A population-based prescription study of asthma drugs during pregnancy: changing the intensity of asthma therapy and perinatal outcomes

Use of Asthma Medication During Gestation and Risk of Specific Congenital Anomalies

Poorly controlled asthma can affect neonatal outcomes including congenital anomalies, which can be reduced with appropriate asthma care during pregnancy. Although there is a concern regarding the safety of asthma medication use during pregnancy and congenital anomalies, the risk of uncontrolled asthma outweighs any potential risks of controller and reliever medication use. Patient education before and during pregnancy is critical to ensure good compliance to therapy and reduce the risk of poor asthma control.

Asthma in a prospective cohort of rural pregnant women from Sri Lanka: Need for better care during the pre-conceptional and antenatal period

Objectives

To describe the epidemiology and the effect of asthma on pregnancy outcomes in pregnant women from a rural geography.

Methods

We conducted a prospective cohort study in Anuradhapura district, Sri Lanka enrolling all eligible pregnant women registered in the maternal care program. An interviewer-administered questionnaire-based symptom analysis and clinical assessment was conducted in the first and second trimesters.

Results

We recruited 3374 pregnant women aged 15–48 years at conception. Self-reported physician-diagnosed asthma prevalence was 6.6% (n = 223) with only 41.7% (n = 93) on regular medical follow-up for asthma. The prevalence of wheeze reduced from pre-pregnancy (67.0%) to the first (46.4%) and second trimesters (47.7%; p<0.01). Of the 73 asthmatic women who did not have wheeze in the last 3 months preceding pregnancy, new-onset wheeze was reported by 6(8.2%) and 12(16.4%) in the first and second trimester, respectively. Pregnant women who sought medical care for asthma in the private sector had a lower likelihood of developing new-onset wheeze in the first trimester (p = 0.03; unadjusted OR = 0.94;95%CI 0.89–0.99). Thirty-four (33.3%) pregnant women had at least one hospital admission due to exacerbation of wheeze during the first and second trimester. The prevalence of low birth weight (16.0%) was higher among pregnant asthmatic women.

Conclusion

This study reports the high prevalence of asthma and asthma-associated pregnancy outcomes in women from a rural geography signifying the importance of targeted management.

Oral corticosteroid use during pregnancy and risk of preterm birth

OBJECTIVE

To evaluate the associations between oral corticosteroid (OCS) dose early and late in pregnancy and preterm birth (PTB) among women with RA.

METHODS

Pregnant women in the MotherToBaby Pregnancy Studies (2003-2014) with RA (n = 528) were included in the primary analysis. Information was collected by phone interview and from medical records. We estimated risk ratios (RR) for OCS dose trajectories and other disease-related medications before gestational day 140 and hazard ratios (HR) for time-varying exposures after gestational day 139.

RESULTS

PTB risk was 15.5% overall. Compared with no OCS, PTB risk was increased in high (adjusted (a)RR: 4.77 (95% CI: 2.76, 8.26)) and medium (aRR: 1.81 (95% CI: 1.10, 2.97)) cumulative OCS dose trajectories during the first 139 gestational days. The low cumulative trajectory group was associated with an increased risk of PTB that was not statistically significant (aRR: 1.38 (95% CI: 0.79, 2.38)), and DMARDs were not associated with PTB (biologic DMARDs aHR: 1.08 (95% CI: 0.70, 1.66); non-biologic DMARDs aHR: 0.87 (95% CI: 0.55, 1.38)). OCS exposure to ⩾10 mg of prednisone equivalent daily dose after gestational day 139 vs none was associated with increased PTB rate (aHR: 2.45 (95% CI: 1.32, 4.56)), whereas <10 mg was associated with a modestly increased rate of PTB that was not statistically significant (aHR: 1.18 (95% CI: 0.60, 2.30)).

CONCLUSION

Higher OCS doses vs no OCS use, both earlier and later in pregnancy, were associated with an increase in PTB among women with RA.

Oral Corticosteroids and Risk of Preterm Birth in the California Medicaid Program

BACKGROUND

There is limited information regarding the impact of dose and gestational timing of oral corticosteroid (OCS) use on preterm birth (PTB), especially among women with asthma.

OBJECTIVES

To evaluate OCS dose and timing on PTB for asthma and, as a comparison, systemic lupus erythematosus (SLE).

METHODS

We used health care data from California Medicaid enrollees linked to birth certificates (2007-2013), identifying women with asthma (n = 22,084) and SLE (n = 1174). We estimated risk ratios (RR) for OCS cumulative dose trajectories and other disease-related medications before gestational day 140 and hazard ratios (HR) for time-varying exposures after day 139.

RESULTS

For asthma, PTB risk was 14.0% for no OCS exposure and 14.3%, 16.8%, 20.5%, and 32.7% in low, medium, medium-high, and high cumulative dose trajectory groups, respectively, during the first 139 days. The high-dose group remained associated with PTB after adjustment (adjusted RR [aRR]: 1.46; 95% confidence interval [CI]: 1.00, 2.15). OCS dose after day 139 was not clearly associated with PTB, nor were controller medications. For SLE, PTB risk for no OCS exposure was 24.9%, and it was 39.1% in low- and 61.2% in high-dose trajectory groups. aRR were 1.80 (95% CI: 1.34, 2.40) for high and 1.24 (95% CI: 0.97, 1.58) for low groups. Only prednisone equivalent dose >20 mg/day after day 139 was associated with increased PTB (adjusted HR: 2.54; 95% CI: 1.60, 4.03).

CONCLUSIONS

For asthma, higher OCS doses early in pregnancy, but not later, were associated with increased PTB. For SLE, higher doses early and later in pregnancy were associated with PTB.

The Association Between Prenatal Exposure to Antidepressants and Autism: Some Research and Public Health Aspects

Use of antidepressants (ADs) in general, and in pregnant notwithstanding, has been increasing globally in recent decades. Associations with a wide range of adverse perinatal and childhood outcomes following prenatal ADs exposure have been observed in registry-based studies, with Autism Spectrum Disorders (ASD) frequently reported. Studies using animal models, sibling analyses, and negative control approaches, have linked dysfunctional serotonin metabolism with ASD, but did not convincingly tease apart the role of maternal mental health from that of ADs. As work to decipher the nature of the AD-ASD association continues, this review raises some public health concerns pertinent to a hypothetical conclusion that this association is causal, including the need to identify specific gestation periods with higher risk, the importance of precise assessment of the ASD potential prevention that might be attributed to AD discontinuation, and the estimation of risks associated with prenatal exposure to untreated depression.

Maternal asthma is associated with increased risk of perinatal mortality

Background

Asthma is the most common chronic disease during pregnancy and it may have influence on pregnancy outcome.

Objectives

Our goal was to assess the association between maternal asthma and the perinatal risks as well as possible effects of asthma medication.

Methods

The study was based on a nationwide Finnish register-based cohort between the years 1996 and 2012 in the Drug and Pregnancy Database. The register data comprised 962 405 singleton live and stillbirths, 898 333 (93.3%) pregnancies in mothers with neither confirmed asthma nor use of asthma medication (controls), and 26 674 (2.8%) pregnancies with confirmed maternal asthma. 71% of mothers with asthma used asthma medication. The diagnosis of asthma was based on the mothers’ right for subsidised medication which is carefully evaluated by strict criteria including pulmonary function testing. Odds ratio was used in comparison. Premature birth (PB), low birth weight, small for gestational age (SGA), neonatal death were the main outcome measures.

Results

Maternal asthma was associated with adjusted odds ratios (aORs) for perinatal mortality 1.24 (95% CI 1.05 to 1.46), preterm birth 1.18 (1.11 to 1.25), low birth weight 1.29 (1.21 to 1.37), fetal growth restriction (SGA) 1.32, (1.24 to 1.40), and asphyxia 1.09 (1.02 to 1.17). Asthma treatment reduced the increased risk of preterm birth aOR 0.85 (95% CI 0.76 to 0.96) but mothers with treated asthma had higher risks of fetal growth restriction (SGA) aOR 1.26 (1.10 to 1.45), and asphyxia aOR 1.37 (1.17 to 1.61) than mothers with untreated asthma.

Conclusion

Asthma is associated with increased risks of perinatal mortality, preterm birth, low birth weight, fetal growth restriction (SGA), and asphyxia. Asthma treatment reduces the risk of preterm delivery, but it does not seem to reduce other complications such as perinatal mortality.

On the use of the outcome variable "small for gestational age" when gestational age is a potential mediator: a maternal asthma perspective

BACKGROUND

The variable "small for gestational age," frequently defined as birth weight below the 10th percentile in a gestational age and sex-normalized population, is nowadays generally perceived as a more adequate measure than birth weight or low birth weight (birth weight < 2500 g) to capture fetal growth. However, the use of small for gestational age rather than birth weight or low birth weight as an outcome (dependent) variable may have important impacts on the interpretation of analyses aimed at estimating the causal effect of an exposure of interest on infants. We hypothesized potential differences in both types of effects estimated (direct or total) and in ability to control for confounding bias.

METHODS

We first examined the use of outcome variables birth weight and small for gestational age to get insights on modeling practices within the field of maternal asthma. Using directed acyclic graph simulations where gestational age was a potential mediator, we then compared estimated exposure effects in regression models for birth weight, low birth weight, and small for gestational age. Graphs with and without confounding were considered.

RESULTS

Our simulations showed that the variable small for gestational age captures the direct effect of exposure on birth weight, but not the indirect effect of exposure on birth weight through gestational age. Interestingly, exposure effect estimates from small for gestational age models were found unbiased whenever exposure effect estimates from birth weight models were affected by collider bias due to conditioning on gestational age in the models.

CONCLUSIONS

The sole consideration of the outcome small for gestational age in a study may lead to suboptimal understanding and quantification of the underlying effect of an exposure on birth weight-related measures. Instead, our results suggest that both outcome variables (low) birth weight and small for gestational age should minimally be considered in studies investigating perinatal outcomes.

Prenatal exposure to β2-adrenoreceptor agonists and the risk of autism spectrum disorders in offspring

PURPOSE

We aimed to examine the risk of autism spectrum disorders (ASDs) in the offspring who were exposed to maternal use of β2-adrenoreceptor agonist (β2AA) during pregnancy.

METHODS

This is a population-based cohort study including all live singleton births in Denmark from 1 January 1997 to 31 December 2008. Children born to mothers who used β2AA during pregnancy were categorized as exposed, and all other children were included in the unexposed group. Cases of ASDs were identified from the Danish Psychiatric Central Register and the Danish Patient Register. Incidence rate ratio (IRR) and 95% confidence interval were estimated by Poisson regression models.

RESULTS

Among 751 888 children in the cohort, 9098 (1.21%) received a diagnosis of ASDs. We observed an increased risk of ASDs in the exposed children (IRR = 1.28, 1.11-1.47), especially for those who were exposed during the second trimester period (IRR = 1.38, 1.14-1.67). However, when extending the exposure time window to 1 year prior to pregnancy, we observed a similar association in children born to women who received β2AA treatment during pregnancy (IRR = 1.33, 1.11-1.59) to that in children born to women who received β2AA treatment 1 year prior to pregnancy (IRR = 1.35, 1.17-1.56).

CONCLUSION

Our finding suggested that children born to women who used β2AA during pregnancy have an increased risk of ASDs in later life, which is more likely due to underlying maternal diseases rather than the exposure to β2AA itself. However, further study, which would better differentiate the effects between indication and medicine, is needed to corroborate the finding. Copyright © 2017 John Wiley & Sons, Ltd.

In utero Exposure to β-2-Adrenergic Receptor Agonist Drugs and Risk for Autism Spectrum Disorders

OBJECTIVES

The purpose of this study was to investigate associations between use of β-2-adrenergic receptor (B2AR) agonist drugs during pregnancy and risk for autism spectrum disorders (ASD).

METHODS

A case-control study was conducted by using Denmark's health and population registers. Among children born between 1997 and 2006, 5200 cases with ASD admission diagnoses and 52 000 controls without ASD were identified and individually matched on month and year of birth. Conditional logistic regression models were used to estimate odds ratios (OR) and confidence intervals (CI) for any B2AR agonist exposure during pregnancy, preconception, and by trimester.

RESULTS

In total, 3.7% of cases and 2.9% of controls were exposed to B2ARs during pregnancy. Use of B2ARs during pregnancy was associated with increased risk of ASD, even after adjustment for maternal asthma and other covariates (OR: 1.3, 95% CI: 1.1-1.5). The elevated risk was observed with use of B2AR during preconception (OR: 1.3, 95% CI: 1.0-1.6), first trimester (OR: 1.3, 95% CI: 1.1-1.5), second trimester (OR: 1.5, 95% CI: 1.1-1.7), and the third trimester (OR: 1.4, 95% CI: 1.1-1.7). There was some evidence that longer B2AR within-pregnancy use was associated with the increased risk.

CONCLUSIONS

B2AR agonist exposure during pregnancy may be associated with an increased risk for ASD. If the effect is real, any intervention must be balanced against benefits of indicated medication use by pregnant women.

In utero exposure to selective serotonin reuptake inhibitors and risk for autism spectrum disorder

We investigated whether there is an association between increased risk for autism spectrum disorders (ASD) and selective serotonin reuptake inhibitors (SSRIs) used during pregnancy. This study used Denmark's health and population registers to obtain information regarding prescription drugs, ASD diagnosis, and health and socioeconomic status. There were 1.5 % of cases and 0.7 % of controls exposed to SSRIs during the pregnancy period, and higher effect estimates observed with longer use. We found evidence that in utero exposure to SSRIs increases a child's risk associated with ASD. These results, while adding to the limited knowledge on prenatal pharmacological exposures as potential ASD risk factors, need to be balanced against the benefits of indicated medication use by pregnant mothers.

Effect of pregnancy in asthma on health care use and perinatal outcomes

BACKGROUND

It is generally known that pregnancy in asthmatic patients increases the risk of asthma exacerbations and poor perinatal outcomes. However, the effect of pregnancy in asthmatic patients on health care use is not known well. In addition, its effect on perinatal outcomes is still controversial because of study limitations caused by ethical issues. National Health Insurance claim data are an ideal resource for studying real-world health care use patterns of asthma.

OBJECTIVE

We sought to evaluate the effect of pregnancy on asthma in terms of asthma-related health care use and prescription patterns in concert with the effect of asthma exacerbations on adverse pregnancy outcomes.

METHODS

Among all asthmatic patients in the Korean National Health Insurance claim database from January 2009 to December 2013, pregnant women who delivered in 2011 with pre-existing asthma were enrolled. Analyses included asthma-related health care use and prescription patterns compared between pregnant asthmatic women and nonpregnant female asthmatic control subjects, as well as within the pregnant subjects from before pregnancy throughout postpartum periods. In addition, the association between asthma exacerbation during pregnancy and adverse pregnancy outcomes was assessed.

RESULTS

A total of 3,357 pregnant asthmatic patients were compared with 50,355 nonpregnant asthmatic patients, and 10,311 pregnant patients were included to determine the effect of asthma exacerbations on adverse pregnancy outcome in the study. Pregnant asthmatic patients underwent more asthma-related hospitalizations (1.3% vs 0.8%, P = .005) but had significantly fewer outpatient visits and prescriptions for most asthma medications than nonpregnant asthmatic patients. The proportion of patients ever hospitalized gradually increased throughout pregnancy (first trimester, 0.2%; second trimester, 0.5%; and third trimester, 0.7%; P = .018). The prevalence of asthma exacerbation during pregnancy was 5.3%, and the patients who had acute exacerbation during pregnancy had significantly higher asthma-related health care use in terms of hospitalization, intensive care unit admission, and emergency department and outpatient visits within 1 year before delivery than those who had not. However, asthma exacerbation during pregnancy was not significantly related to adverse perinatal outcomes, except for cesarean section (27.1% vs 18.9%, P < .001). All exacerbations were managed with systemic corticosteroids, and the patients who ever experienced acute exacerbations maintained asthma medications, including inhaled corticosteroid-based inhalers, throughout the pregnancy period.

CONCLUSION

Pregnancy profoundly affects asthma-related health care use but to a different degree depending on whether the patient experienced an exacerbation. Asthma exacerbation during pregnancy is not associated with adverse pregnancy outcomes while managed appropriately with systemic corticosteroids. However, further studies are needed to clarify the effect of asthma control on perinatal outcome and delivery method.

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.

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.

Inhaled glucocorticoids during pregnancy and offspring pediatric diseases: a national cohort study

RATIONALE

Glucocorticoid inhalation is the preferred asthma treatment during pregnancy. Previous studies on its safety focused on obstetric outcomes and offspring malformations.

OBJECTIVES

To determine whether glucocorticoid inhalation during pregnancy is a risk factor for offspring pediatric diseases.

METHODS

We studied offspring (live singletons) of pregnant women suffering from asthma during pregnancy (prevalence = 6.3%; n = 4,083 mother-child pairs) from the Danish National Birth Cohort (births, 1996-2002; prospective data). We estimated the associations between use of inhaled glucocorticoids for asthma treatment during pregnancy (n = 1231; 79.9% budesonide, 17.6% fluticasone, 5.4% beclomethasone, and 0.9% other or unspecified glucocorticoids) and offspring diseases (International Classification of Diseases-10th Revision, diagnoses) during childhood. We conducted Cox or logistic regression analyses for each International Classification of Diseases-10th Revision category, controlling for use of non-glucocorticoid-containing inhalants, and confirmed results by addressing confounding by treatment indication using propensity score.

MEASUREMENTS AND MAIN RESULTS

Offspring median age at end of follow-up was 6.1 (range, 3.6-8.9) years. Glucocorticoid inhalation was not associated with offspring disease risk in most categories, except for offspring endocrine, metabolic, and nutritional disorders (hazard ratio, 1.84; 95% confidence interval, 1.13-2.99). When repeating analyses with the major subgroup that used budesonide only, association estimates were of similar magnitude.

CONCLUSIONS

Regarding most disease categories, data are reassuring, supporting the use of inhaled glucocorticoids during pregnancy. In line with animal data, glucocorticoid inhalation during pregnancy may be a risk factor for offspring endocrine and metabolic disturbances, which should be considered further.

Management of asthma in pregnant women by general practitioners: a cross sectional survey

BACKGROUND

Poorly controlled asthma can lead to maternal and fetal complications. Despite the known risks of poorly controlled asthma during pregnancy and the need for stepping up therapy when appropriate, there are concerns that management is suboptimal in primary care.Our objective was to investigate the management of asthma during pregnancy by general practitioners providing shared maternity care.

METHODS

A pre-piloted, anonymous mail survey was sent to all general practitioners (n = 842) involved in shared maternity care at six maternity hospitals in Victoria, Australia. Respondents were asked about their perceived safety of individual asthma medications during pregnancy. Approach to asthma management during pregnancy was further explored using scenarios of pregnant women with stable and deteriorating asthma and poor medication adherence.

RESULTS

Inhaled corticosteroids (ICS) were perceived to be the safest and were the preferred preventive medication in first trimester (74.1%), whilst leukotriene receptor antagonists were the least preferred (2.9%). A quarter (25.8%) of respondents would stop or decrease patients' ICS doses during pregnancy, even when their asthma was well controlled by current therapy. In addition, 12.1% of respondents were not sure how to manage deteriorating asthma during pregnancy and opted to refer to another health professional. Almost half the respondents (48.9%) reported encountering medication nonadherence during pregnancy.

CONCLUSION

A lack of confidence and/or knowledge among general practitioners in managing deteriorating asthma in pregnancy was observed despite a good understanding of the safety of asthma medications during pregnancy, compliance with evidence-based guidelines in the selection of preventive medications, and self reported good asthma knowledge.

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.

Systematic review of the safety of regular preventive asthma medications during pregnancy

OBJECTIVE

To review the safety of regular preventive asthma medications during pregnancy.

DATA SOURCES

The following databases were searched from inception to February 2011: Ovid MEDLINE, PubMed, Cochrane Library, EMBASE and CINAHL Plus.

STUDY SELECTION AND DATA EXTRACTION

The search was limited to human studies published in the English language. Titles of all articles were screened for relevance. Abstracts of relevant articles were scrutinized to confirm relevance before obtaining full text.

DATA SYNTHESIS

Selected articles were read by 2 authors and the accuracy of the data extracted was confirmed.

RESULTS

Thirty-three articles were included in the final review. Small sample size, missing data, inadequate control for confounding factors, and poor documentation of dosage range were common limitations of the studies reviewed. The use of inhaled corticosteroids, cromolyns, and long-acting β(2) agonists during pregnancy was not associated with any particular adverse event, although the fluticasone/salmeterol combination has been associated with poor outcomes in postmarketing studies. Congenital malformations have been reported with leukotriene receptor antagonist exposure during pregnancy, but those women also had exposure to other medications, including oral corticosteroids.

CONCLUSIONS

Some negative outcomes of preventive asthma medications have been reported, although their direct link with medication use is inconclusive. Selection of preventive medications for asthma management during pregnancy should be based on an assessment of the risks and benefits of medication use versus the risks of poorly controlled asthma.

Pregnancy related treatment disparities of acute asthma exacerbations in the emergency department

OBJECTIVE

Asthma is one of the most common medical conditions complicating pregnancy. Despite the presence of published guidelines outlining the care of the pregnant patient with asthma, disparities in the treatment of acute asthma exacerbations in the emergency department related to pregnancy status are known to exist. We sought to determine if pregnancy status affected the treatment of women presenting to a tertiary emergency department for care of acute asthma exacerbations.

METHODS

We retrospectively compared the emergency department treatment of acute asthma exacerbations in 123 pregnant women to 123 non-pregnant controls. Asthma exacerbations were classified by severity according to pre-determined criteria.

RESULTS

In the emergency department (ED), pregnant women were significantly less likely to be treated with systemic corticosteroids than non-pregnant controls (50.8% versus 72.4%, p = 0.001). Similarly, 41% of pregnant women received prescriptions for prednisone at the time of discharge from the ED compared to 69.2% of non-pregnant women (p < 0.001).

CONCLUSIONS

In this population of asthmatics presenting to a tertiary emergency department with acute asthma exacerbations, pregnant women were less likely to receive appropriate therapy with systemic corticosteroids.

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 pregnancy on maternal asthma symptoms and medication use

OBJECTIVE

To examine whether factors related to the patient or her treatment influence asthma severity during pregnancy.

METHODS

Symptom and medication data were collected by in-person and telephone interviews. Women were recruited before 24 weeks of gestation through private obstetricians and hospital clinics. Eight hundred seventy-two women had physician-diagnosed asthma, 686 were active asthmatics, and 641 with complete data were analyzed. The Global Initiative for Asthma measured severity. Cumulative logistic regression models for repeated measures assessed changes in asthma severity during each month of pregnancy.

RESULTS

Two factors had significant and profound effects on the course of asthma: prepregnancy severity and use of medication according to Global Initiative for Asthma guidelines. Although several factors were analyzed (race, age, atopic status, body mass index, parity, fetal sex, and smoking), none were significant risk factors for changes in asthma severity, measured in a clinically important way as a one-step change in Global Initiative for Asthma category. Women with milder asthma received most benefit from appropriate treatment, 62% decreased risk for worsening asthma among those with intermittent asthma (0.38, 95% confidence interval 0.23-0.64) and 52% decreased risk among those with mild persistent asthma (odds ratio 0.48, 95% confidence interval 0.28-0.84). Month or trimester of gestation was not consistently associated with changes in asthma severity.

CONCLUSION

Asthma severity during pregnancy is similar to severity in the year before pregnancy, provided patients continue to use their prescribed medication. If women discontinue medication, even mild asthma is likely to become significantly more severe.

High doses of inhaled corticosteroids during the first trimester of pregnancy and congenital malformations

BACKGROUND

Although reassuring data exist on the use of low-to-moderate doses of inhaled corticosteroids (ICSs) during pregnancy, there are inadequate data for women receiving high doses.

OBJECTIVE

To investigate the association between doses of ICS during the first trimester of pregnancy and the risk of congenital malformations among women with asthma.

METHODS

We conducted a cohort study of 13,280 pregnancies of women with asthma (1990-2002) by linking 3 administrative databases from Quebec (Canada). By using generalized estimation equation models, we compared women taking >0 to 1000 microg/d ICS (beclomethasone dipropionate-chlorofluorocarbone equivalent) with women taking >1000 microg/d and those not taking ICSs. The main outcome measures were all and major congenital malformations.

RESULTS

We identified 1257 infants with a congenital malformation (9.5%) and 782 infants with a major malformation (5.9%). We found that women who used >1000 microg/d ICS (n = 154) were significantly more likely (63%) to have a baby with a malformation than the 4392 women who used >0 to 1000 microg/d (adjusted risk ratio, 1.63; 95% CI, 1.02-2.60). On the other hand, women who used >0 to 1000 microg/d were not found to be more at risk than women who did not use ICSs during the first trimester (n = 8734). Nonsignificant trends of similar magnitude were found for major malformations.

CONCLUSIONS

Our study adds evidence on the safety of low-to-moderate doses of ICS taken during the first trimester but raises concerns about high doses. However, we cannot rule out the possibility of residual confounding by severity in this association.

Inhaled corticosteroids during pregnancy: a review of methodologic issues

BACKGROUND

There is evidence in the literature that inhaled corticosteroids (ICSs) are safe for pregnant women with asthma and their infants. Although this is useful information about ICS use during pregnancy, some articles must be viewed cautiously because of lack of power and adjustment for potentially important confounding variables.

OBJECTIVE

To summarize evidence on the potential effects of ICSs to treat asthma in pregnant mothers and their children with particular focus on study power.

METHODS

Studies published before September 1, 2007, and focusing mainly on ICS use for asthma treatment during pregnancy were researched in Pubmed and the Cochrane Library. Post hoc power calculations were completed using data reported in the published articles.

RESULTS

Twenty-three studies that evaluated the associations between ICS use during pregnancy and maternal and/or perinatal outcomes were retained. Only six studies on the association between ICS use and maternal outcomes reported significant results; five studies found significant associations between ICS use and perinatal outcomes. Regarding non-significant results, two studies on maternal outcomes and seven studies on perinatal outcomes had a power higher than 80% to detect a relative risk of 1.5 or a mean birth weight difference of 500 g.

CONCLUSION

While there currently is some degree of evidence to support the safety of ICS use during pregnancy, this review highlights the limited statistical power of several studies published in this area.

Pregnancy outcomes in women using inhaled fluticasone during pregnancy: a case series

BACKGROUND

The aim of the study was to report the maternal and fetal outcomes of women with respiratory illnesses who were treated with inhaled fluticasone during pregnancy.

MATERIAL AND METHODS

We identified 12 cases treated with inhaled fluticasone during pregnancy out of women who received obstetric and teratogen-risk evaluation at the Korean Motherisk Program. A detailed medical and obstetric history was obtained and cases were followed-up until either spontaneous or voluntary pregnancy termination or delivery occurred.

RESULTS

None of the participants had any obstetric complication. However, in addition to fluticasone, most of the 12 cases were simultaneously exposed to a variety of medications. There were 3 abortions (one spontaneous and 2 requested by the patients arguing personal reasons). Live born babies without any evidence of major congenital malformations included 8 singleton babies and 2 twins. Of them, 3 babies were born prematurely.

CONCLUSIONS

Our results are in agreement with previous large studies where no increased rate of adverse outcomes was reported with the use of inhaled corticosteroids during pregnancy.

Effect of maternal asthma and asthma control on pregnancy and perinatal outcomes

BACKGROUND

Asthma is a common condition during pregnancy.

OBJECTIVE

We sought to determine the effect of asthma on the rates of adverse pregnancy and fetal outcomes.

METHODS

We identified pregnancies among black and white women age 15 to 44 with singleton gestations enrolled in the Tennessee Medicaid program over a period of 9 consecutive years, from 1995to 2003, and used claims data to determine the relationship of maternal asthma and asthma exacerbations on pregnancy and infant outcomes.

RESULTS

Among the 140,299 pregnancies, 6.5% were in women with asthma. Among women with asthma, 23% had a hospital or emergency department visit (exacerbated asthma); 40% of black and 23% of white women received hospital or emergency department care for asthma during pregnancy. After controlling for race and other covariates, birth weights among infants of women with asthma were, on average, 38 g lower, and among infants of women with exacerbated asthma they were, on average, 56 g lower. There were moderate, dose-dependent relationships between asthma alone and exacerbated asthma with hypertensive disorders of pregnancy, membrane-related disorders, preterm labor, antepartum hemorrhage, and cesarean delivery. Maternal asthma was not associated with preterm birth or birth defects.

CONCLUSION

Asthma is a risk factor for several common adverse outcomes of pregnancy, and poorly controlled asthma during pregnancy increases these risks.

CLINICAL IMPLICATIONS

It is possible that both maternal and infant outcomes could be improved in this population with appropriate asthma care, especially among black women.

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.

Human Teratogens and Evidence-based Teratogen Risk Counseling: The Motherisk Approach

There are only a limited number of drugs proven to be human teratogens including thalidomide, isotretinoin, coumarin derivates, valproic acid, and folate antagonists. In some cases, the combination of 2 drugs may increase the teratogenic risk. The risk of birth defects may also vary with the time at which the drug is administered during pregnancy and the dose. There are some examples of drugs in which the dose has proven to be a major determinant of their teratogenicity in humans. There is more safety information for older than for newer drugs. Proactive teratogen risk counseling should include a critical appraisal of all available data including the consequences of the untreated maternal condition.

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.

Use of anti-asthmatic drugs during pregnancy. 2. Infant characteristics excluding congenital malformations

OBJECTIVE

To study the characteristics of the infants born to women who have used anti-asthmatic drugs during pregnancy.

MATERIAL AND METHODS

Various characteristics of infants with mothers who had reported the use of anti-asthmatic drugs in early pregnancy (n=24,750) or had such drugs prescribed later during pregnancy by a maternity health care centre (n=763) were identified from the Swedish Medical Birth Register and compared to those of all infants. Risks estimated with Mantel-Haenszel technique were expressed as odds ratios (OR) with 95% confidence intervals after adjustment for a number of putative confounders. The severity of maternal asthma was assessed on the basis of the number of anti-asthmatic drugs used.

RESULTS

An increased risk for preterm birth, low birth weight and small for gestational age was found, which increased with the number of anti-asthmatic drugs used by the mother during pregnancy (OR=1.46, 1.67, and 1.70, respectively, when three or more drugs had been used). An increased risk for large for gestational age could be explained by the effect of gestational diabetes and high body mass index. An increased risk for neonatal icterus was mainly an effect of preterm birth, while an increased risk for respiratory problems and/or low Apgar score (OR=1.43) was only slightly reduced in full-term infants. An increased risk for hyperglycaemia (OR=1.62) was not explained by confounding from maternal diabetes. No risk increase was found for neonatal convulsions or cerebral haemorrhage. Mortality was increased only among infants whose mother had used three or more anti-asthmatic drugs (OR=1.52).

CONCLUSION

Infants whose mothers had asthma had a number of manifestations of poor outcome which appeared to be linked with the severity of the asthma.

Maternal vaccination and preterm birth: using data mining as a screening tool

OBJECTIVE

The main purpose of this study was to identify possible associations between medicines used in pregnancy and preterm deliveries using data mining as a screening tool.

SETTINGS

Prospective cohort study.

METHODS

We used data mining to identify possible correlates between preterm delivery and medicines used by 92,235 pregnant Danish women who took part in the Danish National Birth Cohort (DNBC). We then evaluated the association between one of the identified exposures (vaccination) and the risk for preterm birth by using logistic regression. The women were classified into groups according to their exposure to vaccination. The regression analyses were adjusted for the following covariates: parity, infant's gender, maternal Body-Mass Index (BMI), age, smoking, drinking, job, number of inhabitants in the place of residence, infections, diabetes, high blood pressure and preeclampsia.

MAIN OUTCOME MEASURE

Preterm birth, a delivery occurring before the 259th day of gestation (i.e., less than 37 full weeks).

RESULTS

Data mining had indicated that maternal vaccination (among other factors) might be related to preterm birth. The following regression analysis showed that, the women who reported being vaccinated shortly before or during gestation had a slightly higher risk of giving preterm birth (O.R. = 1.14; 95% CI 1.04-1.25) as compared to the non-vaccinated group.

CONCLUSION

Whether the association between maternal vaccination and the risk for preterm birth found here is causal or not deserves further studies. Data mining, especially with additional refinements, may be a valuable and very efficient tool to screen large databases for relevant information which can be used in clinical and public health research.

Asthma and pregnancy

Asthma complicates 4-8% of pregnancies. Mild and well-controlled moderate asthma can be associated with excellent maternal and perinatal pregnancy outcomes. Severe and poorly controlled asthma may be associated with increased prematurity, need for cesarean delivery, preeclampsia, growth restriction, other perinatal complications, as well as maternal morbidity and mortality. Optimal management of asthma during pregnancy includes objective monitoring of lung function, avoiding or controlling asthma triggers, patient education, and individualized pharmacologic therapy. Those with persistent asthma should be monitored by peak expiratory flow rate, spirometry to measure the forced expiratory volume in 1 second, or both. Step-care therapeutic approach uses the least amount of drug intervention necessary to control a patient's severity of asthma. Inhaled corticosteroids are the preferred treatment for the management of all levels of persistent asthma during pregnancy. It is safer for pregnant women with asthma to be treated with asthma medications than it is for them to have asthma symptoms and exacerbations. The ultimate goal of asthma therapy is maintaining adequate oxygenation of the fetus by prevention of hypoxic episodes in the mother. Asthma exacerbations should be aggressively managed, with a goal of alleviating asthma symptoms and attaining peak expiratory flow rate or forced expiratory volume in 1 second of 70% predicted or more. Pregnancies complicated by moderate or severe asthma may benefit from ultrasound for fetal growth and accurate dating and antenatal assessment of fetal well-being. Asthma medications should be continued during labor, and parturients should be encouraged to breastfeed.

Is fetal gender associated with emergency department visits for asthma during pregnancy?

BACKGROUND

To investigate if fetal gender (1) affects the risk of having an emergency department (ED) visit for asthma; and (2) is associated with adverse pregnancy outcomes among women who had at least one visit to the ED for asthma during pregnancy.

METHODS

We linked two provincial administrative databases containing records on in-patient deliveries and ED visits. The study sample included women who delivered a live singleton baby between April 2003 and March 2004. Pregnant women who made at least one ED visit for asthma were counted as cases and the rest of the women as control subjects. We performed a multivariable analysis using logistic regression to model the risk of having an ED visit for asthma, with fetal gender being one of the predictors. In addition, a series of multivariable logistic regressions were also constructed separately for cases and controls for the following adverse delivery outcomes: low birth weight baby, preterm delivery, and delivery via Caesarian section.

RESULTS

Among 109,173 live singleton deliveries, 530 women had visited ED due to asthma during pregnancy. While having an ED visit for asthma was positively associated with teenage pregnancy, low income, and presence of pregnancy-induced hypertension, it was not associated with fetal gender (OR 1.01, 95% CI 0.85-1.19). Fetal gender was not a significant predictor of adverse pregnancy outcomes among women who had an asthma ED visit during pregnancy.

CONCLUSION

Fetal gender does not affect the risk of having an ED visit for asthma during pregnancy, and it is not associated with adverse pregnancy outcomes among women who had an asthma-related ED during pregnancy.

Cessation of asthma medication in early pregnancy

OBJECTIVE

The objective of the study was to determine whether women alter their use of asthma medications during pregnancy.

STUDY DESIGN

Weekly asthma medication use was determined from prescription claims data in a cohort of 112,171 pregnant women aged 15 to 44 years who were continuously enrolled in the Tennessee Medicaid program prior to their singleton pregnancy and who delivered a singleton birth during 1995 to 2001. Change in asthma medication use was evaluated using generalized estimating equation analyses.

RESULTS

Women with asthma significantly (P < or = 0.0005) decreased their asthma medication use from 5 to 13 weeks of pregnancy. During the first trimester, there was a 23% decline in inhaled corticosteroid prescriptions, a 13% decline in short-acting beta-agonist prescriptions, and a 54% decline in rescue corticosteroid prescriptions.

CONCLUSIONS

Utilization of all categories of asthma medications decreased in early pregnancy, with the largest declines occurring for inhaled and rescue corticosteroids.

Associations between socio-economic factors and the use of prescription medication during pregnancy: a population-based study among 19,874 Danish women

OBJECTIVE

To examine the association between socio-economic factors and use of prescription medication during pregnancy in a population of Danish women.

METHODS

This was a population-based cohort study. Using record linkage from public administrative registries, we described the use of prescription medication during pregnancy and the financial and educational resources for each pregnant woman in the cohort.

RESULTS

The analyses included all 19,874 primiparous women delivering singletons in North Jutland county, Denmark, in 1991-1998. We identified 24,243 prescriptions filled by the women during their pregnancies. The highest overall prescription medication use was among women with basic schooling (OR 1.3; 95% CI 1.2-1.4), and lowest among women with the highest education (OR: 0.8; 95% CI 0.7-0.9) compared with women who had vocational education. Stratified analysis of therapeutic subgroups revealed that socio-economic factors were associated with the use of anti-infective and anti-asthmatic medications during pregnancy.

CONCLUSION

Maternal educational level, and to a lesser degree household income, paternal educational level and cohabitation status, was associated with the use of prescription medication during pregnancy. However, the analyses did not take into account important clinical variables such as maternal illness, and the results could be affected by differential misclassification of exposure information, by confounding or chance.

Outcomes of pregnancy in asthmatic women

Mild and moderate asthma can be associated with excellent maternal and perinatal pregnancy outcomes, especially if patients are managed according to contemporary NAEPP recommendations. Severe and poorly controlled asthma may be associated with increased mild prematurity (<37 weeks' gestation), a need for cesarean delivery, preeclampsia, and growth restriction. Poorly controlled asthma and severe asthma exacerbations can result in maternal morbidity and mortality, which can have commensurate adverse pregnancy outcomes.

Association between bronchial asthma in pregnancy and shorter gestational age in a population-based study

OBJECTIVE

To study the association between bronchial asthma during pregnancy and gestational age/birth weight, and also preterm birth and low birth weight.

METHOD

In the population-based large data set of the Hungarian Case-Control Surveillance System of Congenital Abnormalities, 1980-1996, controls without congenital abnormalities were analysed.

RESULTS

Of 38,151 newborn infants, 757 (2.0%) had mothers with bronchial asthma during pregnancy, 88% were medically recorded prospectively. Mothers with bronchial asthma in pregnancy had 0.6 week shorter gestational age and a higher proportion of preterm births (14.1% vs. 9.1%). These findings were reflected with a lower mean birth weight (3,102 vs. 3,279 gram) and higher proportion of low birth weight newborns (9.0% vs. 5.6%).

CONCLUSION

The old fashioned anti-asthmatic drugs were not able to prevent the bronchial asthma-related preterm birth, thus there is an urgent need to use modern inhaled therapies.

Methodological issues in the epidemiological study of the teratogenicity of drugs

The review presented here discusses and exemplifies problems in epidemiological studies of drug teratogenesis according to methodology: case-control studies, cohort studies, or total population studies. Sources of errors and the possibility of confounding are underlined. The review stresses the caution with which conclusions have to be drawn when exposure data are retrospective or other possible bias exists. It also stresses the problem with the multiple testing situation that is usually present in the studies. It is therefore difficult to draw any firm conclusion from single studies and still more difficult to draw conclusions on causality. As randomized studies are in most cases out of the question, one has to rely on the type of studies which can be made, but the interpretation of the results should be cautious. The ideal study, next to a randomized one, is a large prospective study with detailed exposure information and detailed and unbiased outcome data. Even so, such a study can mainly be used for identifying possible associations which have to be verified or rejected in new studies. Nearly every finding of a risk increase, if not extremely strong, should only be regarded as a tentative signal to be tested in independent studies.

Using the ecology model to describe the impact of asthma on patterns of health care

BACKGROUND

Asthma changes both the volume and patterns of healthcare of affected people. Most studies of asthma health care utilization have been done in selected insured populations or in a single site such as the emergency department. Asthma is an ambulatory sensitive care condition making it important to understand the relationship between care in all sites across the health service spectrum. Asthma is also more common in people with fewer economic resources making it important to include people across all types of insurance and no insurance categories. The ecology of medical care model may provide a useful framework to describe the use of health services in people with asthma compared to those without asthma and identify subgroups with apparent gaps in care.

METHODS

This is a case-control study using the 1999 U.S. Medical Expenditure Panel Survey. Cases are school-aged children (6 to 17 years) and young adults (18 to 44 years) with self-reported asthma. Controls are from the same age groups who have no self-reported asthma. Descriptive analyses and risk ratios are placed within the ecology of medical care model and used to describe and compare the healthcare contact of cases and controls across multiple settings.

RESULTS

In 1999, the presence of asthma significantly increased the likelihood of an ambulatory care visit by 20 to 30% and more than doubled the likelihood of making one or more visits to the emergency department (ED). Yet, 18.8% of children and 14.5% of adults with asthma (over a million Americans) had no ambulatory care visits for asthma. About one in 20 to 35 people with asthma (5.2% of children and 3.6% of adults) were seen in the ED or hospital but had no prior or follow-up ambulatory care visits. These Americans were more likely to be uninsured, have no usual source of care and live in metropolitan areas.

CONCLUSION

The ecology model confirmed that having asthma changes the likelihood and pattern of care for Americans. More importantly, the ecology model identified a subgroup with asthma who sought only emergent or hospital services.

Acute asthma in pregnancy

Asthma is one of the most common medical conditions that can complicate pregnancy. Although most pregnant women with asthma have controlled disease, some women may experience exacerbation of their disease, necessitating immediate intervention. This article discusses the interrelations between asthma and pregnancy and presents an overview on the management of pregnant women presenting to the hospital with acute severe asthma. Treating physicians must overcome the common belief that pregnant women should not take any medications during pregnancy, and they should keep asthma in pregnant women under control to minimize the risk for maternal and fetal hypoxia.

Risk factors for low birth weight: a review

Low birth weight (LBW) is one of the main predictors of infant mortality. The global incidence of LBW is around 17%, although estimates vary from 19% in the developing countries (countries where it is an important public health problem) to 5-7% in the developed countries. The incidence in Spain in the decade 1980-1989 was about 5.7%. LBW is generally associated with situations in which uterine malnutrition is produced due to alterations in placental circulation. There are many known risk factors, the most important of which are socio-economic factors, medical risks before or during gestation and maternal lifestyles. However, although interventions exist to prevent many of these factors before and during pregnancy, the incidence of LBW has not decreased.

Can We Ensure the Safe Use of Known Human Teratogens?

The prescription of known teratogenic medications requires a careful balance between allowing women access to medications that they might need and avoiding unnecessary exposure to these medications during pregnancy because of their devastating fetal effects. Isotretinoin, a potent human teratogen, is of particular concern because of its widespread use among reproductive-aged women and the dramatic increase in use from 1992 through 2000. A revised risk management system was implemented in 2002 because of concerns about the continued occurrence of isotretinoin-exposed pregnancies. However, the recent approval of three generic versions of isotretinoin in the US has further complicated risk management and raises concerns that use might increase further if the lower cost of generics serves to increase accessibility. There are now four separate isotretinoin risk management systems in the US, each with its own distinct packaging, though the requirements for and substance of each are identical. Some additional concrete steps could be taken to minimise any unnecessary use of isotretinoin and help allow an adequate assessment of the current risk management systems. In addition to being familiar with and following all aspects of the current risk management system, physicians could choose to limit the use of isotretinoin to those who meet the labelled indications in order to reduce the number of exposed pregnancies. All four companies currently marketing isotretinoin in the US could jointly and voluntarily establish a consolidated, mandatory registration and follow-up of all women of reproductive potential who receive an isotretinoin prescription. Mandatory registration has many challenges, but it could allow a clear accounting of the total number of women for whom follow-up information is and is not available. Although the companies cannot be legally compelled to use a consolidated approach, the use of a single registry for the originator's product and all generic brands would allow identification of duplicates and also avoid the confusion that is introduced by providing materials that not only look different, but also have different addresses, contact information and names for participation in follow-up surveys. This is particularly important because women might take more than one version of isotretinoin during a single course of therapy or might receive a different programme's materials from their doctor than from the pharmacy. Though the introduction of generic versions of isotretinoin further complicates risk management, the companies marketing isotretinoin have an opportunity to work together to demonstrate their commitment to both limit the occurrence of exposed pregnancies and conduct a meaningful evaluation of the occurrence of pregnancies exposed to isotretinoin.