Factors Associated with Asthma Exacerbations During Pregnancy

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.

Managing Asthma During Pregnancy and the Postpartum Period

Asthma is one of the most common chronic diseases in pregnancy and is associated with adverse perinatal outcomes. Asthma symptoms worsen in approximately 40% of women, and exacerbations requiring medical intervention occur in at least 20% of women. Factors associated with exacerbation and worsening asthma include multiparity, obesity, Black race, exacerbations before pregnancy, and poor asthma control. Exacerbations are associated with further increased risks for poor perinatal outcomes, including low birth weight, preterm birth, and small for gestational age (SGA) status, as well as an increase in the development of asthma in early childhood. Common medications used for asthma, including short-acting β-agonists and inhaled corticosteroids, are considered safe to use in pregnancy. Whereas guidelines generally suggest traditional step therapy for managing asthma in pregnancy, there are alternative models of care and management approaches that may be effective in pregnancy, but require more research. These include single-inhaler maintenance and reliever therapy, treatment adjustment with FeNO, treatable traits personalized medicine approaches, and telemedicine. Little is known about changes to asthma in the postpartum period. However, low adherence to medication and the potential effects of postpartum depression on asthma exacerbation risk warrant further research.

Asthma in Pregnancy

Asthma is a common chronic respiratory condition that affects approximately 10% of adult women in the United States. Pregnancy can present unique challenges for women with asthma, as changes in the body can alter the severity and management of asthma-related respiratory symptoms. In this article, we review the current understanding of asthma during pregnancy, including the direct effects of the disease state on the pregnant woman and fetus, risk factors for poor control of disease, as well as current treatment recommendations.

Status Asthmaticus Gravidus: Emergency and Critical Care Management of Acute Severe Asthma During Pregnancy

One-third of women with asthma have deterioration of their asthma during pregnancy, and one-fourth of pregnant women with asthma will experience severe exacerbations necessitating emergency department (ED) visits or hospitalizations. Early recognition of acute severe asthma, including life-threatening status asthmaticus, and aggressive medical interventions with β2-agonists, anticholinergic agents, and systemic corticosteroids are necessary to treat maternal airway bronchoconstriction, support maternal and fetal oxygenation, and avoid adverse fetal outcomes. This review describes management of acute severe asthma in pregnancy, including status asthmaticus, in the ED and intensive care unit.

Maternal asthma in Australian indigenous women and perinatal outcomes: A whole population-linked study

OBJECTIVE

To assess the association between maternal asthma and adverse perinatal outcomes in an Australian Indigenous population.

METHODS

This prospective cohort study included all Indigenous mother and baby dyads for births from 2001 to 2013 in Western Australia (n = 25 484). Data were linked from Western Australia Births, Deaths, Midwives, Hospital, and Emergency Department collections. Maternal asthma was defined as a self-reported diagnosis at an antenatal visit or hospitalization or emergency visit for asthma during pregnancy or less than 3 years before pregnancy. Associations with birth, labor, and pregnancy outcomes were assessed using generalized estimating equations. Asthma exacerbation during pregnancy and stratification by remoteness was also assessed.

RESULTS

Maternal asthma was associated with placental abruption (adjusted odds ratio [aOR], 1.59 [95% confidence interval (CI), 1.07-2.35]), threatened preterm labor (aOR, 1.58 [95% CI, 1.39-1.79]), and emergency cesarean sections (aOR, 1.27 [95% CI, 1.13-1.44]). These risks increased further with an asthma exacerbation during pregnancy or if the mother was from a remote area. No associations were found for low birth weight, preterm birth, small for gestational age, or perinatal mortality.

CONCLUSION

Maternal asthma in Indigenous women is associated with an increased risk of emergency cesarean sections, placental abruption, and threatened preterm labor. These risks may be mitigated by improved management of asthma exacerbations during pregnancy.

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.

The obstetric aspects of maternal asthma

Asthma is the commonest chronic medical condition encountered in pregnancy. Poor asthma control and exacerbations are frequently encountered due to treatment non-adherence, pregnancy-related aggravating factors such as increased susceptibility to viral infections, and comorbidities that are commonly associated. Asthma-related inflammatory reactions and placental effects, the effect of medications, and respiratory symptoms and hypoxia are probably to interact to result in an increased adverse obstetric outcomes including miscarriage, foetal congenital anomalies, pregnancy hypertensive disorders, gestational diabetes, preterm labour and birth, antepartum haemorrhage, low birthweight and foetal growth restriction (FGR), caesarean delivery, postpartum haemorrhage (PPH), maternal intensive care admission, and even mortality, while the offspring also has increased long-term morbidity. Interdisciplinary management with frequent assessment by symptoms, spirometry, and biomarkers, together with removal of risk factors such as smoking and appropriate instigation of treatment including short courses of systemic corticosteroid, could ensure optimal and tailored treatment to control symptoms, prevent exacerbations, and ultimately enhancing maternal and perinatal outcomes.

Risk factors for asthma exacerbations during pregnancy: a systematic review and meta-analysis

BACKGROUND

Conflicting literature exists regarding the risk factors for exacerbations among pregnant women with asthma. This systematic review and meta-analysis aimed to determine risk factors for asthma exacerbations during pregnancy.

METHODS

Electronic databases were searched for the following terms: (asthma or wheeze) and (pregnan* or perinat* or obstet*) and (exacerb* or flare up or morbidit* or attack*).All studies published between 2000 and 24 August 2021 were considered for inclusion if they reported at least one potential risk factor of asthma exacerbations in pregnant women with asthma. Of the 3337 references considered, 35 publications involving 429 583 pregnant women with asthma were included. Meta-analyses were conducted to determine mean difference in risk factor between exacerbation groups, or the relative risks of exacerbation with certain risk factors. Good study quality was found through the Newcastle-Ottawa Scale (median score 8, interquartile range 7-9).

RESULTS

Increased maternal age (mean difference 0.62, 95% CI 0.11-1.13), obesity (relative risk 1.25, 95% CI 1.15-1.37), smoking (relative risk 1.35, 95% CI 1.04-1.75), black ethnicity (relative risk 1.62, 95% CI 1.52-1.73), multiparity (relative risk 1.31, 95% CI 1.01-1.68), depression/anxiety (relative risk 1.42, 95% CI 1.27-1.59), moderate-severe asthma (relative risk 3.44, 95% CI 2.03-5.83, versus mild) and severe asthma (relative risk 2.70, 95% CI 1.85-3.95, versus mild-moderate) were associated with an increased risk of asthma exacerbations during pregnancy.

CONCLUSIONS

Future interventions aimed at reducing exacerbations in pregnancy could address the modifiable factors, such as smoking and depression/anxiety, and introduce more regular monitoring for those with nonmodifiable risk factors such as obesity and more severe asthma.

Challenges in the successful management of asthma during conception, pregnancy and delivery

Asthma and infertility are the most common disorders among women of reproductive age. Time to pregnancy is prolonged in women with asthma, and importantly, age seems to be a more important risk factor regarding fertility in women with asthma compared to women without asthma. Some data have shown a higher frequency of miscarriages in women with asthma, although the data are conflicting on this issue as studies have observed no association between asthma and pregnancy loss. Furthermore, studies have shown no negative effect of asthma on the total number of offspring. Pregnancy may, thus, have a significant impact on women with asthma, as well as on their offspring.

The age of the women has an important impact on ability to conceive, but also for the pregnancy itself, with higher risk of uncontrolled asthma as well as asthma exacerbations with increasing age. Well-controlled asthma decreases the risk of maternal and fetal complications, while poorly controlled and undertreated asthma is associated with a range of risks for both mother and fetus. Asthma treatment should follow the general guidelines for asthma therapy, irrespective of pregnancy status, including treatment with inhaled corticosteroids, β2-agonists and muscarinic antagonists. Targeted treatment with biologics for severe asthma seems to be without important adverse effects. The use of systemic corticosteroids may be associated with adverse events during the first trimester; however, an exacerbation with the associated risk of hypoxaemia is worse for the fetus. Best possible asthma control may be achieved using repeated measurements of fractional exhaled nitric oxide (FENO), as the use of FENO compared with symptoms registration only has been shown to reduce exacerbation rate.

In conclusion, women with asthma should be encouraged to conceive at an early age, might experience miscarriages, but the number of offspring are the same as in women without asthma. Well treated asthma is important for the well-being of both the mother and the unborn fetus.

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.

Sex Disparities in Asthma Development and Clinical Outcomes: Implications for Treatment Strategies

A gender-related disparity exists in asthma morbidity and mortality, which shifts at around puberty from a male predominance to a female predominance. This is clinically reflected in the fact that asthma that occurs in childhood (childhood-onset asthma) mainly affects boys, and that asthma that occurs in adulthood (adult-onset asthma) mainly affects women. Adult-onset asthma is often non-atopic, more severe, and associated with a poorer prognosis, thus posing a marked burden to women’s health and healthcare system. Many factors have been indicated to explain this gender-related disparity, including sociocultural and environmental factors as well as biological sex differences (genetic, pulmonary and immunological factors). It has long been suggested that sex hormones may be implicated in at least these biological sex differences. Overall, the evidence remains equivocal for the role of most sex hormones in asthma pathogenesis and clinical outcomes. Well-designed randomized clinical trials are required assessing the potential preventive or therapeutic effects of hormonal contraceptives on asthma in women, thereby helping to advance the evidence to inform future practice guidelines. The mechanisms underlying the role of sex hormones in asthma are complex, and our understanding is not yet complete. Additional mechanistic studies elucidating sex hormone signaling pathways and their interactions involved in the pathogenesis and clinical manifestations of asthma will help to identify potential sex hormone-driven asthma endotypes and novel therapeutic targets, providing the basis for a more personalized asthma management strategy.