.70%) were diagnosed with PE. Multivariate analysis showed that older age (≥ 30 years old), low income, residing in the southern part of South Korea, history of cigarette smoking, heavy drinking, higher body mass index, hypertension, or diabetes mellitus were risk factors for PE. Univariate analysis showed that URI was associated with the incidence of PE (P = 0.0294). However, this association was not statistically significant in the multivariate analysis (aOR 1.01; 95% CI 0.95-1.07). After adjusting for confounding variables, the occurrence of PE was the highest in December (aOR 1.21; 95% CI 1.10-1.34) and lowest in July and August. This study demonstrated that there are seasonal variations in the occurrence of PE in South Korea. Moreover, URI may be associated with the development of PE.

Personalized Treatment of Asthma: The Importance of Sex and Gender Differences

An individual's sex (nominally male or female, based on biological attributes) and gender (a complex term referring to socially constructed roles, behaviors, and expressions of identity) influence the clinical course of asthma in several ways. The physiologic development of the lungs and effects of sex hormones may explain why more boys than girls have asthma, and after puberty, more women than men have asthma. Female sex hormones have an impact throughout the life span and are associated with poor asthma control. Gender may influence exposure to asthma triggers, and sex and gender can influence the prevalence of comorbidities and interactions with health care professionals. Despite widely reported sex- and gender-based differences in asthma and asthma management, these issues frequently are not considered by health care professionals. There is also inconsistency regarding the use of "sex" and "gender" in scientific discourse; research is needed to define sex- and gender-based differences better and how they might interact to influence asthma outcomes. This review outlines the impact an individual's sex and gender can have on the pathogenesis, clinical course, diagnosis, treatment, and management of asthma.

Postpartum Respiratory Depression

Postpartum respiratory depression is a complex, multifactorial issue that encompasses a patient's baseline preexisting conditions, certain pregnancy-specific conditions or complications, as well as the iatrogenic element of various medications given in the peripartum period. In this review, we discuss many of these factors including obesity, sleep-disordered breathing, chronic lung disease, neuromuscular disorders, opioids, preeclampsia, peripartum cardiomyopathy, postpartum hemorrhage, amniotic fluid embolism, sepsis, acute respiratory distress syndrome (ARDS), and medications such as analgesics, sedatives, anesthetics, and magnesium. Current recommendations for screening, treatment, and prevention are also discussed.

Nonrespiratory Comorbidities in Asthma

Asthma is a chronic heterogeneous airway disease. Common comorbid conditions are often disproportionately present in severe asthma. Optimal care of patients with asthma requires the recognition and treatment of these comorbid conditions. This review outlines the pathophysiological mechanisms between nonrespiratory comorbid conditions and asthma and their effect on asthma outcomes. They include: type 2 diabetes mellitus, hypertension, atherosclerotic cardiovascular disease, adrenal and thyroid gland diseases, pregnancy, osteoporosis, adverse effects from medications, and mental health disorders. Studies indicate how poor glycemic control of type 2 diabetes mellitus is associated with not only greater health care utilization but poorer asthma outcomes. Also, a large health care claims database indicates that a substantial proportion of pregnant women have uncontrolled asthma and are prescribed suboptimal controller therapy. Additional data about these nonrespiratory comorbidities and medications known to benefit both nonrespiratory comorbidities and asthma are necessary.

COVID-19 prevalence, symptoms, and sociodemographic disparities in infection among insured pregnant women in Northern California

BACKGROUND

Research on COVID-19 during pregnancy has mainly focused on women hospitalized for COVID-19 or other reasons during their pregnancy. Little is known about COVID-19 in the general population of pregnant women.

OBJECTIVE

To describe the prevalence of COVID-19, symptoms, consequent healthcare use, and possible sources of COVID-19 exposure among a population-based sample of pregnant women residing in Northern California.

METHODS

We analyzed data from 19,458 members of Kaiser Permanente Northern California who were pregnant between January 2020 and April 2021 and responded to an online survey about COVID-19 testing, diagnosis, symptoms, and their experiences during the COVID-19 pandemic. Medical diagnosis of COVID-19 during pregnancy was defined separately by self-report and by documentation in electronic health records (EHR). We examined relationships of COVID-19 with sociodemographic factors, underlying comorbidities, and survey measures of COVID-19-like symptoms, consequent healthcare utilization, and possible COVID-19 exposures.

RESULTS

Among 19,458 respondents, the crude prevalence of COVID-19 was 2.5% (n = 494) according to self-report and 1.4% (n = 276) according to EHR. After adjustment, the prevalence of self-reported COVID-19 was higher among women aged <25 years compared with women aged ≥35 years (prevalence ratio [PR], 1.75, 95% CI: 1.23, 2.49) and among Hispanic women compared with White women (PR, 1.91, 95% CI: 1.53, 2.37). Prevalence of self-reported COVID-19 was higher among women affected by personal or partner job loss during the pandemic (PR, 1.23, 95% CI: 1.02, 1.47) and among women living in areas of high vs. low neighborhood deprivation (PR, 1.74, 95% CI: 1.33, 2.27). We did not observe differences in self-reported COVID-19 between women with and without underlying comorbidities. Results were similar for EHR-documented COVID-19. Loss of smell or taste was a unique and common symptom reported among women with COVID-19 (42.3% in self-reported; 54.0% in EHR-documented). Among women with symptomatic COVID-19, approximately 2% were hospitalized, 71% had a telehealth visit, and 75% quarantined at home. Over a third of women with COVID-19 reported no known exposure to someone with COVID-19.

CONCLUSIONS

Observed COVID-19 prevalence differences by sociodemographic and socioeconomic factors underscore social and health inequities among reproductive-aged women. Women with COVID-19 reported unique symptoms and low frequency of hospitalization. Many were not aware of an exposure to someone with COVID-19.

Contemporary management and treatment strategies for asthma during pregnancy

Introduction: Asthma is one of the most common conditions that afflict pregnant women. Because uncontrolled asthma in pregnancy affects both maternal and offspring outcomes, careful attention to maintaining control of asthma symptoms throughout pregnancy is of critical importance.Areas Covered: Using a search of PUBMED/MEDLINE for 'asthma and pregnancy,' this article will review the current literature regarding epidemiology and course of asthma in pregnancy, the effects of uncontrolled asthma on both the mother and offspring, and provide an overview of the management, both non-pharmacologic and pharmacologic, of asthma in pregnancy.Expert Opinion: There is a lack of adequate safety information for most medications taken during pregnancy. Future research might allow better methods to predict which women will experience worsening during pregnancy. For now, surveillance systems like pregnancy registries or observational cohort studies can provide safety information for medications used during pregnancy.

Longitudinal Analysis of Lung Function in Pregnant Women with and without Asthma

BACKGROUND

Spirometry is commonly used to assess and monitor lung function. It may also be a useful tool to monitor maternal health during pregnancy. However, large studies examining lung function across gestation are limited. Also, whether spirometry values follow the same pattern during pregnancy in women with and without asthma is unknown.

OBJECTIVE

To investigate the effect of advancing gestation, and its interaction with asthma, on lung function in a large well-defined cohort of pregnant women.

METHODS

Data were obtained from prospective cohorts involving women with (n = 770) and without (n = 259) asthma (2004-2017), recruited between 12 and 22 weeks' gestation. Lung function (forced vital capacity [FVC], FEV₁, FEV₁:FVC%) was assessed periodically during pregnancy using spirometry. Multilevel mixed-effect regression models were used to assess changes in lung function over gestation.

RESULTS

Asthma had a significant effect on baseline lung function (FEV₁%, -9%; FVC%, -3%; FEV₁:FVC%, -4%). FVC% decreased with advancing gestation (-0.07%/wk; 95% CI, -0.10 to -0.04]), as did FEV₁%, but only among those without asthma (women without asthma: -0.14%/wk, 95% CI, -0.22 to -0.06%; compared with women with asthma: 0.02%/wk, 95% CI, -0.01 to 0.06). FEV₁:FVC% remained relatively stable for women without asthma (0.03%/wk; 95% CI, -0.08 to 0.02), but increased for women with asthma (0.06%/wk; 95% CI, 0.04 to 0.16).

CONCLUSIONS

Data suggest that advancing gestation negatively affects FVC% and FEV₁%. This is consistent with extrapulmonary restriction from advancing pregnancy. Yet, the presence of asthma altered the trajectories of FEV₁% and FEV₁:FVC%. Optimal asthma management during pregnancy might have opposed the negative effects of gestation on lung function.

Prescribing for pregnancy: asthma

Topics for DTB review articles are selected by DTB's editorial board to provide concise overviews of medicines and other treatments to help patients get the best care. Articles include a summary of key points and a brief overview for patients. Articles may also have a series of multiple choice CME questions.

Serum 25 Hydroxyvitamin D Levels During Pregnancy in Women with Asthma: Associations with Maternal Characteristics and Adverse Maternal and Neonatal Outcomes

Low 25-hydroxyvitamin D (25(OH)D) levels are common in pregnancy and associated with adverse maternal/neonatal outcomes. In pregnant women with asthma, this study examined the association of lifestyle- and asthma-related factors on 25(OH)D levels and maternal/neonatal outcomes by vitamin D status. Serum 25(OH)D was measured at 16 and 35 weeks gestation in women with asthma (n = 103). Body mass index (BMI), gestational weight gain (GWG), smoking status, inhaled corticosteroid (ICS) use, asthma control, airway inflammation, and exacerbations, and maternal/neonatal outcomes were collected. Baseline and change (Δ) in 25(OH)D were modelled separately using backward stepwise regression, adjusted for season and ethnicity. Maternal/neonatal outcomes were compared between low (25(OH)D < 75 nmol/L at both time points) and high (≥75 nmol/L at one or both time points) vitamin D status. Fifty-six percent of women had low vitamin D status. Obesity was significantly associated with lower baseline 25(OH)D (Adj-R² = 0.126, p = 0.008); ICS and airway inflammation were not. Excess GWG and season of baseline sample collection were significantly associated with Δ25(OH)D (Adj-R² = 0.405, p < 0.0001); asthma-related variables were excluded (p > 0.2). Preeclampsia was more common in the low (8.6%) vs. high (0%) vitamin D group (p < 0.05). Obesity and excess GWG may be associated with gestational 25(OH)D levels, highlighting the importance of antenatal weight management.

INFECTIONS IN PREGNANCY WITH COVID-19 AND OTHER RESPIRATORY RNA VIRUS DISEASES ARE RARELY, IF EVER, TRANSMITTED TO THE FETUS: EXPERIENCES WITH CORONAVIRUSES, HPIV, hMPV RSV, AND INFLUENZA

SARS-CoV-2, the agent of COVID-19, is similar to two other coronaviruses, SARS-CoV and MERS-CoV, in causing life-threatening maternal respiratory infections and systemic complications. Because of global concern for potential intrauterine transmission of SARS-CoV-2 from pregnant women to their infants, this report analyzes the effects on pregnancy of infections caused by SARS-CoV-2 and other respiratory RNA viruses, and examines the frequency of maternal-fetal transmission with SARS-CoV-2, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), influenza, respiratory syncytial virus (RSV), parainfluenza (HPIV) and metapneumovirus (hMPV). There have been no confirmed cases of intrauterine transmission reported with COVID-19 or any other coronavirus infections. Influenza virus, despite causing approximately one billion annual infections globally, has only a few cases of confirmed or suspected intrauterine fetal infections reported. RSV is in an unusual cause of illness among pregnant women, and with the exception of one premature infant with congenital pneumonia, no other cases of maternal-fetal infection are described. Parainfluenza virus and human metapneumovirus can produce symptomatic maternal infections but do not cause intrauterine fetal infection. In summary, it appears that the absence thus far of maternal-fetal transmission of the SARS-CoV-2 virus during the COVID-19 pandemic is similar to other coronaviruses, and is also consistent with the extreme rarity of suggested or confirmed cases of intrauterine transmission of other respiratory RNA viruses. This observation has important consequences for pregnant women as it appears that if intrauterine transmission of SARSCoV-2 does eventually occur, it will be a rare event. Potential mechanisms of fetal protection from maternal viral infections are also discussed.

Asthma in Pregnancy: Pathophysiology, Diagnosis, Whole-Course Management, and Medication Safety

Asthma in pregnancy is a health issue of great concern. Physiological changes and drug compliance during pregnancy can affect asthma control in varying degrees, and the control level of asthma and the side effects of asthma medications are closely related to the adverse perinatal outcomes of mother and fetus. This article provides an update on the available literature regarding the alleviating or aggravating mechanism of asthma in pregnancy, diagnosis, disease assessment, and systematic management, to provide a new guidance for physician, obstetric joint doctor, and health care practitioner.

ERS/TSANZ Task Force Statement on the management of reproduction and pregnancy in women with airways diseases

This European Respiratory Society/Thoracic Society of Australia and New Zealand statement outlines a review of the literature and expert opinion concerning the management of reproduction and pregnancy in women with airways diseases: asthma, cystic fibrosis (CF) and non-CF bronchiectasis. Many women with these diseases are now living into reproductive age, with some developing moderate-to-severe impairment of lung function in early adulthood. The statement covers aspects of fertility, management during pregnancy, effects of drugs, issues during delivery and the post-partum period, and patients' views about family planning, pregnancy and parenthood. The statement summarises current knowledge and proposes topics for future research, but does not make specific clinical recommendations.

Nasal epithelial cells to assess in vitro immune responses to respiratory virus infection in pregnant women with asthma

Respiratory virus-induced asthma exacerbations occur frequently during pregnancy and are associated with adverse outcomes for mother and child. Primary nasal epithelial cells (pNECs) provide a useful method to study immune responses in pregnancy. pNECs were obtained by nasal brushings from pregnant and non-pregnant women with and without asthma. pNECS were infected in vitro with major group Rhinovirus 43 (RV43) and seasonal influenza (H3N2). Following infection, pNECs showed measurable quantities of interferon (IFN)-λ, IL-1β, IL-8, IP-10 and MIP1-α. pNECs provide a safe and effective method for studying respiratory epithelial cell responses during pregnancy.

Asymptomatic Summertime Shedding of Respiratory Viruses

To determine rates of both symptomatic and asymptomatic infection among ambulatory adults, we collected nasopharyngeal swab specimens, demographic characteristics, and survey information from 1477 adult visitors to a New York City tourist attraction during April–July 2016. Multiplex polymerase chain reaction analysis was used to identify specimens positive for common respiratory viruses. A total of 7.2% of samples tested positive for respiratory viruses; among positive samples, 71.0% contained rhinovirus, and 21.5% contained coronavirus. Influenza virus, respiratory syncytial virus, and parainfluenza virus were also detected. Depending on symptomatologic definition, 57.7%–93.3% of positive samples were asymptomatic. These findings indicate that significant levels of asymptomatic respiratory viral shedding exist during summer among the ambulatory adult population.

Algorithm for the management of asthma in pregnant women: a protocol to optimize processes in healthcare

INTRODUCTION

Asthma is the most common chronic disease in pregnant women. Its evolution during pregnancy could improve, stay the same or worsen, especially in cases where there is a loss of clinical control. This can lead to maternal and fetal hypoxia with serious adverse perinatal outcomes. Areas covered: This article reviews physiological modifications in pregnancy, effects of pregnancy on asthma, and possible consequences on fetus development. Furthermore, it reviews evidence on assessment and both pharmacological and non-pharmacological management of asthma in pregnant and breastfeeding women as well as in acute exacerbations. Electronic databases, such as PUBMED, were searched for terms pregnan* or perinat* or obstet* and breastfeeding or asthma or wheeze, as well as a book published by the present authors. Expert commentary: A patient-centered multidisciplinary approach, where the respiratory specialists have a key role in assessing and achieving control, as well as the education interventions for self-monitoring and adherence are at least as important as adequate pharmacological treatment.

Asthma Outcomes and Management During Pregnancy

Asthma during pregnancy poses a common, increasingly prevalent threat to the health of women and their children. The present article reviews recent insights gained from the epidemiology of asthma during pregnancy, demonstrating the many short- and long-term risks to mother and fetus incurred by poorly controlled maternal asthma. We further discuss emerging evidence that active management of asthma during pregnancy can positively influence and perhaps completely mitigate these poor outcomes. Recent high-quality trials examining best methods for asthma treatment are reviewed and synthesized to offer an evidence-based pathway for comprehensive treatment of asthma in the outpatient setting. Safe and effective medications, as well as nonpharmacologic interventions, for asthma during pregnancy are discussed, and treatment options for related conditions of pregnancy, including depression, rhinitis, and gastroesophageal reflux, are presented. Throughout, we emphasize that an effective treatment strategy relies on a detailed patient evaluation, patient education, objective measurement of asthma control, and frequent and supportive follow-up. The cardiovascular and respiratory physiology of pregnancy is reviewed, as well as its implications for the management of patients with asthma, including patients requiring intubation and mechanical ventilation. For the situation when outpatient asthma management has failed, an approach to the critically ill pregnant patient with status asthmaticus is detailed. Multidisciplinary teams that include pulmonary specialists, obstetricians, primary care providers, nurses, pharmacists, and asthma educators improve the care of pregnant women with asthma.

Health symptoms in relation to temperature, humidity, and self-reported perceptions of climate in New York City residential environments

Little monitoring has been conducted of temperature and humidity inside homes despite the fact that these conditions may be relevant to health outcomes. Previous studies have observed associations between self-reported perceptions of the indoor environment and health. Here, we investigate associations between measured temperature and humidity, perceptions of indoor environmental conditions, and health symptoms in a sample of New York City apartments. We measured temperature and humidity in 40 New York City apartments during summer and winter seasons and collected survey data from the households' residents. Health outcomes of interest were (1) sleep quality, (2) symptoms of heat illness (summer season), and (3) symptoms of respiratory viral infection (winter season). Using mixed-effects logistic regression models, we investigated associations between the perceptions, symptoms, and measured conditions in each season. Perceptions of indoor temperature were significantly associated with measured temperature in both the summer and the winter, with a stronger association in the summer season. Sleep quality was inversely related to measured and perceived indoor temperature in the summer season only. Heat illness symptoms were associated with perceived, but not measured, temperature in the summer season. We did not find an association between any measured or perceived condition and cases of respiratory infection in the winter season. Although limited in size, the results of this study reveal that indoor temperature may impact sleep quality, and that thermal perceptions of the indoor environment may indicate vulnerability to heat illness. These are both important avenues for further investigation.

Influence of Maternal Body Mass Index and Macrophage Activation on Asthma Exacerbations in Pregnancy

BACKGROUND

Obesity is a risk factor for exacerbations of asthma, but the mechanisms of this effect in pregnancy are unknown.

OBJECTIVE

This study determined the influence of maternal body mass index, gestational weight gain, eosinophilic inflammation, and systemic macrophage activation on the risk of exacerbations during pregnancy.

METHODS

Women with asthma (n = 164) participated in the study. Body mass index recorded at baseline (17 weeks gestation) was categorized as healthy weight (18.5-24.9 kg/m²), overweight (25-29.9 kg/m²), or obese (>30 kg/m²). Exacerbations requiring medical intervention were recorded prospectively. Asthma control, medication use, and fractional exhaled nitric oxide were assessed monthly; additional visits occurred during exacerbations. Peripheral blood was collected at baseline for the measurement of eosinophils, soluble CD-163, C-reactive protein, and IL-6.

RESULTS

Exacerbations occurred in a higher proportion of overweight (51.1%) and obese (48.4%) women compared with healthy weight women (25%; P = .026). Excess weight gain during pregnancy was not associated with exacerbation risk. Macrophage activation (elevated serum soluble CD-163) was associated with exacerbations requiring oral corticosteroids (P = .043), whereas high peripheral blood eosinophils or fractional exhaled nitric oxide were not associated with exacerbation or oral corticosteroid use.

CONCLUSIONS

Being overweight or obese confers a greater risk of asthma exacerbation during pregnancy, and may be due to systemic macrophage activation.

Maternal complications and the management of asthma in pregnancy

Pregnancy is a unique state requiring alterations in maternal physiology to accommodate the growing fetus. Whilst the maternal immune system is normally well adept at performing this task, the presence of immune disorders, such as asthma, often lead to pregnancy-related complications affecting both mother and baby. Australia has a high prevalence of asthma; with approximately 12% of pregnant women reported to have current asthma. Poor control of asthma is of far greater risk than the use of asthma medications. Being able to identify complications associated with asthma during pregnancy is of great importance in providing appropriate asthma management and medical care to these pregnant women, which may have lifelong consequences for their offspring.

Evidence that asthma is a developmental origin disease influenced by maternal diet and bacterial metabolites

Asthma is prevalent in Western countries, and recent explanations have evoked the actions of the gut microbiota. Here we show that feeding mice a high-fibre diet yields a distinctive gut microbiota, which increases the levels of the short-chain fatty acid, acetate. High-fibre or acetate-feeding led to marked suppression of allergic airways disease (AAD, a model for human asthma), by enhancing T-regulatory cell numbers and function. Acetate increases acetylation at the Foxp3 promoter, likely through HDAC9 inhibition. Epigenetic effects of fibre/acetate in adult mice led us to examine the influence of maternal intake of fibre/acetate. High-fibre/acetate feeding of pregnant mice imparts on their adult offspring an inability to develop robust AAD. High fibre/acetate suppresses expression of certain genes in the mouse fetal lung linked to both human asthma and mouse AAD. Thus, diet acting on the gut microbiota profoundly influences airway responses, and may represent an approach to prevent asthma, including during pregnancy.

Outdoor temperature changes and emergency department visits for asthma in Seoul, Korea: A time-series study

BACKGROUND

Extreme temperatures and temperature changes are known indicators of climate change, and large temperature variations for several consecutive days may affect human health such as exacerbating respiratory symptoms. The objective of this study was to determine the association between outdoor temperature change and asthma-related emergency department visits. In particular, this study examined seasonality and identified susceptible populations, such as the elderly.

METHODS

The health data for asthma-related emergency department visits were collected from July 1, 2007, to December 31, 2010 in Seoul, Korea, through the National Emergency Department Information System of the National Emergency Medical Center and we defined temperature change as the absolute difference of mean temperature between the current day and the previous day. We applied generalized linear models with an allowance of over-dispersion for quantifying the estimated effects of temperature change on asthma-related emergency department visits, adjusting for meteorological conditions, air pollution, and time trend.

RESULTS

In general, temperature change was adversely associated with asthma-related emergency department visits, with a 1-unit increase of temperature change associated with a 3.5% (95% CI 0.7, 6.4%) increase in emergency department visits. In addition, seasonal variation after adjusting for mean temperature and diurnal temperature range had an adverse effect in spring, summer, and fall and a protective effect in winter. Patients aged ≥65 years experienced the most prominent effect during the fall, with a 17.9% (95% CI 4.1, 33.6%) increase in emergency department visits per 1-unit increase of temperature change, whereas the other seasons showed no statistically significant association.

CONCLUSIONS

Along with diurnal temperature range, temperature change may be an alternative indicator of climate change. Temperature change variables are well-known and easy to communicate with the public relative to the health effects of outdoor temperature fluctuations.

Respiratory viral infections in pregnant women with asthma are associated with wheezing in the first 12 months of life

BACKGROUND

There are few studies investigating the relationship between respiratory viral infection in pregnancy and asthma in the offspring, and none among mothers with asthma. Infants of mothers with asthma are more likely to wheeze and have a higher risk of developing asthma than infants of non-asthmatic mothers.

METHODS

A prospective cohort study of viral infection in pregnancy was conducted between 2007 and 2009, and a subgroup of infants of mothers with asthma was followed up at 6 and 12 months of age. During common colds, nasal and throat swabs were collected from mothers and respiratory viruses detected by polymerase chain reaction. Respiratory health of infants was assessed by parent-completed questionnaire.

RESULTS

Twelve-month-old infants whose mothers had confirmed viral infections in pregnancy (n = 26) reported more frequent wheeze (40% had 4-12 wheeze attacks compared with 0%), sleep disturbed by wheeze (1 night per week or more in 60% vs. 11%), beta agonist treatment for wheeze (27% vs. 0%), prolonged colds (2 wk or longer 31% vs. 0%), more eczema (40% vs. 6.3%), and parent-perceived asthma (32% vs. 0%), compared with infants whose mothers had common colds without laboratory-confirmed viral infection (n = 16).

CONCLUSIONS

This study demonstrates a relationship between maternal respiratory viral infection in pregnancy and wheezing illness in infants of mothers with asthma. Viral infections are the most common cause of asthma exacerbations in pregnancy, and infants of asthmatic mothers are at increased risk of asthma themselves. Further research is needed to elucidate the mechanisms involved.