A population-based case-control study on the effect of bronchial asthma during pregnancy for congenital abnormalities of the offspring

Chronic Management of Asthma During Pregnancy

Asthma is one of the most common potentially serious medical problems to complicate pregnancy. Optimal management of asthma during pregnancy is thus important for both mother and baby. Treating asthmatic women requires understanding the effects of pregnancy on the course of asthma, and, conversely, the effects of asthma on pregnancy outcomes. Successful management also requires an understanding the barriers to asthma control in this population of patients. Evidence has shown that it is essential that the allergist-immunologist, obstetrician, and patient work as a team during pregnancy to achieve optimal maternal and neonatal outcomes.

The risk of congenital heart defects associated with corticosteroids use during the first trimester of pregnancy: a systematic review and meta-analysis

BACKGROUND

Prior studies have suggested that maternal corticosteroids exposure during the first trimester may be associated with an increased risk of congenital heart defects (CHDs) in offspring. However, the findings are discrepant. Moreover, a complete overview of the existing data in the literature is lacking. Our objective was to identify whether such an association exists.

METHODS AND RESULTS

Relevant studies were identified via searching PubMed, Web of Science, Embase, Chinese databases, and the Cochrane Library databases (search date July 15, 2021) and through checking the reference lists of retrieved articles. The overall pooled risk estimate was calculated using random-effect models. We used the GRADE approach to assess the overall strength of the evidence and the Newcastle-Ottawa Scale to assess study quality. Subgroup analyses were performed to evaluate the association within studies or samples with different characteristics. Sensitivity analyses were performed to assess the robustness of the results. Nine studies involving 1,901,599 participants were included in the final analysis. All studies were evaluated as high quality. In the meta-analysis, no statistically significant association was found between maternal corticosteroids exposure during the first trimester and increased risk of CHDs in offspring (OR = 1.06, 95% CI: 1.00-1.13, P = 0.06, low certainty of evidence). Additionally, we also did not find significant differences in subgroup analyses of corticosteroids exposure patterns, including oral corticosteroids exposure (OR = 1.23, 95% CI: 1.00-1.52), ointment corticosteroids exposure (OR = 1.03, 95% CI: 0.90-1.19), inhalation corticosteroids exposure (OR = 1.06, 95% CI: 0.96-1.17), topical corticosteroids or systemic corticosteroids exposure (OR = 0.95, 95% CI: 0.79-1.15), and nasal corticosteroids exposure (OR = 1.12, 95% CI: 0.80-1.57).

CONCLUSIONS

Our study does not find an association between maternal corticosteroids exposure during the first trimester and offspring CHDs. However, the existing evidence is of low quality; thus, long-term prospective cohort studies are warranted to verify the safety of corticosteroids in this population, with adequate adjustments for confounding variables.

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.

Pharmacotherapeutic management of asthma in pregnancy and the effect of sex hormones

INTRODUCTION

Asthma is a common medical condition that can frequently affect pregnancy, and thus optimal management of asthma in pregnancy is important for both mother and baby. This article reviews recent developments of asthma pharmacotherapy and provides emerging data on the safety of asthma controller medications and biological therapies in pregnancy. The authors highlight the clinical outcomes of asthma during pregnancy, and summarize emerging new data related to the influence of sex hormones and fetal sex on asthma severity.

AREAS COVERED

This review of asthma pharmacotherapy during pregnancy examines the recent guidelines and reports the most pertinent publications on safety data and asthma management.

EXPERT OPINION

Asthma management during pregnancy follows the same principles as that of non-pregnant asthma. The available data for most asthma medications are reassuring, however there is a lack of adequate safety data available because pregnant women are generally excluded from clinical trials. More clarity is needed in guidelines regarding the management of asthma in pregnancy, and high-quality randomized control trials are required to strengthen the evidence base and inform future guidelines. In particular, safety studies examining biological therapies in pregnant women with severe asthma are needed.

Asthma Medication Use and Risk of Birth Defects: National Birth Defects Prevention Study, 1997-2011

BACKGROUND

Evidence regarding associations between maternal asthma medication use and birth defects is mixed.

OBJECTIVE

Estimate associations between asthma medciation use and 52 birth defects using National Birth Defects Prevention Study data from 1997 to 2011.

METHODS

We compared self-reported maternal asthma medication use for 28,481 birth defect cases and 10,894 nonmalformed controls. We calculated adjusted odds ratios (95% CIs) to estimate the risk of birth defects associated with early pregnancy asthma medication use (the month before through the third month of pregnancy), controlling for maternal age, race/ethnicity, body mass index, smoking, folic acid-containing supplement use, and parity. We calculated risks by medication groupings: bronchodilators, anti-inflammatories, and both.

RESULTS

Overall, 1304 (5%) case and 449 (4%) control women reported early pregnancy asthma medication use. We observed an association between asthma medication use and longitudinal limb deficiency (1.81; 95% CI, 1.27-2.58). Early pregnancy bronchodilator-only use was associated with cleft palate (1.50; 95% CI, 1.11-2.02), cleft lip (1.58; 95% CI, 1.12-2.23), longitudinal limb deficiency (2.35; 95% CI, 1.55-3.54), and truncus arteriosus (2.48; 95% CI, 1.13-5.42). Although early pregnancy anti-inflammatory-only use was not associated with the birth defects studied, use of both medications was associated with biliary atresia (3.60; 95% CI, 1.55-8.35) and pulmonary atresia (2.50; 95% CI, 1.09-5.78).

CONCLUSIONS

Consistent with previous National Birth Defects Prevention Study analyses, asthma medication use was not associated with most birth defects examined, but we observed modest risks for bronchodilator use and several birth defects. Our findings support maintaining adequate asthma treatment during pregnancy, because early pregnancy asthma exacerbations have been associated with adverse birth outcomes, including birth defects.

Transfer of Montelukast into Human Milk During Lactation

AIM

The aim of this study was to determine levels of montelukast in human milk and to develop a simple, sensitive analytical method using mass spectrometry.

METHODS

Milk samples were collected from seven breastfeeding mothers, age 26-35 years, at 0, 1, 2, 4, 8, and 12 hours after oral ingestion of 10 mg montelukast. The samples were analyzed using a new Liquid Chromatography-Tandem Mass Spectrometry method. Area under the milk concentration time curve from zero to the time of the last sample (12 hours) was estimated by the linear trapezoidal rule.

RESULTS

Average montelukast levels (C_avg) in milk were 5.3 ng/mL, and the relative infant dose was 0.68% of the maternal dose. The maximum concentration (C_max) observed at 4 hours (Tmax) was 9.7 ng/mL.

CONCLUSION

The exposure to the infant seems to be very low, far below therapeutic ranges in an infant. Our data suggest that montelukast is probably safe to use in a breastfeeding mother.

Maternal asthma medication use during pregnancy and risk of congenital heart defects

BACKGROUND

Asthma affects 4% to 8% of pregnant women and studies suggest maternal asthma, particularly when uncontrolled, may be associated with adverse reproductive outcomes.

METHODS

We examined self-reported asthma medication use and the risk of congenital heart defects (CHD) in the National Birth Defects Prevention Study, a multi-center, population-based case-control study of selected major structural defects. We evaluated maternal use of bronchodilators and anti-inflammatories during the periconceptional period (1 month before conception through the first 3 pregnancy months) among 7638 infants with CHDs and 8106 nonmalformed controls with estimated delivery dates from 1997 to 2007. We used logistic regression to estimate odds ratios and 95% confidence intervals for 20 types of CHDs.

RESULTS

Among asthma medications reported during the periconceptional period among controls, albuterol accounted for 85.1% of all bronchodilator use, and fluticasone, prednisone, and montelukast accounted for 46.1%, 15.6%, and 14.9% of anti-inflammatory use, respectively. Of the women who reported bronchodilators during the periconceptional period, 71.1% reported use throughout pregnancy and only 29.4% reported concurrent use of an anti-inflammatory. We observed one statistically significant association between maternal bronchodilator use only and anomalous pulmonary venous return (odds ratio 2.3, 95% confidence interval 1.1-4.8) among numerous comparisons.

CONCLUSION

We did not observe statistically significant associations between the reported use of asthma medications during pregnancy and most specific types of CHDs. Despite limitations in our inability to evaluate asthma status and severity, our study suggests that maternal asthma medication use does not substantially, if at all, increase the risk of CHDs.

Genetic and nongenetic etiology of nonsyndromic anorectal malformations: a systematic review

Congenital anorectal malformations (ARMs) are one of the most frequently observed birth defects of the digestive system. However, their etiology remains elusive. Therefore, we aim to summarize and critically appraise all existing literature on the genetic and nongenetic etiology of nonsyndromic ARM and to conclude with unifying hypotheses and directions for future research. A structured literature search on English language human studies was conducted in PubMed and Embase up to October 1, 2013, resulting in 112 included articles. Research on the identification of genes underlying nonsyndromic ARM is remarkably scarce. Most studies were focused on screening of candidate genes for mutations or single-nucleotide polymorphisms, which did not yield any substantial evidence. Nongenetic factors fairly consistently found to be associated with ARM are assisted reproductive techniques, multiple pregnancy, preterm delivery, low birth weight, maternal overweight or obesity, and preexisting diabetes. This review provides indications for the involvement of both genes and nongenetic risk factors in the etiology of ARM. In future studies, large cohorts of patients with ARM from national and international collaborations are needed to acquire new hypotheses and knowledge through hypothesis-generating approaches. Challenges for future studies may also lie in the investigation of gene-gene and gene-environment interactions.

Circulating survivin levels in healthy and asthmatic pregnancy

BACKGROUND

Asthma is one of the most common conditions which complicate pregnancy. Pro- and anti-apoptotic mechanisms can be modulated by asthma accompanying pregnancy. Survivin, an anti-apoptotic protein has been implicated in the pathomechanism of asthma and also in the development of pathological pregnancies; however survivin has not been studied in pregnant asthmatics.

METHODS

Twenty-eight asthmatic pregnant (AP), 25 asthmatic non-pregnant (ANP), 21 healthy pregnant (HP) and 29 healthy non-pregnant (HNP) women were enrolled in this cross-sectional study. Plasma survivin concentration was determined by ELISA.

RESULTS

Plasma survivin was significantly lower in HP (1.64 /0-74.9/ pg/ml) than in HNP (24.6 /0-333.3/ pg/ml, p = 0.01). However, this difference was not observed between the asthmatic groups (p = 0.64). Similarly, there was no difference either between HNP and ANP (10.5 /0-215.4/ pg/ml, p = 0.23) or between HP and AP (13.9 /0-364.1/ pg/ml, p = 0.30) groups.

CONCLUSIONS

Decreased plasma survivin levels in physiological but not in asthmatic pregnancy may suggest that the normal apoptotic mechanisms are compromised in asthmatic gestation.

Beta2-agonists use during pregnancy and perinatal outcomes: a systematic review

BACKGROUND

Short and long-acting beta2-agonists (SABA and LABA) have a crucial role in asthma management during pregnancy, as stated in the current guidelines.

OBJECTIVE

To systematically review the evidence on beta2-agonists use during pregnancy and adverse perinatal outcomes.

DATA SOURCES AND STUDY SELECTION

Six databases were searched before January 1, 2013 for beta2-agonists use during pregnancy and congenital malformations, small for gestational age, mean and low birth weight, gestational age and preterm delivery. Original English language articles were included with no cut-off date. Quality assessment and post-hoc power calculations were performed.

RESULTS

Twenty-one original studies were identified. Four studies reported a significant increased risk of congenital malformations with SABA, while one study reported a significant decreased risk with high doses of SABA. One study reported a significant increased risk of congenital malformations with LABA and four studies reported a significant increased risk of congenital malformations with beta2-agonists (SABA and/or LABA). One study reported a decrease in birth weight centiles among LABA users.

LIMITATIONS

All studies reporting significant results, except two, used non-asthmatic women as reference group, making it difficult to differentiate between the effect of the disease from the one of the beta2-agonists. Non-significant results should be interpreted with caution due to the low statistical power of several studies.

CONCLUSION

Methodological limitations and lack of power of several studies prevent us to conclude on the perinatal safety of beta2-agonists. Until further evidence is available, physicians should continue prescribing them as recommended in the guidelines whenever needed to attain asthma control.

Lack of relationship between birth conditions and allergic disorders in Japanese children aged 3 years

BACKGROUND

The current cross-sectional study examined the associations between low birth weight (LBW), preterm birth, and small-for-gestational-age (SGA) and the prevalence of wheeze, asthma, and eczema in Japanese children aged 3 years.

METHODS

Study subjects were 2004 children. All data were obtained using a questionnaire. Outcomes were defined according to the criteria of the International Study of Asthma and Allergies in Childhood. Adjustment was made for sex, number of siblings, breastfeeding duration, paternal and maternal educational level, paternal and maternal history of allergic disorders, maternal smoking during pregnancy, secondhand smoke exposure at home, and gestational age at birth.

RESULTS

The prevalence of wheeze, asthma, and eczema in the previous 12 months were 22.1%, 9.0%, and 17.5%, respectively, and 8.4% were classified as LBW (<2500 g), 4.7% as preterm birth (<37 weeks), and 7.1% as SGA (<10th percentile). There were no significant associations between LBW, preterm birth, or SGA and the prevalence of wheeze, asthma, or eczema. A positive relationship between preterm birth and asthma was of borderline significance in children whose mothers had smoked during pregnancy (adjusted OR: 4.71 [95% CI: 0.97-21.39]), but not in those whose mothers had never smoked during pregnancy; the multiplicative interaction between preterm birth and maternal smoking during pregnancy with respect to asthma was significant (p = .04).

CONCLUSIONS

The current study failed to detect significant associations between birth conditions and allergic disorders. Nevertheless, we did find evidence for an interaction between preterm birth and maternal smoking during pregnancy affecting asthma.

Maternal asthma medication use and the risk of selected birth defects

OBJECTIVES

Approximately 4% to 12% of pregnant women have asthma; few studies have examined the effects of maternal asthma medication use on birth defects. We examined whether maternal asthma medication use during early pregnancy increased the risk of selected birth defects.

METHODS

National Birth Defects Prevention Study data for 2853 infants with 1 or more selected birth defects (diaphragmatic hernia, esophageal atresia, small intestinal atresia, anorectal atresia, neural tube defects, omphalocele, or limb deficiencies) and 6726 unaffected control infants delivered from October 1997 through December 2005 were analyzed. Mothers of cases and controls provided telephone interviews of medication use and additional potential risk factors. Exposure was defined as maternal periconceptional (1 month prior through the third month of pregnancy) asthma medication use (bronchodilator or anti-inflammatory). Associations between maternal periconceptional asthma medication use and individual major birth defects were estimated by using adjusted odds ratios (aOR) and 95% confidence intervals (95%CI).

RESULTS

No statistically significant associations were observed for maternal periconceptional asthma medication use and most defects studied; however, positive associations were observed between maternal asthma medication use and isolated esophageal atresia (bronchodilator use: aOR = 2.39, 95%CI = 1.23, 4.66), isolated anorectal atresia (anti-inflammatory use: aOR = 2.12, 95%CI = 1.09, 4.12), and omphalocele (bronchodilator and anti-inflammatory use: aOR = 4.13, 95%CI = 1.43, 11.95).

CONCLUSIONS

Positive associations were observed for anorectal atresia, esophageal atresia, and omphalocele and maternal periconceptional asthma medication use, but not for other defects studied. It is possible that observed associations may be chance findings or may be a result of maternal asthma severity and related hypoxia rather than medication use.

Asthma and rhinitis during pregnancy

Pregnancy may be complicated by new-onset or preexisting rhinitis, or asthma. This article reviews the recognition and management of rhinitis and asthma during pregnancy, as well as general principles of medication use during pregnancy. Asthma is one of the most common potentially serious medical problems to complicate pregnancy, and chronic rhinitis is even more common in pregnant women. Both conditions may substantially affect maternal quality of life and directly or indirectly affect the pregnancy. Optimal management of asthma and rhinitis during pregnancy is thus important for both mother and baby. This article reviews the assessment and management of rhinitis and asthma in pregnant women.

Maternal bronchodilator use and the risk of orofacial clefts

BACKGROUND

Few epidemiological studies have explored the relationship between orofacial clefts and bronchodilators. We assessed whether mothers who used bronchodilators during early pregnancy were at an increased risk of delivering infants with orofacial clefts.

METHODS

We used National Birth Defects Prevention Study case-control data from mothers of 2711 infants with orofacial clefts and 6482 mothers of live born infants without birth defects, delivered during 1997 through 2005. Information on medication use from 3 months before pregnancy through delivery was collected using a standardized interview. Logistic regression was used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CIs) for maternal bronchodilator use during the periconceptional period (1 month before pregnancy through the third month of pregnancy) while controlling for other covariates.

RESULTS

We observed an association between maternal bronchodilator use during the periconceptional period and cleft lip only (CLO) (aOR = 1.77, 95% CI: 1.08-2.88). The risk of cleft palate only (CPO) (aOR = 1.53, 95% CI: 0.99-2.37) was elevated but was not statistically significant. No association was observed for maternal bronchodilator use and the risk of cleft lip with cleft palate (aOR = 0.78, 95% CI: 0.46-1.31). The most commonly used bronchodilator was albuterol (88.7%). Maternal albuterol use was associated with CLO (aOR = 1.79, 95% CI: 1.07-2.99) and CPO (aOR = 1.65, 95% CI: 1.06-2.58).

CONCLUSIONS

We observed a statistically significant association between maternal bronchodilator use during the periconceptional period and the risk of CLO after controlling for other risk factors. It is unclear whether the increased odds ratios observed in this study are due to the bronchodilators, the severity of asthma, or both, or to chance alone. Further studies to disentangle the role of asthma or asthma medications would help clarify these findings.

Beta2-agonists use during pregnancy and the risk of congenital malformations

BACKGROUND

Treatment of asthma symptoms during pregnancy is crucial for maternal and fetal health. Short-acting beta2-agonists (SABA) are frequently used as rescue medications and long-acting beta2-agonists (LABA) are used as add-on controller therapy for asthma during pregnancy.

OBJECTIVE

The objective of this study was to investigate the association between exposure to SABA and LABA in the first trimester of pregnancy and the risk of congenital malformations among women with asthma.

METHODS

A cohort of pregnancies from women with asthma was formed through linkage of three administrative databases from Québec, Canada. The primary outcomes were major and any congenital malformations. The primary exposures were exposure to SABA and LABA during the first trimester, while secondary exposure was weekly SABA doses. The associations between congenital malformations (any, major, and specific) and SABA and LABA exposure were assessed with generalized estimating equations models.

RESULTS

From a group of 13,117 pregnancies, we identified 1242 and 762 infants with any (9.5%) and major (5.8%) congenital malformations, respectively. The adjusted odds ratios (95% confidence interval [CI]) for any malformations associated with the use of SABA and LABA were 1.04 (95% CI, 0.92-1.17) and 1.37 (95% CI, 0.92-2.17), respectively. The corresponding figures were 0.93 (95% CI, 0.80-1.08) and 1.31 (95% CI, 0.74-2.31) for major malformations. Significant increased risks of major "cardiac" and major "other and unspecified" congenital malformations were observed with LABA use.

CONCLUSION

Our study supports the evidence of SABA safety during pregnancy, but more research is required to assess whether the increased risk of malformations among LABA users is due to the medication, bias by asthma severity, or chance alone.

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.

Montelukast use during pregnancy: a multicentre, prospective, comparative study of infant outcomes

BACKGROUND

Montelukast (Singulair) is a selective leukotriene receptor antagonist (LTRA) indicated for the maintenance treatment of asthma. Currently, there are limited prospective, comparative studies in the literature examining the safety of montelukast use in pregnancy.

OBJECTIVES

The primary objective of this study was to determine whether exposure to montelukast during pregnancy increases the rate of major malformations above the 1–3% baseline risk or the rate of other adverse effects.

METHODS

Pregnant women taking montelukast were enrolled in the study from six teratogen information services around the world. These women were compared to two other groups of women: (1) disease-matched, who used inhalers for a similar indication and (2) women not diagnosed with asthma and not exposed to any known teratogens. The primary outcome was major malformations and secondary endpoints included spontaneous abortion, fetal distress, gestational age at birth and birth weight.

RESULTS

Out of 180 montelukast-exposed pregnancies, there were 160 live births including three sets of twins, 20 spontaneous abortions, 2 elective abortions and 1 major malformation reported. The mean birth weight was lower (3,214 ± 685 g) compared to controls [3,356 ± 657 (disease-matched) and 3,424 ± 551 (exposed to non-teratogens), P = 0.038] and the gestational age was shorter [37.8 ± 3.1 weeks (montelukast) and 37.6 ± 4.4 (disease-matched) versus 39.3 ± 2.4 weeks (exposed to non-teratogens), P = 0.045]. About 25% of the newborns had fetal distress, a higher rate than controls (P = 0.007). However, upon sub-analysis of women who continued the drug until delivery, only birth-weight difference (304 g) remained significant.

CONCLUSIONS

Montelukast does not appear to increase the baseline rate of major malformations. The lower birth weight in both asthma groups is most likely associated with the severity of the maternal condition.

Asthma in pregnancy--immunological changes and clinical management

Asthma is one of the most common diseases complicating pregnancy and a risk factor for several maternal and fetal complications, posing a special challenge for physicians treating asthmatic pregnant women. Asthma influences the outcome of pregnancy and - vice versa - pregnancy affects asthma severity with bidirectional immunological interactions that are currently being examined. Supporting pregnancy-induced immunotolerance is the observation that attenuation of allergic responses can be detected in controlled asthmatic pregnant patients. However, uncontrolled asthmatic pregnant women show significant asthma-associated immune reactions, such as diminished pregnancy specific regulatory T cell proliferation, that may - besides other factors - influence fetal growth. Uncontrolled, symptomatic asthma may increase the risk of adverse perinatal outcomes; thus adequate regular anti-asthmatic treatment resulting in optimal asthma control represents a vital need during pregnancy. This review summarizes immunological changes characterizing pregnancy in asthmatic women together with the clinical implications of asthma management during pregnancy.

Asthma in pregnancy - from immunology to clinical management

Asthma is one of the most common chronic medical conditions that may complicate pregnancy. Asthma influences the outcome of pregnancy and, vice versa, pregnancy affects asthma severity, but the underlying immunological mechanisms of this interaction are not fully understood. As a sign of pregnancy-induced immunotolerance, attenuation of allergic responses can be detected in controlled asthmatic pregnant patients; however non controlled asthmatic pregnant women show significant asthma-associated immune reactions that may, beside other factors, influence fetal growth. Generally, although uncontrolled asthma may increase the risk of adverse perinatal outcomes, women with well-controlled and adequately treated disease during pregnancy do not develop maternal or fetal complications.

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.

Exhaled nitric oxide in pregnant healthy and asthmatic women

BACKGROUND

Measurement of fractioned exhaled nitric oxide (FE(NO)) is useful for monitoring airway inflammation in asthma. Asthma is one of the most common diseases complicating pregnancy, and FE(NO) may be helpful for monitoring asthma in pregnancy. However, some physiological alterations of FE(NO) may be expected during healthy pregnancy due to vascular nitric oxide production. Until now no study assessed the level of FE(NO) in asthmatic pregnant patients.

OBJECTIVE

We aimed to assess the possible use and reproducibility of FE(NO) measurements in pregnant asthmatic women. We compared FE(NO) concentrations between four groups of subjects: healthy nonpregnant and pregnant females and asthmatic nonpregnant and pregnant patients. We also investigated the relationship between FE(NO) values and the level of asthma control in pregnant asthmatic patients.

METHODS

A total of 102 female subjects (35 healthy nonpregnant and 27 healthy pregnant females; 20 nonpregnant and 20 pregnant asthmatic women) were included in this cross-sectional study. Two FE(NO) measurements were performed in each subject using an electrochemical sensor based device (NIOX MINO, Aerocrine, Solna, Sweden). Data are given as median with range.

RESULTS

The repeatability of FE(NO) measurement was similar in pregnant and nonpregnant subjects. FE(NO) levels did not differ significantly between healthy pregnant versus nonpregnant subjects (16.0 [8, 31] vs. 16.0 [9, 35] ppb). FE(NO) levels were significantly increased in asthmatic women compared to healthy females (nonpregnant asthmatics: 38 [9, 54] ppb, p < 0.001 vs. healthy nonpregnant; pregnant asthmatic patients: 28 [10, 56] ppb; p < 0.05 vs. healthy pregnant).

CONCLUSIONS

FE(NO) level is not influenced by healthy pregnancy. In pregnant asthmatic patients FE(NO) level is elevated compared to healthy pregnant subjects and correlates with the level of asthma control. Further studies are required to assess the use of FE(NO) measurement to monitor asthma in this patient group.

Safety of inhaled budesonide: clinical manifestations of systemic corticosteroid-related adverse effects

Inhaled corticosteroid (ICS) therapy is central to the long-term management of asthma and is extensively used in the management of chronic obstructive pulmonary disease (COPD). While administration via inhalation limits systemic exposure compared with oral or injected corticosteroids and, therefore, the risk of systemic corticosteroid-related adverse effects, concerns over the long-term safety of ICS persist. The assessment of the long-term effects of ICS therapy requires considerable research effort over years or even decades. Surrogate markers/predictors for clinical endpoints such as adrenal crisis, reduced final height and fractures have been identified for use in relatively short-term studies. However, the predictive value of such markers remains questionable.Inhaled budesonide has been available since the early 1980s and there is a considerable evidence base investigating the safety of this agent. To assess the long-term safety of inhaled budesonide therapy in terms of the actual incidence of the clinical endpoints adrenal crisis/insufficiency, reduced final height, fractures and pregnancy complications, we undertook a review of the scientific literature. The external databases BIOSIS, Cochrane Central Register of Controlled Trials, Current Contents, EMBASE, International Pharmaceutical Abstracts and MEDLINE were searched, in addition to AstraZeneca's internal product literature database Planet, up to 29 February 2008. Only original articles of epidemiological studies, national surveys, clinical trials and case reports concerning inhaled budesonide were included.Eight surveys of adrenal crisis were found. The only survey with specified criteria for diagnosis involved 2912 paediatricians and endocrinologists and revealed 33 patients with adrenal crisis associated with ICS therapy; only one patient used budesonide (in co-treatment with fluticasone propionate). In addition, 14 case reports of adrenal crisis in budesonide-treated patients were found. In only two of these, budesonide was used at recommended doses and in the absence of interacting medication.Three retrospective studies and one prospective study assessing final height were found. None of them showed any reduced final height in patients receiving inhaled budesonide during childhood or adolescence.Seventeen epidemiological studies investigating the risk of fractures were found. When adjusting for confounding factors, they did not provide any unequivocal data for an increased fracture risk with budesonide. Four prospective placebo-controlled clinical trials of 2-6 years duration with inhaled budesonide in patients with asthma or COPD were found. None of the studies identified any association between inhaled budesonide and increased risk for fractures.Four studies using data from the Swedish birth and health registries showed there was no increased risk for congenital malformations, cardiovascular defects, decreased gestational age, birth weight or birth length among infants born to women using inhaled budesonide during pregnancy compared with the general population. This was confirmed by five observational studies in Australia, Canada, Hungary, Japan and the US. Similarly, one randomized clinical trial comparing pregnancy outcomes among asthma patients receiving inhaled budesonide or placebo did not demonstrate any difference in outcome of pregnancy.In summary, based on 25 years of experience with different doses and in different populations, inhaled budesonide therapy only in very rare cases appears to be associated with an increased risk of adrenal crisis, reduction in final height, increases in the number of fractures or complications during pregnancy.

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.