Pregnancy outcome in asthmatic patients from high altitudes

Adverse neonatal outcomes in pregnant women with asthma: An updated systematic review and meta-analysis

BACKGROUND

A systematic review and meta-analysis from 2013 reported increased risks of congenital malformations, neonatal death and neonatal hospitalization amongst infants born to women with asthma compared to infants born to mothers without asthma.

OBJECTIVE

Our objective was to update the evidence on the associations between maternal asthma and adverse neonatal outcomes.

SEARCH STRATEGY

We performed an English-language MEDLINE, Embase, CINAHL, and COCHRANE search with the terms (asthma or wheeze) and (pregnan* or perinat* or obstet*).

SELECTION CRITERIA

Studies published from March 2012 until September 2023 reporting at least one outcome of interest (congenital malformations, stillbirth, neonatal death, perinatal mortality, neonatal hospitalization, transient tachypnea of the newborn, respiratory distress syndrome and neonatal sepsis) in a population of women with and without asthma.

DATA COLLECTION AND ANALYSIS

The study was reported following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) and the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Quality of individual studies was assessed by two reviewers independently using the Newcastle-Ottawa Scale. Random effects models (≥3 studies) or fixed effect models (≤2 studies) were used with restricted maximum likelihood to calculate relative risk (RR) from prevalence data and the inverse generic variance method where adjusted odds ratios (aORs) from individual studies were combined.

MAIN RESULTS

A total of 18 new studies were included, along with the 22 studies from the 2013 review. Previously observed increased risks remained for perinatal mortality (relative risk [RR] 1.14, 95% confidence interval [CI]: 1.05, 1.23 n = 16 studies; aOR 1.07, 95% CI: 0.98-1.17 n = 6), congenital malformations (RR 1.36, 95% CI: 1.32-1.40 n = 17; aOR 1.42, 95% CI: 1.38-1.47 n = 6), and neonatal hospitalization (RR 1.27, 95% CI: 1.25-1.30 n = 12; aOR 1.1, 95% CI: 1.07-1.16 n = 3) amongst infants born to mothers with asthma, while the risk for neonatal death was no longer significant (RR 1.33, 95% CI: 0.95-1.84 n = 8). Previously reported non-significant risks for major congenital malformations (RR1.18, 95% CI: 1.15-1.21; aOR 1.20, 95% CI: 1.15-1.26 n = 3) and respiratory distress syndrome (RR 1.25, 95% CI: 1.17-1.34 n = 4; aOR 1.09, 95% CI: 1.01-1.18 n = 2) reached statistical significance.

CONCLUSIONS

Healthcare professionals should remain aware of the increased risks to neonates being born to mothers with asthma.

Effect of fractional exhaled nitric oxide (FENO)-based asthma management during pregnancy versus usual care on infant development, temperament, sensory function and autism signs

Asthma during pregnancy is associated with a range of adverse perinatal outcomes. It is also linked to increased rates of neurodevelopmental conditions in the offspring. We aimed to assess whether fractional exhaled nitric oxide (FENO)-based asthma management during pregnancy improves child developmental and behavioural outcomes compared to usual care. The Breathing for Life Trial was a randomised controlled trial that compared FENO-based asthma management during pregnancy to usual care. Participants were invited to the developmental follow-up, the Breathing for Life Trial - Infant Development study, which followed up infants at 6 weeks, 6 months and 12 months. The primary outcomes were measured in infants at 12 months using the Bayley-III: Cognitive, Language and Motor composite scores. Secondary outcomes included Bayley-III social-emotional and adaptive behaviour scores, autism likelihood and sensory and temperament outcomes. The exposure of interest was the randomised intervention group. Two hundred and twenty-two infants and their 217 participating mothers were recruited to the follow-up; 107 mothers were in the intervention group and 113 were in the control group. There was no evidence of an intervention effect for the primary outcomes: Bayley-III cognitive (mean = 108.9 control, 108.5 intervention, p = 0.93), language (mean = 95.9 control, 95.6 intervention, p = 0.87) and motor composite scores (mean = 97.2 control, 97.9 intervention, p = 0.25). Mean scores for secondary outcomes were also similar among infants born to control and FENO group mothers, with few results reaching p < 0.05.

CONCLUSION

 In this sample, FENO-guided asthma treatment during pregnancy did not improve infant developmental outcomes in the first year of life.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: ACTRN12613000202763.

WHAT IS KNOWN

• Maternal asthma during pregnancy has been associated with increased rates of neurodevelopmental conditions in offspring, including intellectual disability and autism.

WHAT IS NEW

• This is the first study to examine how managing asthma during pregnancy via a FENO-guided algorithm or usual care affects infant developmental and behavioural outcomes. While the results of the study showed no impact of the intervention, and therefore do not support the integration of FENO-based management of asthma in antenatal settings for optimal infant development, they do send a positive message about the implications of active asthma management during pregnancy on infant developmental outcomes.

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.

Asthma Is Associated With Pregnancy Loss and Recurrent Pregnancy Loss: A Nationwide Cohort Study

BACKGROUND

Women with asthma appear to have an increased risk of pregnancy loss (PL). The impact of asthma on recurrent pregnancy loss (RPL), defined as 3 consecutive losses, is, however, unknown.

OBJECTIVE

The aim of this study was to investigate whether having asthma before or during the fertile age is associated with PL and RPL.

METHODS

Based on Danish national health registers, we identified all women aged 6 to 45 years with at least 2 filled prescriptions of an antiasthma drug during the period 1977 to 2019. Women with asthma were compared with women without asthma. Pregnancy outcomes were retrieved for both groups from national health registers. Logistic regression with adjustment for the year of birth and educational level provided odds ratios (ORs) for the number of PLs. Subgroup analyses were conducted for early-onset (age 6-15 years), adult-onset (age 16-39 years), and late-onset (age 40-45 years) asthma. Lastly, we compared uncontrolled asthma (defined as ≥ 400 doses of a short-acting beta-2 agonist in a year) to controlled asthma (defined as < 400 doses of a short-acting beta-2 agonist in a year).

RESULTS

In a population of 1,309,786 women, we identified 128,553 women with asthma and 1,297,233 women without asthma. Compared with nonasthmatic women, women with asthma had ORs for 1, 2, and 3 or more PLs of 1.05 (95% CI 1.03-1.07), 1.09 (95% CI 1.05-1.13), and 1.18 (95% CI1.11-1.24), respectively, and for RPL of 1.19 (95% CI 1.12-1.27). In women with early-onset asthma, the OR of 3 or more PLs was 1.47 (95% CI 1.24-1.72). For women classified as having uncontrolled asthma compared with controlled asthma, we found a significant OR of 1.60 (95% CI 1.16-2.16) for 3 or more PLs.

CONCLUSIONS

We found a significant positive association between asthma and number of PLs and RPLs. Early-onset asthma and uncontrolled asthma were more strongly associated with PL than adult-onset and late-onset asthma and controlled 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.

Maternal asthma and the risk of hypertensive disorders of pregnancy: a systematic review and meta-analysis of cohort studies

Objective: The aim of this study was to demonstrate the association between maternal asthma and the risk of hypertensive disorders of pregnancy.Methods: A systematic search of seven databases was conducted. A meta-analysis was performed to calculate risk ratios and 95% CI using random-effects models.Results: Asthma was associated with an increased risk of pregnancy-induced hypertension (RR 1.45, 95%CI 1.29-1.63), transient hypertension of pregnancy (RR 2.00, 95%CI 1.52-2.63), preeclampsia or eclampsia (RR 1.28, 95%CI 1.25-1.32), preeclampsia (RR 1.43, 95%CI 1.31-1.57) and eclampsia (RR 1.56, 95%CI 1.13-2.15).Conclusion: The meta-analysis illustrated that asthma was significantly increased risk of hypertension during pregnancy.

Meta-Analysis Finds Use of Inhaled Corticosteroids During Pregnancy Safe: A Systematic Meta-Analysis Review

Inhaled corticosteroids (ICs) are the drug of choice for asthmatic women during pregnancy, but the results on the effects of these medications on obstetrical and perinatal outcomes are not conclusive. Meta-analysis is the statistical analysis of a collection of analysis results from individual studies for the purpose of integrating the findings. Meta-analysis techniques are necessary because only summary statistics are available in the literature. In order to determine the risk of exposure to ICs, we pooled data from all clinical studies that evaluated the pregnancy and perinatal outcomes in women exposed to this group of drugs during pregnancy by the meta-analytic technique.

PUBMED, OVID, EMBASE and SCOPUS databases were searched for studies that investigated birth outcome following exposure to ICs during pregnancy. Data were collected from 1997 to 2005 (up to 31 December). Types of outcome investigated were major malformations, pre-term delivery, low birth weight and pregnancy-induced hypertension. The criteria for inclusion of studies in this meta-analysis were exposure of women to any therapeutic dosage of any ICs (fluticasone, beclomethasone, budesonide, triamcinolone and flunisolide) during pregnancy.

The results showed that ICs do not increase the risk of major malformations, preterm delivery, low birth weight and pregnancy-induced hypertension. In conclusion, ICs do not increase the rates of any obstetrical outcomes investigated in the present study and interestingly improve the symptoms and are helpful in the management of asthma and thus can be used comfortably during pregnancy.

Exacerbations of asthma during pregnancy: Impact on pregnancy complications and outcome

Asthma is common among pregnant women, and the incidence of asthma exacerbations during pregnancy is high. This literature review provides an overview of the impact of exacerbations of asthma during pregnancy on pregnancy-related complications. The majority of published retrospective studies reveal that asthma exacerbations during pregnancy increase the risk of pre-eclampsia, gestational diabetes, placental abruption and placenta praevia. Furthermore, these women also have higher risk for breech presentation, haemorrhage, pulmonary embolism, caesarean delivery, maternal admission to the intensive care unit and longer postpartum hospital stay. Asthma has been associated with increased risk of intrauterine growth retardation, small-for-gestational age, low birth weight, infant hypoglycaemia and preterm birth, but more recent prospective studies have not revealed significant associations with regard to these outcomes. In conclusion, asthma exacerbations during pregnancy are associated with complications of pregnancy, labour and delivery. Prevention of exacerbations is essential to reduce the risk of complications and poor outcome.

The risk of maternal and placental complications in pregnant women with asthma: a systematic review and meta-analysis

OBJECTIVE

To investigate if maternal asthma is associated with an increased risk of maternal and placental complications in pregnancy.

METHODS

Electronic databases were searched for the following terms: (asthma or wheeze) and (pregnan* or perinat* or obstet*). Cohort studies published between January 1975 and March 2012 were considered for inclusion. Forty publications met the inclusion criteria, reporting at least one maternal or placental complication in pregnant women with and without asthma. Relative risk (RR) with 95% confidence intervals (CIs) was calculated.

RESULTS

Maternal asthma was associated with a significantly increased risk of cesarean section (RR = 1.31, 95%CI = [1.22-1.39]), gestational diabetes (RR = 1.39, 95%CI = [1.17-1.66]), hemorrhage (antepartum: RR = 1.25, 95%CI = [1.10-1.42]; postpartum: RR = 1.29, 95%CI = [1.18-1.41]), placenta previa (RR = 1.23, 95%CI = [1.07-1.40]), placental abruption (RR = 1.29, 95%CI = [1.14-1.47]) and premature rupture of membranes (RR = 1.21, 95%CI = 1.07-1.37). Moderate to severe asthma significantly increased the risk of cesarean section (RR = 1.19, 95%CI = [1.09-1.31]) and gestational diabetes (RR = 1.19, 95%CI = [1.06-1.33]) compared to mild asthma. Bronchodilator use was associated with a significantly lowered risk of gestational diabetes (RR = 0.64, 95%CI = [0.57-0.72]).

CONCLUSIONS

Pregnant women with asthma are at increased risk of maternal and placental complications, and women with moderate/severe asthma may be at particular risk. Further studies are required to elucidate whether adequate control of asthma during pregnancy reduces these risks.

The risk of congenital malformations, perinatal mortality and neonatal hospitalisation among pregnant women with asthma: a systematic review and meta-analysis

BACKGROUND

There is conflicting literature on the effect of maternal asthma on congenital malformations and neonatal outcomes.

OBJECTIVES

This review and meta-analysis sought to determine if maternal asthma is associated with an increased risk of adverse neonatal outcomes.

SEARCH STRATEGY

We searched electronic databases for: (asthma or wheeze) and (pregnan* or perinat* or obstet*).

SELECTION CRITERIA

Cohort studies published between 1975 and March 2012 reporting at least one perinatal outcome of interest (congenital malformations, neonatal complications, perinatal mortality).

DATA COLLECTION AND ANALYSIS

In all, 21 studies met inclusion criteria in pregnant women with and without asthma. Further analysis was conducted on 16 studies where asthmatic women were stratified by exacerbation history, corticosteroid use, bronchodilator use or asthma severity.

MAIN RESULTS

Maternal asthma was associated with a significantly increased risk of congenital malformations (relative risk [RR] 1.11, 95% confidence interval [95% CI] 1.02-1.21, I(2)  = 59.5%), cleft lip with or without cleft palate (RR 1.30, 95% CI 1.01-1.68, I(2)  = 65.6%), neonatal death (RR 1.49, 95% CI 1.11-2.00, I(2)  = 0%), and neonatal hospitalisation (RR 1.50, 95% CI 1.03-2.20, I(2)  = 64.5%). There was no significant effect of asthma on major malformations (RR 1.31, 95% CI 0.57-3.02, I(2)  = 70.9%) or stillbirth (RR 1.06, 95% CI 0.9-1.25, I(2)  = 35%). Exacerbations and use of bronchodilators and inhaled corticosteroids were not associated with congenital malformation risk.

AUTHORS' CONCLUSIONS

Despite limitations related to the observational nature of the primary studies, this review demonstrates a small increased risk of neonatal complications among pregnant women with asthma. Further investigations into mechanisms and potential preventive interventions to improve infant outcomes are required.

Relationship between maternal asthma, its severity and control and abortion

STUDY QUESTION

Are women with asthma, and more specifically those with severe or uncontrolled asthma, at higher risk of spontaneous and induced abortions?

SUMMARY ANSWER

Pregnant women with asthma, notably when uncontrolled, are at higher risk of spontaneous abortion.

WHAT IS KNOWN ALREADY

Only one study has examined the association between asthma and spontaneous and induced abortions and revealed a modest increase in the risk of spontaneous abortions, particularly in women with more severe asthma and those with previous exacerbations, and a marginal decrease in the risk of induced abortions.

STUDY DESIGN, SIZE, DURATION

A cohort of pregnancies from asthmatic (n = 15,107) and non-asthmatic (n = 34,331) women was reconstructed by linking three administrative databases from Quebec (Canada), between 1992 and 2002. The cohort included 7870 spontaneous abortions, 14,596 induced abortions and 26,972 live births.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Pregnant women with and without asthma were analyzed. Asthma was defined by at least one asthma diagnosis and one dispensed prescription for an asthma medication in the 2 years prior to or during pregnancy. Asthma severity and control were assessed using validated indexes in the year before the 20th week of pregnancy or the termination of the pregnancy. Logistic polytomous regression models were used to estimate the relationship between asthma and asthma severity and control on the risk of abortion, while adjusting for potential confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

The prevalence of spontaneous and induced abortions was 15.9 and 29.5%, respectively. Maternal asthma was associated with an increased risk of a spontaneous abortion [odds ratio (OR) = 1.41; 95% confidence interval (CI): 1.33-1.49] and a decreased risk of induced abortions (OR = 0.92; 0.88-0.97). No association was observed between asthma severity and abortion, while uncontrolled asthma increased the risk of a spontaneous abortion by 26% (95% CI: 14-41%) and the risk of induced abortions by 11% (95% CI: 1-21%).

LIMITATIONS, REASONS FOR CAUTION

It is possible that the study results were confounded by imbalances between groups in variables that are not recorded in the databases, but that are known to be associated with spontaneous abortions, such as alcohol consumption, obesity or maternal smoking. However, we performed sensitivity analyses which revealed that these factors are unlikely to explain the observed increased risk for a spontaneous abortion. It is also possible that women with asthma are more likely to have abortions recorded in the databases, because subjects with a chronic disease tend to visit a physician more often than those without asthma. Therefore, our odds estimates for these outcomes may be overestimated when asthmatic women were compared with non-asthmatic women. A further limitation of the study is that it would have been more appropriate to measure the severity and control of asthma only during the pregnancy.

WIDER IMPLICATIONS OF THE FINDINGS

Our cohort is less representative of women in the upper socio-economic level. This is not a threat to internal validity, but it could limit the external validity if the impact of asthma on the risk of abortion differed according to the socio-economic status of the mother. Despite the absence of supporting data, this possibility cannot be completely excluded.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the Canadian Institutes of Health Research and Genentech. L.B. received research grants from Astra-Zeneca, Pfizer, sanofi-aventis, Novartis and Merck for research projects and co-chairs the Astra-Zeneca Endowment Pharmaceutical Chair in Respiratory Health. F.Z.K and A.F. have no competing interests to declare.

Foreign body aspiration in pregnancy

A 24-year-old morbidly obese African American gravida 1, with a history of severe asthma complicated by multiple inpatient admissions, presents at 30 weeks gestation with a foreign body in her left main stem bronchus. After a failed bronchoscopy postpartum, the patient slipped into respiratory failure and was subsequently intubated, spending two weeks in the intensive care unit. After two more attempts of trying to retrieve the foreign object from her lung via bronchoscopy, she eventually contracted a postobstructive pneumonia and underwent a left lower lung lobectomy for curative treatment.

A meta-analysis of adverse perinatal outcomes in women with asthma

BACKGROUND

Asthma is a common condition during pregnancy and may be associated with adverse perinatal outcomes.

OBJECTIVE

This meta-analysis sought to establish if maternal asthma is associated with an increased risk of adverse perinatal outcomes, and to determine the size of these effects.

SEARCH STRATEGY

Electronic databases were searched for the following terms: (asthma or wheeze) and (pregnan* or perinat* or obstet*).

SELECTION CRITERIA

Cohort studies published between 1975 and March 2009 were considered for inclusion. Studies were included if they reported at least one perinatal outcome in pregnant women with and without asthma.

DATA COLLECTION AND ANALYSIS

A total of 103 articles were identified, and of these 40 publications involving 1,637,180 subjects were included. Meta-analysis was conducted with subgroup analyses by study design and active asthma management.

MAIN RESULTS

Maternal asthma was associated with an increased risk of low birthweight (RR 1.46, 95% CI 1.22-1.75), small for gestational age (RR 1.22, 95% CI 1.14-1.31), preterm delivery (RR 1.41, 95% CI 1.22-1.61) and pre-eclampsia (RR 1.54, 95% CI 1.32-1.81). The relative risk of preterm delivery and preterm labour were reduced to non-significant levels by active asthma management (RR 1.07, 95% CI 0.91-1.26 for preterm delivery; RR 0.96, 95% CI 0.73-1.26 for preterm labour).

AUTHOR'S CONCLUSIONS

Pregnant women with asthma are at increased risk of perinatal complications, including pre-eclampsia and outcomes that affect the baby's size and timing of birth. Active asthma management with a view to reducing the exacerbation rate may be clinically useful in reducing the risk of perinatal complications, particularly preterm delivery.

Asthma in pregnancy

Worldwide the prevalence of asthma among pregnant women is on the rise, and pregnancy leads to a worsening of asthma for many women. This article examines the changes in asthma that may occur during pregnancy, with particular reference to asthma exacerbations. Asthma affects not only the mother but the baby as well, with potential complications including low birth weight, preterm delivery, perinatal mortality, and preeclampsia. Barriers to effective asthma management and opportunities for optimized care and treatment are discussed, and a summary of the clinical guidelines for the management of asthma during pregnancy is presented.

Effect of maternal asthma on the risk of specific congenital malformations: A population-based cohort study

BACKGROUND

There is a lack of consensus in the literature about the effect of maternal asthma on the development of congenital malformations.

OBJECTIVE

To further examine the association between maternal asthma and the risk of congenital malformations.

METHODS

A cohort of 41,637 pregnancies from women with and without asthma who delivered between 1990 and 2002 was reconstructed by linking three Quebec (Canada) administrative databases. All cases of malformations were identified using either the medical services or the hospital databases. The main exposure was maternal asthma, defined by the presence of at least one asthma diagnosis and at least one prescription for an asthma medication at any time in the two years before or during pregnancy. Generalized Estimation Equation models were performed to estimate the adjusted odds ratio (OR) of congenital malformations as a function of maternal asthma.

RESULTS

The crude prevalences of any congenital malformation were 9.5% and 7.5% for women with and without asthma, respectively. Maternal asthma was significantly associated with an increased risk of any malformation (OR=1.30; 95% CI: 1.20-1.40) and three specific groups (at the 0.0028 level): nervous system (excluding spina bifida: OR=1.83; 1.37-2.83); respiratory system (OR=1.75; 1.21-2.53); and digestive system (OR=1.48; 1.19-1.85).

CONCLUSIONS

Maternal asthma increases the risk of specific groups of congenital malformations. The disease itself, through fetal oxygen impairment, is likely to play a role in this increased risk, but more research is needed to disentangle the relative effect of asthma and medications used to treat this disease.

Asthma and pregnancy: a review of two decades

The prevalence of asthma among pregnant women varies among studies from 4 to 8%, making it by far the most common respiratory disorder complicating pregnancy. Controversy exists among the numerous retrospective and prospective studies regarding pregnancy outcomes of asthmatic patients. Overall, the literature indicates that women with severe asthma are at an increased risk for preterm delivery, low birth weight, preeclampsia and Caesarean delivery, especially in the absence of inhaled corticosteroid therapy. Asthmatic women carrying a female fetus may particularly be at increased risk of these adverse outcomes. On the other hand, mild or moderate, well-controlled asthma is associated with favorable pregnancy and perinatal outcomes. Pregnancy also influences the course of asthma. Recently published data indicate that the real risk for an exacerbation during pregnancy may be underestimated. There is no question, however, that the risk of having an exacerbation correlates closely with the severity of asthma. The mechanisms responsible for these changes are not fully understood. Maternal hypoxia or inflammatory processes have been suggested and could explain reduced fetal growth through alterations in placental function. The goal of asthma therapy is to maintain adequate oxygenation of the fetus by prevention of exacerbations. Optimal management of asthma during pregnancy should include scheduled monitoring of objective lung function tests, avoiding triggers, patient education and tailored pharmacologic therapy. Inhaled corticosteroids are the treatment of choice for all levels of persistent asthma, yet other drug classes, such as beta(2)-agonists and theophylline, are effective and safe for use during pregnancy.

A literature review of air medical work hazards and pregnancy

An increased percentage of miscarriages among coworkers at one air medical transport company in 2008 prompted a literature review of selected hazards relevant to the profession of rotor wing air medical flight crew. Because of a lack of known research specific to this population, relevant studies from 1990 to 2008 were chosen to investigate pregnancy risks associated with exposure to vibration, jet fuel, noise, altitude, and fatigue in other occupations. Findings were summarized and recommendations made for future research.

[Asthma and pregnancy. Review of the current literature and management according to the GINA 2006-2007 guidelines]

INTRODUCTION

Many pregnant women are asthmatics and maternal asthma is a source of questions and complications concerning both the progress of the pregnancy itself and the impact on the foetus. In this situation good asthma control is essential as the disease can deteriorate with acute exacerbations, possibly precipitated by reduction or even withdrawal of treatment on account of fear of teratogenicity.

BACKGROUND

Even though asthma treatments are not totally harmless during pregnancy, their use has been validated by several studies and guidelines. To help clinicians, we undertake here a review of the complications induced by maternal asthma and its medications, and then suggest management guidelines according to the most recent publications.

CONCLUSIONS

The risks and benefits of asthma treatments should be explained in a real partnership between the patient and her general practitioner and specialists (obstetrician, chest physician or allergist). In order to reduce complications to both mother and child, perfect control of asthma is required and inhaled steroids remain the treatment of choice for partially or uncontrolled asthma in the pregnant woman.

Effect of maternal asthma and gestational asthma therapy on fetal growth

Asthma is a common chronic condition that might seriously complicate pregnancy and fetal development. This article provides a comprehensive review of the existing literature regarding the effect on fetal growth of maternal asthma and common asthma medications used during pregnancy, including short-and long-acting beta (2)-agonists, inhaled and oral corticosteroids, chromones, leukotriene receptor agonists, and theophylline. Evaluated outcomes of fetal growth include low birth weight, mean birth weight, small for gestational age, birth length and head circumference, and measures of asymmetrical growth retardation. Methodological and practical considerations related to safety of asthma medications in pregnancy and management of gestational asthma are discussed.

A comprehensive analysis of adverse obstetric and pediatric complications in women with asthma

RATIONALE

Previous studies have raised concern that women with asthma have increased risks of adverse obstetric and pediatric complications, but these have generally been underpowered.

OBJECTIVES

To quantify risks of major adverse pregnancy outcomes and obstetric complications in women with and without asthma.

METHODS

We extracted information on 281,019 pregnancies from the Health Improvement Network database between 1988 and 2004. We analyzed the data using logistic regression.

MEASUREMENTS AND MAIN RESULTS

In 37,585 pregnancies of women with asthma compared with 243,434 pregnancies of women without asthma, risks of stillbirth and therapeutic abortion were similar; however, the risk of miscarriage was slightly higher (odds ratio [OR], 1.10; 95% confidence interval [CI], 1.06-1.13). Risks of most obstetric complications (placental abruption, placental insufficiency, placenta previa, preeclampsia, hypertension, gestational diabetes, thyroid disorders in pregnancy, and assisted delivery) were not higher in pregnancies of women with asthma compared with those without asthma, with the exception of increases in antepartum (OR, 1.20; 95% CI, 1.08-1.34) or postpartum (OR, 1.38; 95% CI, 1.21-1.57) hemorrhage, anemia (OR, 1.06; 95% CI, 1.01-1.12), depression (OR, 1.52; 95% CI, 1.36-1.69), and caesarean section (OR, 1.11; 95% CI, 1.07-1.16). Risks of miscarriage, depression, and caesarean section increased moderately in women with more severe asthma and previous asthma exacerbations.

CONCLUSIONS

We found some increased risks in women with asthma that need to be considered in the future; however, our results indicate that women with asthma have similar reproductive risks compared with women without asthma in the general population for most of the range of outcomes studied.

Safety of leukotriene receptor antagonists in pregnancy

BACKGROUND

Asthma is a chronic disorder that affects about 8% of pregnant women and may complicate pregnancy. Adequate asthma therapy in pregnancy is crucial but challenging because of safety concerns for the fetus.

OBJECTIVE

To evaluate the safety of gestational asthma therapy with leukotriene receptor antagonists (LTRAs) for the mother and fetus/newborn.

METHODS

Subjects were participants of the Organization of Teratology Information Specialists Asthma Medications in Pregnancy Study. Perinatal outcomes among 96 women who took LTRAs (montelukast or zafirlukast) were compared with women who exclusively took short-acting beta(2)-agonists (n = 122) and women without asthma (n = 346).

RESULTS

Use of LTRAs was not associated with an increased risk of pregnancy loss, gestational diabetes, preeclampsia, low maternal weight gain, preterm delivery, low Apgar scores, or reduced measures of birth length and head circumference in infants (P > .05). Slightly decreased birth weight in infants born to LTRA users could be attributed to maternal asthma severity/control. The birth prevalence of major structural defects in the LTRA group (5.95%) was significantly higher compared with controls without asthma (P = .007), but not different from the comparison group with asthma (P = .524). Furthermore, the defects observed in the LTRA group did not represent a consistent pattern.

CONCLUSIONS

Use of LTRAs in pregnancy was not associated with a specific pattern of major structural anomalies in offspring or a large risk of other adverse perinatal outcomes.

CLINICAL IMPLICATIONS

This study suggests that LTRAs do not appear to be a major human teratogen; however, results should be interpreted with caution because of limited sample size.

The safety of asthma medications during pregnancy

This article reviews the literature on asthma or use of antiasthmatic drugs during pregnancy, the impact on pregnancy and delivery outcome, and on the infant born. Some anomalies have been demonstrated. It is unclear if these are due to asthma or are the effect of antiasthma drug use. The former explanation appears to be most likely, and the outcome appears to co-vary with the severity of the disease. Therefore, an adequate therapy of asthma is important during pregnancy, and although a small increase in certain congenital malformations may exist, this is of little significance for the individual patient. Further efforts should be made to isolate the possible specific effects of antiasthmatic drugs, notably for recent additions to the therapeutic arsenal.

Asthma exacerbations during pregnancy: incidence and association with adverse pregnancy outcomes

Exacerbations of asthma during pregnancy represent a significant clinical problem and may be related to poor pregnancy outcomes. A systematic review of the literature was conducted for publications related to exacerbations during pregnancy. Four studies with a control group (no asthma) and two groups of women with asthma (exacerbation, no exacerbation) were included in meta-analyses using fixed effects models. During pregnancy, exacerbations of asthma which require medical intervention occur in about 20% of women, with approximately 6% of women being admitted to hospital. Exacerbations during pregnancy occur primarily in the late second trimester; the major triggers are viral infection and non-adherence to inhaled corticosteroid medication. Women who have a severe exacerbation during pregnancy are at a significantly increased risk of having a low birth weight baby compared with women without asthma. No significant associations between exacerbations during pregnancy and preterm delivery or pre-eclampsia were identified. Inhaled corticosteroid use may reduce the risk of exacerbations during pregnancy. Pregnant women may be less likely to receive oral steroids for the emergency management of asthma. The effective management and prevention of asthma exacerbations during pregnancy is important for the health of both the mother and fetus.

Association of Asthma Diagnosis, Severity, Symptoms, and Treatment With Risk of Preeclampsia

OBJECTIVE

Existing studies relating asthma and preeclampsia provide conflicting results, perhaps due to differences in study populations, varying definitions of asthma, and inadequate control for confounding, particularly asthma medication use. This prospective study examines associations between aspects of asthma (diagnosis, severity, symptoms, and medication use) and risk of preeclampsia.

METHODS

A total of 1,708 pregnant women, of whom 656 had asthma diagnosis and 1,052 had no asthma diagnosis, were included in this analysis. Asthma symptoms, treatment, and severity were classified according to Global Initiative for Asthma guidelines. Hospital records were abstracted, and strict criteria were applied to classify women as preeclamptic based on National Heart, Lung, and Blood Institute guidelines.

RESULTS

There were 568 of 656 women with diagnosed asthma and 353 of 1,052 women without asthma diagnosis who had symptoms or took asthma medication during pregnancy. Separate adjusted logistic regression models were run for different measures of asthma status: 1) asthma diagnosis; 2) overall Global Initiative for Asthma severity; 3) Global Initiative for Asthma symptom and treatment steps; and 4) Global Initiative for Asthma symptom step and medication type. Women at increased risk of preeclampsia were those classified as Global Initiative for Asthma symptom step 3/4 compared with no symptoms (odds ratio 3.36, 95% confidence interval 1.24-9.14) and theophylline users (odds ratio 1.16 for every dose/month increase in use, 95% confidence interval 1.02-1.33). In contrast, neither a history of physician-diagnosed asthma nor Global Initiative for Asthma treatment step was associated with preeclampsia status.

CONCLUSION

Our findings suggest that women with moderate to severe asthma symptoms, regardless of asthma diagnosis or treatment, are at increased risk of preeclampsia compared with women with no symptoms.

Risk and risk assessment in pregnancy – do we scare because we care?

OBJECTIVE

To assess whether being labelled 'high-risk' affects women's psychosocial state in pregnancy.

DESIGN

Prospective, cross-sectional, non-experimental, case-control study.

SETTING

a large city in Germany.

PARTICIPANTS

Women between 22 and 41 weeks gestation were identified at antenatal classes and invited to participate in the study. Of the 147 women who were given a questionnaire, 82% (122) responded but only 75% (111) were eligible for inclusion in the study. Of these 111 women, 57 were classified as 'labelled high-risk' and 54 as 'no-risk' according to the risks documented in their antenatal records.

MEASUREMENTS

Women's psychosocial state was assessed using a validated, anonymous, self-completed questionnaire, the Abbreviated Scale for the Assessment of Psychosocial State in Pregnancy (Goldenberg et al. 1997). Analysis of covariance (ANCOVA) was performed to test the effect of the risk label on psychosocial state. The effect of other variables, such as parity or education, was also tested.

FINDINGS

The effect of the risk label on psychosocial state after adjusting for age was statistically significant (R(2)=0.07, F=7.59, df=1, p=0.001). No significant differences were found for the other independent variables. The data showed that a large number of women had one or more risk factors and that 71% were booked for obstetrician-led care. A high variability in obstetrician's documentation of women's risk factors was also found.

CONCLUSION

The data suggest that labelling women to be 'at risk' may negatively affect their psychosocial state. The findings highlight the need to re-evaluate the risk catalogue in the German antenatal record (Mutterpass) as well as the German maternity guidelines (Mutterschaftsrichtlinien). Although this study was conducted within the German system of antenatal care, the findings raise questions about the effects of risk labelling in maternity care wherever it is practised. Further research is needed to assess women's psychosocial state in a more representative sample, to explore women's experiences and satisfaction with the practice of risk assessment and to investigate the reasons for the high variability in documenting women's risk factors.