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

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.

Safety of Biological Therapies for Severe Asthma: An Analysis of Suspected Adverse Reactions Reported in the WHO Pharmacovigilance Database

BACKGROUND

The management of uncontrolled severe asthma has greatly improved since the advent of novel biologic therapies. Up to August 2022, five biologics have been approved for the type 2 asthma phenotype: anti-IgE (omalizumab), anti-IL5 (mepolizumab, reslizumab, benralizumab), and anti-IL4 (dupilumab) monoclonal antibodies. These drugs are usually well tolerated, although long-term safety information is limited, and some adverse events have not yet been fully characterized. Spontaneous reporting systems represent the cornerstone for the detection of potential signals and evaluation of the real-world safety of all marketed drugs.

OBJECTIVE

The aim of this study was to provide an overview of safety data of biologics for severe asthma using VigiBase, the World Health Organization global pharmacovigilance database.

METHODS

We selected all de-duplicated individual case safety reports (ICSRs) attributed to five approved biologics for severe asthma in VigiBase, up to 31st August 2022 (omalizumab, mepolizumab, reslizumab, benralizumab and dupilumab). Descriptive frequency analyses of ICSRs were carried out both as a whole class and as individual products. Reporting odds ratios (ROR) with 95% confidence intervals (CIs) were used as the measure of disproportionality for suspected adverse drug reactions (ADRs) associated with the study drugs compared with either all other suspected drugs (Reference Group 1, RG1) or inhaled corticosteroids plus long-acting β-agonists (ICSs/LABAs) (Reference Group 2, RG2) or with oral corticosteroids (OCSs) (Reference Group 3, RG3).

RESULTS

Overall, 31,724,381 ICSRs were identified in VigiBase and 167,282 (0.5%) were related to study drugs; the remaining reports were considered as RG1. Stratifying all biologic-related ICSRs by therapeutic indication, around 29.4% (n = 48,440) concerned asthma use; omalizumab was mainly indicated as the suspected drug (n = 20,501), followed by dupilumab, mepolizumab, benralizumab and reslizumab. Most asthma ICSRs concerned adults (57%) and women (64.1%). Asthma biologics showed a higher frequency of serious suspected ADR reporting than RG1 (41.3% vs 32.3%). The most reported suspected ADRs included asthma, dyspnea, product use issue, drug ineffective, cough, headache, fatigue and wheezing. Asthma biologics were disproportionally associated with several unknown or less documented adverse events, such as malignancies, pulmonary embolism and deep vein thrombosis with omalizumab; alopecia and lichen planus with dupilumab; alopecia and herpes infections with mepolizumab; alopecia, herpes zoster and eosinophilic granulomatosis with polyangiitis related to benralizumab; and alopecia with reslizumab.

CONCLUSIONS

The most frequently reported suspected ADRs of asthma biologics in VigiBase confirmed the presence of well-known adverse effects such as general disorders, injection-site reactions, nasopharyngitis, headache and hypersensitivity, while some others (e.g. asthma reactivation or therapeutic failure) could be ascribed to the indication of use. Moreover, the analysis of signals of disproportionate reporting suggests the presence of malignancies, effects on the cardiovascular system, alopecia and autoimmune conditions, requiring further assessment and investigation.

Asthma in Pregnancy: A Critical Review of Impact, Management, and Outcomes

Asthma is a common chronic respiratory condition that can significantly impact the health of pregnant women and their developing fetuses. This comprehensive review provides insights into the prevalence of asthma in pregnant women, the physiological changes during pregnancy, and the multifaceted impact of asthma on maternal and fetal health. It emphasizes the importance of proper asthma diagnosis, medication management, and the development of personalized asthma action plans during pregnancy. Lifestyle modifications, trigger avoidance, and stress reduction are essential to effective management. Healthcare providers are pivotal in educating, monitoring, and individualized care to ensure optimal asthma control. The review underscores the critical significance of managing asthma during pregnancy, as it improves maternal and fetal outcomes and potentially influences long-term health for both mother and child. Future directions in this field involve ongoing research, personalized treatment, early intervention, and precision medicine to enhance the understanding and care of asthma during pregnancy.

Implementation of the BC Congenital Anomalies Surveillance System (BCCASS)

SETTING

Congenital anomalies (CAs) can cause lifelong morbidity and accounted for 23.2% of infant deaths from 2003 to 2007. In British Columbia (BC), surveillance of CAs has been irregular since the early 2000s. To enhance CAs surveillance in BC, the Public Health Agency of Canada has provided funding for the implementation of the BC Congenital Anomalies Surveillance System (BCCASS).

INTERVENTION

BCCASS is a population-based surveillance system. The system leverages existing administrative data sources that capture information regarding vital events, disease status, drug prescription, and healthcare utilization. The system uses a series of algorithms to capture specific CAs diagnoses, some of which are further validated with the support of the Provincial Advisory Committee. This Advisory Committee is a multi-stakeholder coalition that includes the BC Office of the Provincial Health Officer, subject matter experts, data partners, users, and academia, and acts to provide support, expertise, and strategic guidance to BCCASS.

OUTCOMES

Through BCCASS, prevalence and historical trends for 35 CAs in BC are available. Information pertaining to maternal place of residence, risk, and protective factors can be used for association studies such as links to environmental hazards and cluster analysis.

IMPLICATIONS

BCCASS is a cost-effective and sustainable system that leverages existing data sources necessary to understand the overall burden of CAs across the BC population. This is fundamental to support data-driven decisions around policy development, program planning, and evaluation of preventive measures. Strong coalitions with stakeholders are instrumental to ensure successful implementation and expansion in the future.

What is safe enough - asthma in pregnancy - a review of current literature and recommendations

Background

Although asthma is one of the most serious diseases causing complications during pregnancy, half of the women discontinue therapy thus diminishing the control of the disease, mostly due to the inadequate education and fear of adverse events. Sadly, this is sometimes encouraged by insufficiently educated physicians. Since the incidence and the prevalence of asthma is increasing, it is important to arouse the importance of proper asthma therapy during pregnancy. Inadequate therapy, as well as interrupting or discontinuing therapy, may result in adverse perinatal outcomes for both mother and child.

Main body

The main goal of asthma control during pregnancy is control of symptoms and prevention of exacerbations, same as in every asthmatic, but even more important. Maintaining optimal lung function, as well as regular daily activities, ensures maintenance of optimal fetal oxygenation. The therapy should be adapted depending on the frequency and severity of daily and nocturnal symptoms, demand for reliever therapy, by the limitations in everyday activities and the frequency of emergency asthma-related hospitalizations. Pre-conceptual education and therapy are very important and should be supported by an asthma action plan adjusted for the period of pregnancy. It is very important to note that most of the drugs used before pregnancy can be safely continued during pregnancy. Pharmacological and non-pharmacological therapy should be used in parallel. Pregnant women should be informed about the nature of the disease, therapy used during pregnancy, possible complications, avoidance of triggers, proper administration of therapy and, most important, why should the therapy be continued throughout the pregnancy on individual basis. Although drug treatment should be based on using drugs with less harm risk, if control of severe symptoms is needed to be achieved in order to protect both mother and child, any anti-asthmatic drug would have the beneficial benefit/harm ratio.

Conclusion

There is no solid evidence that asthma treatment during pregnancy causes adverse outcomes for the mother and child but for many, especially new drugs, there is not enough data gathered. On the other hand, harmfulness of uncontrolled asthma during pregnancy is well documented so every effort should be put on preserving good control of asthma during pregnancy.

Uncontrolled maternal chronic respiratory diseases in pregnancy: A new potential risk factor suggested to be associated with anorectal malformations in offspring

BACKGROUND

Chronic respiratory diseases and use of antiasthmatic medication during pregnancy may both play a role in the etiology of congenital anorectal malformations (ARM). However, it is unclear, whether the medication use or the underlying condition would be responsible. Therefore, our aim was to unravel the role of maternal chronic respiratory diseases from that of antiasthmatic medication in the etiology of ARM.

METHODS

We obtained 412 ARM patients and 2,137 population-based controls from the Dutch AGORA data- and biobank. We used maternal questionnaires and follow-up telephone interviews to obtain information on chronic respiratory diseases, antiasthmatic medication use, and potential confounders. Multivariable logistic regression analyses were performed to estimate odds ratios (ORs) with 95% confidence intervals (95% CI).

RESULTS

We observed higher risk estimates among women with chronic respiratory diseases with and without medication use (1.4 [0.8-2.7] and 2.0 [0.8-5.0]), both in comparison to women without a chronic respiratory disease and without medication use. Furthermore, increased ORs of ARM were found for women using rescue medication (2.4 [0.8-7.3]) or a combination of maintenance and rescue medication (2.5 [0.9-6.7]). In addition, increased risk estimates were observed for women having nonallergic triggers (2.5 [1.0-6.3]) or experiencing exacerbations during the periconceptional period (3.5 [1.4-8.6]).

CONCLUSIONS

Although the 95% CIs of most associations include the null value, the risk estimates all point towards an association between uncontrolled chronic respiratory disease, instead of antiasthmatic medication use, with ARM in offspring. Further in-depth studies towards mechanisms of this newly identified risk factor are warranted.

Risk of childhood cerebral palsy following prenatal exposure to ß2-adrenergic receptor agonist: A nationwide cohort study

Background

Cerebral palsy (CP) is the most common physical developmental disability in childhood with a prevalence of 2 to 3 per 1000 live births. β2-adrenoreceptor agonist (β2AA) are widely used for the treatment of asthma. Maternal use of β2AAs may increase the risk of adverse neuro-psychiatric health outcomes in the offspring. No study, however, has evaluated the effect of prenatal exposure to β2AAs on the risk of CP.

Objective

To examine the association between prenatal exposure to β2AAs and the risk of childhood cerebral palsy.

Methods

This population-based cohort study included all live singleton births in Denmark from January 1, 1997 to December 31, 2003. The information on outpatient prescriptions of β2AAs was extracted from Danish National Prescription Registry. Children born to mothers who used β2AAs from 30 days before pregnancy until delivery were categorized as the exposed. To differentiate the effect of β2AAs from the underlying indications, the exposure window was further extended to 2 years before pregnancy and the exposed groups were re-defined to represent different periods of exposure to maternal use of β2AAs (use only before pregnancy, use only during pregnancy, and use both before and during pregnancy). Cases of CP were identified from the Danish Cerebral Palsy Register. Logistic regression was used to estimate incidence odds ratio (OR) of CP.

Results

Among all the 442,278 singletons, 19,616 (4.44%) were exposed to β2AAs in utero (from 30 days before pregnancy until delivery). The risk of childhood CP was 0.21% in exposed and 0.19% in unexposed group, yielding an adjusted OR (aOR) 1.12 (95% confidence interval (CI): 0.82, 1.53). When extending the exposure time window to 2 years prior to pregnancy, no overall significant association was observed regardless of the exposure period. However, an increased risk of CP (aOR = 1.41, 95%CI: 0.92, 2.18) for maternal β2AAs use during pregnancy was observed in female offspring, especially in those born at term (aOR = 1.65, 95%CI: 1.02, 2.67). This increase was mainly attributed to an increased risk in those born to mothers who used β2AAs both before and during pregnancy (aOR = 1.81, 95%CI: 0.99, 3.33).

Conclusions

We observed an association between maternal β2AAs use during pregnancy and an increased risk of CP in female offspring, but we could not rule out confounding by the underlying indications for β2AAs.

Maternal drug use and the risk of anorectal malformations: systematic review and meta-analysis

Background

Origin of anorectal malformations (ARM) are considered multifactorial. Several genetic and non-genetic risk factors are discussed in literature. Maternal periconceptional medical drug use as possible risk factor, however, has not been reviewed systematically.

Methods

Studies published between 1977 and April 2017 were reviewed through systematic search in PubMed, ISI Web of Knowledge and Scopus databases. Furthermore, related and cross-referencing publications were reviewed. Pooled odds ratios (95% confidence intervals) were determined to quantify associations of maternal periconceptional use of folic acid, multivitamins, anti-asthma medication (separated in any anti-asthma medication, inhaled corticosteroids and salbutamol), thyroid hormone supplements, psychiatric drugs (separated in antidepressants, any selective serotonin reuptake inhibitors [SSRI], sertraline, citalopram, fluoxetine, paroxetine, hypnotics and benzodiazepine) and aspirin with ARM using meta-analyses.

Results

Thirty-seven studies that reported on the association between maternal periconceptional drug intake and infants born with ARM were included in this review. These were conducted in the United States of America (n = 14), Sweden (n = 6), Hungary (n = 5), Germany (n = 3), the Netherlands (n = 3), Denmark (n = 2), France (n = 2), Norway (n = 1) and the UK (n = 1). However, only few of these studies reported on the same risk factors. Studies were heterogeneous with respect to case numbers, period ingestion of medical drug use, control selection and adjustment for covariates. Consistently increased risks were observed for any anti-asthma medication, and hypnotics and benzodiazepine, but not for folic acid, multivitamins, inhaled corticosteroids, salbutamol, thyroid hormone supplements, antidepressants, any SSRI, sertraline, citalopram, fluoxetine, paroxetine and aspirin. In meta-analyses, pooled odds ratios (95% confidence intervals) for any anti-asthma medication, and hypnotics and benzodiazepine were 1.64 (1.22–2.21), and 2.43 (1.03–5.73), respectively.

Conclusion

Evidence on maternal drug use before conception and during pregnancy as risk factor for ARM from epidemiological studies is still very limited. Nevertheless, the few available studies indicate any anti-asthma medication, and hypnotics and benzodiazepine to be associated with increased risks. Further, ideally large-scale multicenter and register-based studies are needed to clarify the role of maternal drug intake for the development of ARM.

The Impact of Different Case Ascertainment Definitions on the Prevalence of Major Congenital Malformations and their Association with Asthma During Pregnancy

Objectives To compare the prevalence of major malformations using different case ascertainment definitions and to evaluate their impact on maternal asthma-major malformations association. Methods A cohort of pregnancies with and without asthma between 1990 and 2010 was formed. We used two classification methods: the Two step Congenital Malformation Classification (TCMC) and the Canadian Congenital Anomalies Surveillance System (CCASS). Within each method, three case definitions were compared: (1) ≥1 diagnosis in the hospital database; (2) ≥1 diagnosis in the hospital database or ≥2 in the medical claims; and (3) ≥1 diagnosis in the hospital database or ≥1 in the medical claims. We calculated the prevalence of major malformations and adjusted odds ratios (aORs) for maternal asthma association. Results Of 467,946 pregnancies, 12.3 % were with active asthma. The prevalence estimates were: TCMC 5.10-7.08 % and CCASS 7.03-10.57 %. Asthma-major malformations association was weaker with the CCASS (aOR 1.14-1.20) versus TCMC (aOR 1.22-1.26). Discussion The case ascertainment definitions with ≥1 hospitalization are likely to be the most reliable in similar administrative databases. The case ascertainment definition had a considerable impact on the prevalence of major malformations, but hardly influenced the aORs. Future studies should formally assess the validity of the case ascertainment definitions and allow generalizability to other maternal exposures.

Risk of congenital anomalies after exposure to asthma medication in the first trimester of pregnancy - a cohort linkage study

Objective

To examine the effect of maternal exposure to asthma medications on the risk of congenital anomalies.

Design

Meta‐analysis of aggregated data from three cohort studies.

Setting

Linkage between healthcare databases and EUROCAT congenital anomaly registries.

Population

519 242 pregnancies in Norway (2004–2010), Wales (2000–2010) and Funen, Denmark (2000–2010).

Methods

Exposure defined as having at least one prescription for asthma medications issued (Wales) or dispensed (Norway, Denmark) from 91 days before to 91 days after the pregnancy start date. Odds ratios (ORs) were estimated separately for each register and combined in meta‐analyses.

Main outcome measures

ORs for all congenital anomalies and specific congenital anomalies.

Results

Overall exposure prevalence was 3.76%. For exposure to asthma medication in general, the adjusted OR (adjOR) for a major congenital anomaly was 1.21 (99% CI 1.09–1.34) after adjustment for maternal age and socioeconomic position. The OR of anal atresia was significantly increased in pregnancies exposed to inhaled corticosteroids (3.40; 99% CI 1.15–10.04). For severe congenital heart defects, an increased OR (1.97; 1.12–3.49) was associated with exposure to combination treatment with inhaled corticosteroids and long‐acting beta‐2‐agonists. Associations with renal dysplasia were driven by exposure to short‐acting beta‐2‐agonists (2.37; 1.20–4.67).

Conclusion

The increased risk of congenital anomalies for women taking asthma medication is small with little confounding by maternal age or socioeconomic status. The study confirmed the association of inhaled corticosteroids with anal atresia found in earlier research and found potential new associations with combination treatment. The potential new associations should be interpreted with caution due to the large number of comparisons undertaken.

Tweetable abstract

This cohort study found a small increased risk of congenital anomalies for women taking asthma medication.

This cohort study found a small increased risk of congenital anomalies for women taking asthma medication.

Safety of bronchodilators and corticosteroids for asthma during pregnancy: what we know and what we need to do better

Asthma is a common medical condition complicating pregnancy with potentially serious effects on pregnancy outcome. The aim of this review is to provide an update on efficacy and safety of asthma medications, primarily bronchodilators and corticosteroids, used during pregnancy with focus on pregnancy outcome, and, furthermore, to discuss limitations of available studies and point to possible improvements in future studies. A planned series of systematic searches was conducted using the PubMed database. Use of short-acting β2-agonists has generally been established as safe, and the few studies stating otherwise appear to have, perhaps critical, methodological limitations. The safety of long-acting β2-agonists remains to be further investigated, and the few available studies have methodological limitations and, therefore, provide no definite answers, although a very recent study supports the safety of add-on long-acting β2-agonists to inhaled corticosteroids. Inhaled corticosteroids are generally found to be safe, although further research is needed to investigate both the efficacy and safety of high dose therapy with inhaled corticosteroids. Studies have reported associations between the use of systemic corticosteroids and adverse perinatal outcomes, such as preterm birth, low birth weight, and pre-eclampsia. This must, however, be weighed against the potential serious impact of severe, uncontrolled asthma itself on pregnancy outcome. The main obstacle to a valid interpretation of several of the available studies is the inadequate stratification for asthma severity and control. Overall, asthma in itself and not just poor asthma control poses a greater risk to pregnancy outcomes than asthma medication. Nonetheless, more studies focusing on disentangling the effects of asthma alone and asthma medications are needed. Increased use of stratified risk assessments, taking the concept of asthma severity into greater consideration, is much warranted in future studies.

Validity of congenital malformation diagnostic codes recorded in Québec's administrative databases

PURPOSE

To assess the validity of the diagnostic codes of congenital malformations (CMs) recorded in two of Québec's administrative databases.

METHODS

A cohort of pregnancies and infants born to asthmatic and non-asthmatic women in 1990-2002 was reconstructed using Québec's administrative databases. From this cohort, we selected 269 infants with a CM and 144 without CM born to asthmatic women, together with 284 and 138 infants, respectively, born to non-asthmatic women. The diagnoses of CMs recorded in the databases were compared with the diagnoses written by the physicians in the infants' medical charts. The positive predictive values (PPV) and negative predictive values (NPV) for all, major, and several specific CMs were estimated.

RESULTS

The PPVs for all CMs and major CMs were 82.2% (95% confidence interval (CI): 78.5%-85.9%) and 78.1% (74.1%-82.1%), respectively, in the asthmatic group and were 79.2% (75.4%-83.1%) and 69.0% (64.6%-73.4%), respectively, in the non-asthmatic group. PPVs >80% were found for several specific CMs, including cardiac, cleft, and limb CMs in both groups. The NPV for any CM was 88.2% (95% CI: 85.1%-91.3%) in the asthmatic group and 94.2% (92.2%-96.2%) in the non-asthmatic group.

CONCLUSIONS

Québec's administrative databases are valid tools for epidemiological research of CMs. The results were similar between infants born to women with and without asthma.

Asthma and pregnancy

Asthma is probably the most common serious medical disorder that may complicate pregnancy. A third of pregnant women with asthma will experience worsening of their symptoms, a third will see improvement of their symptoms and a third will see no change. The primary goal is to maintain optimal control of asthma for maternal health and well-being as well as fetal maturation. Vital patient education should cover the use of controller medication, avoidance of asthma triggers and early treatment of asthma exacerbations. Proper asthma management should ideally be started in the preconception period. Since smoking is probably the most modifiable risk factor of asthma, pregnant woman should avoid active and passive smoking. Acute asthma exacerbation during the first trimester is associated with an increased risk of congenital malformations. Poorly controlled asthma is associated with low birth weight, preeclampsia, and preterm birth. Medications used for asthma control in the non-pregnant population are generally the same in pregnancy with a few exceptions. Inhaled corticosteroids (ICS) are the preferred controller therapy. Budesonide is the preferred ICS. Long-acting B-agonists (LABA) are the preferred add-on therapy to medium to high dose ICS. Major triggers for asthma exacerbations during pregnancy are viral infections and ICS nonadherence.

Impact of maternal asthma on perinatal outcomes: a two-stage sampling cohort study

There are conflicting results concerning the impact of maternal asthma during pregnancy on perinatal outcomes. The present study investigated the associations between maternal asthma during pregnancy and the risk of a small-for-gestational-age (SGA) infant, a low-birth-weight (LBW) infant, and preterm birth. A population-based cohort of 40,788 pregnancies from asthmatic and non-asthmatic women was reconstructed through the linking of three Quebec (Canada) administrative databases between 1990 and 2002. A two-stage sampling cohort design was used to collect additional information by way of a mailed questionnaire. The generalized estimation equation models were used to obtain adjusted odds ratios of SGA, LBW and preterm birth comparing asthmatic and non-asthmatic women. The cohort included 13,007 pregnancies from asthmatic and 27,781 pregnancies from non-asthmatic women. Final estimates showed that the odds of SGA (odds ratio: 1.27, 95% confidence interval: 1.14, 1.41), LBW (1.41: 1.22, 1.63) and preterm delivery (1.64: 1.46, 1.83) were significantly higher among asthmatic than non-asthmatic women. Mothers with asthma during pregnancy are more likely to have SGA, LBW, or preterm birth infants than non-asthmatic women. These results can be more easily generalized to women with lower socio-economic status since the cohort under represents women with high socio-economic status.

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.

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.