Pregnancy outcome of asthmatic patients: a population-based study

Non-allergic factors that influence asthma control in pregnancy

INTRODUCTION

Numerous factors may influence the asthma course during pregnancy, potentially elevating the risk of specific pregnancy complications. This study aimed to evaluate non-allergic factors influencing asthma and to assess perinatal outcomes between asthmatic and non-asthmatic pregnancies in the population of the Pomeranian Voivodeship region of Poland.

METHODS

The mixed cohort study was performed with 83 pregnant asthmatic patients aged 18-38 years. The control group consisted of 83 patients without asthma diagnosis or symptoms. A specially designed questionnaire was used to evaluate asthma course and perinatal outcomes. An Asthma Control Test (ACT) adapted for pregnancy was performed on enrollment. Asthma severity was assessed according to GINA guidelines.

RESULTS

In 19 cases (22.80%), patients quit their regular treatment after pregnancy was confirmed. Respiratory tract infection occurred in 23 patients (27.71%) and had been statistically significantly more frequent among patients with partially and uncontrolled asthma (χ2=8.504, p<0.05). No statistically significant difference was found between infection episodes and perinatal complications. The incidence of cesarean section was significantly higher among patients with asthma (χ2=16.37, p<0.01), particularly in patients with severe asthma (χ2=7.07, p<0.05) and uncontrolled asthma (χ2=6.7, p<0.05). Apgar score was statistically significantly lower in patients with severe asthma (χ2=20.37, p<0.05).

CONCLUSIONS

Respiratory tract infections and adequate asthma treatment are the most important modifiable factors in preventing perinatal complications associated with asthma.

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.

The influence of asthma on neuroinflammation and neurodevelopment: From epidemiology to basic models

Asthma is a highly heterogeneous inflammatory disease that can have a significant effect on both the respiratory system and central nervous system. Population based studies and animal models have found asthma to be comorbid with a number of neurological conditions, including depression, anxiety, and neurodevelopmental disorders. In addition, maternal asthma during pregnancy has been associated with neurodevelopmental disorders in the offspring, such as autism spectrum disorders and attention deficit hyperactivity disorder. In this article, we review the most current epidemiological studies of asthma that identify links to neurological conditions, both as it relates to individuals that suffer from asthma and the impacts asthma during pregnancy may have on offspring neurodevelopment. We also discuss the relevant animal models investigating these links, address the gaps in knowledge, and explore the potential future directions in this field.

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

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

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

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

Аllergic Basal Deciduitis as a Reason of Recurrent Antenatal Fetal Death

BACKGROUND: Allergic diseases of pregnant women are associated with chronic placental insufficiency and the development of immunopathological conditions of unknown etiology in a child in postnatal life. Pregnancy with bronchial asthma is often complicated by intrauterine growth retardation, preeclampsia, and antenatal fetal death. AIM: The objective was to present a clinical case of recurrent antenatal fetal death in the third trimester in women with bronchial asthma under controlled course. CASE REPORT: Pregnancy proceeded without clinical signs of exacerbation of bronchial asthma and allergic status. However, chronic inflammation with eosinophilia in the intervillous space and the basal lamina was revealed in the placenta tissue. Eosinophilia of the intervillous area was accompanied by obliteration of the intervillous area by fibrin deposits. CONCLUSION: We suppose that immunological inflammation at the fetoplacental unit level can occur regardless of the mother’s allergic status. Moreover, it is likely that the objective state of the mother in the presence of an allergic disease does not reflect the presence/absence of an immunological process in the placenta, as the immunological inflammatory process can develop in different compartments (at the level of the mother’s body and the placental-fetal compartment) with varying degrees of severity.

Impact of allergic diseases on fertility

The incidence of allergic diseases has been increasing in recent decades, and currently, nearly 30% of the European population suffer from some type of allergy. Also, an increasing number of people are suffering from infertility. Both diseases are related to the hormonal and immune systems, which prompts the question as to whether there is a causal relationship between allergic disorders and the reproductive system. The purpose of this review is to evaluate whether there is a link between allergic diseases and infertility, using the available literature.

Female asthma and atopy - impact on fertility: a systematic review

Background and objective

Asthma is one of the most common chronic diseases among women of reproductive age, and previous studies have suggested a link between female asthma and infertility. The aim of the present review is to provide an update on current knowledge of the association between female asthma and/or atopy and a reduction in fertility, ie, number of offspring, time to pregnancy (TTP) and need for fertility treatment.

Methods

Systematic review performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses-guidelines.

Results

A total of 14 studies fulfilled the predefined criteria for inclusion in the present review. Six studies investigated the association between female asthma and/or atopy and number of offspring, of which one reported a positive, two a negative, and three no association. Three studies addressed the association between asthma and TTP and found that TTP was significantly prolonged in asthmatic women compared to non-asthmatic women. Five studies investigated subfertility and the need for fertility treatments of which two studies found a higher prevalence of infertility among women prescribed anti-asthma medication. One study found no difference in the number of fertility treatments of asthmatic women compared to non-asthmatic women, whereas three studies reported that female asthma was associated with significantly more fertility treatment compared to non-asthmatic women.

Conclusion

Although the available evidence is conflicting, there is a clear trend toward an association between female asthma and a reduction in fertility, and by that a larger proportion requiring fertility treatment, even though female asthma might not negatively affect total number of offspring.

Prospective cohort study of pregnancy complications and birth outcomes in women with asthma

Background

Asthma is the most common potentially serious medical complication in pregnancy. The purpose of this study was to determine the association between maternal asthma and a spectrum of adverse neonatal and maternal outcomes.

Methods

Events during pregnancy and birth outcome were evaluated in 34 asthmatic as well as 1569 non-asthmatic pregnant women who were enrolled in a prospective cohort study undertaken at the antenatal clinics of Mobini Hospital in Iran. The women were interviewed and classified according to clinical severity and asthma control as per GINA guidelines. Information on asthma symptoms was collected by a questionnaire as well as by spirometry and physical examination. All subjects were followed until delivery, and postpartum charts were reviewed to assess neonatal and maternal outcomes. Eosinophil cells counts were obtained and total IgE was measured by ELISA. Results were assessed by multivariate logistic regression adjusting for maternal age and parity, and for birth outcomes, for gestational diabetes, and hypertension/pre-eclampsia.

Results

The well-known relationship between family history of asthma and asthma in pregnancy was again supported (p < 0.001). Women with asthma had more bleeding events 3 weeks or more before delivery (OR 3.30, 95% CI 1.41–7.26), more often placenta problems (OR 6.86, 95% CI 1.42–33.02), and gestational diabetes mellitus (OR 3.82, 95% CI 1.06–13.75). No significant differences between asthmatic and non-asthmatic mothers regarding duration of gestation, birthweight, low Apgar scores, or neonatal respiratory difficulties were found. Total IgE antibody levels and eosinophil counts did not differ by asthma control and severity.

Conclusions

Asthma in pregnancy poses some risk for pregnancy complications and adverse perinatal outcomes. Managing asthma effectively throughout pregnancy could benefit women and their babies and help to reduce the health burden associated with asthma during pregnancy.

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.

Maternal asthma: pregnancy course and outcome

OBJECTIVE

To evaluate the association between maternal asthma and perinatal outcome.

STUDY DESIGN

In this retrospective population-based cohort study, all pregnancies between 1991 and 2014 in a tertiary medical center, were included. Multiple pregnancies and congenital malformations were excluded. Pregnancy course and outcomes were compared between women with and without asthma, and multivariable generalized estimating equations were used to control for confounders.

RESULTS

During the study period, 243,363 deliveries met the inclusion criteria, 1.35% of which (n = 3283) occurred in women diagnosed with asthma. Multiple perinatal complications were found to be associated with maternal asthma, including hypertensive disorders, preterm delivery, and cesarean delivery. However, no significant differences between the groups were noted in neonatal outcomes, including perinatal mortality rates and low Apgar scores. In the regression model, maternal asthma was noted as an independent risk factor for preterm delivery, hypertensive disorders of pregnancy, and cesarean delivery (aOR = 1.21, 95%CI 1.1-1.4, p = .007; aOR = 1.35, 95%CI 1.2-1.6, p < .001; and aOR = 1.27, 95%CI 1.2-1.4, p < .001, respectively) while controlling for multiple confounders.

CONCLUSIONS

Maternal asthma is associated with an increased risk for adverse pregnancy outcome. This association remains significant while controlling for variables considered to coexist with maternal asthma. Nevertheless, perinatal outcome is generally favorable.

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

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

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

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

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Xolair Pregnancy Registry (EXPECT): the safety of omalizumab use during pregnancy

BACKGROUND

For many asthma medications, pregnancy safety data remains insufficient.

OBJECTIVE

The omalizumab pregnancy registry, EXPECT, evaluates maternal, pregnancy, and infant outcomes after exposure to omalizumab, including incidence of congenital anomalies.

METHODS

EXPECT is a prospective, observational study of pregnant women exposed to ≥1 dose of omalizumab within 8 weeks prior to conception or at any time during pregnancy. Primary outcome measures include rates of live births, elective terminations, stillbirths, and congenital anomalies. Data were collected at enrollment, each trimester, birth, and every 6 months up to 18 months post-delivery.

RESULTS

As of November 2012, 188 of 191 pregnant women were exposed to omalizumab during their first trimester. Of 169 pregnancies with known outcomes (median exposure during pregnancy, 8.8 months), there were 156 live births of 160 infants (4 twin pairs), 1 fetal death/stillbirth, 11 spontaneous abortions, and 1 elective termination. Among 152 singleton infants, 22 (14.5%) were born prematurely. Of 147 singleton infants with weight data, 16 (10.9%) were small for gestational age. Among 125 singleton full-term infants, 4 (3.2%) had low birth weights. Overall, 20 infants had congenital anomalies confirmed, 7 (4.4%) of whom had 1 major defect. No pattern of anomalies was observed.

CONCLUSIONS

To date, proportions of major congenital anomalies, prematurity, low birth weight, and small size for gestational age observed in the EXPECT registry are not inconsistent with findings from other studies in this asthma population. Recognizing the small sample size available, no apparent increased birth prevalence of major anomalies or patterns of major anomalies has been observed.

Female asthma has a negative effect on fertility: what is the connection?

Reproductive changes such as impaired fertility and adverse pregnancy outcomes have been related to female asthma. We recently found that time to pregnancy is prolonged in asthmatic females especially in women with moderate to severe asthma and in those above 30 years of age. Despite their reproductive difficulties the asthmatics ultimately conceived just as many biological children as healthy throughout their reproductive lives. This knowledge therefore raises questions about how asthma affects fertility pathophysiologically. The purpose of this review is to describe the existing knowledge in this field and suggest hypotheses of causal relationships, which may form the basis for future studies in this field. The aim is, in particular, in the literature to examine whether there is any evidence to suggest that the systemic inflammation that characterizes asthma, can affect fertility. The issue is potentially clinically important for asthmatic, infertile individuals and society because treatment of the general systemic inflammation associated with the asthmatic disease combined with hormone stimulation might be the optimal target for an effective infertility therapy, possibly decreasing the need for in vitro fertilization.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Smoking and respiratory conditions in pregnancy: associations with adverse pregnancy outcomes

OBJECTIVES

Acute and chronic respiratory conditions affect a large segment of pregnant women. The purpose of the current study was to examine the concomitant effects of respiratory conditions and smoking during pregnancy on gestational age, birth weight, fetal distress, infant mortality, premature rupture of membranes, placenta abruption, and mode of delivery.

METHODS

This study used data (n = 1,064,969) from the North Carolina linked birth/infant death files from 1999 to 2007. Logistic regression was used to compute odds ratios and 95% confidence intervals (CIs) in assessing risk of adverse pregnancy outcomes.

RESULTS

We found that women with respiratory conditions/smoking status were significantly more likely than nonsmokers with no respiratory conditions to have a low-birth-weight infant, an infant with fetal distress, and experience preterm birth and an infant's death. Adjusted odds ratios also revealed that smokers with respiratory conditions were 2.37 (95% CI 1.69-3.32) times more likely than women with no respiratory conditions/nonsmoking status to have placenta abruption and 2.20 (95% CI 1.85-2.61) times more likely to have premature rupture of membranes. Regardless of smoking status, women with respiratory conditions were less likely to have a vaginal delivery.

CONCLUSIONS

These findings underscore the need for clinical and public health programs to educate women, particularly those with respiratory diseases, of the immense array of adverse outcomes that may occur as a consequence of active maternal smoking during gestation. It is important for interventions to target mothers with respiratory conditions early on to ensure favorable birth outcomes.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Common respiratory issues in ambulatory obstetrics

This article reviews the diagnosis and management of the most common respiratory conditions complicating pregnancy--asthma and influenza. We also review strategies for smoking cessation in pregnancy as, in addition to exacerbating all other pulmonary conditions, smoking is the most modifiable risk factor for poor pregnancy outcome. Moreover, the obstetrician frequently encounters each of these conditions in the ambulatory setting. A thorough knowledge of the normal pregnancy-induced physiological respiratory changes combined with a comprehensive understanding of how to manage these conditions, will provide the obstetrician with the armamentarium needed to optimize health outcomes for mothers and their fetuses.

Perinatal complications associated with maternal asthma during pregnancy

BACKGROUND

Asthma is one of the most common medical illnesses occurring in pregnancy and its incidence amongst the obstetric population is increasing. Previous studies have suggested that asthma is not a benign illness in pregnancy, and can contribute towards increased rates of pregnancy complications.

METHODS

We undertook a retrospective audit of 6458 deliveries during 2008 at The Royal Women's Hospital to determine the perinatal outcomes for women with a self-reported diagnosis of asthma.

RESULTS

We found that 501 (7.8%) deliveries were to women who identified themselves as asthmatics. Of these, 15.6% reported exacerbations of their asthma symptoms during pregnancy, with the remainder reporting improvement or stabilization. There was an increased rate of preterm birth (12.9%) in the asthmatic population, compared to the non-asthmatic population (OR = 1.48, CI [1.12-1.95], P = 0.005). Asthma remained significantly associated with an increased risk of preterm birth after adjusting for maternal smoking status using logistic regression analysis (Adjusted OR 1.41, CI [1.07-1.86], P = 0.01). Women were also at increased risk of developing pre-eclampsia (OR 1.71, CI [1.09-2.67], P = 0.02) but not fetal growth restriction. Women identifying themselves as asthmatics were also more likely to deliver by caesarean section (OR 1.32, CI [1.09-1.6], P = 0.003).

CONCLUSION

These findings suggest that maternal asthma may be associated with an increased risk of preterm birth, pre-eclampsia and caesarean delivery.

Maternal asthma medication use and the risk of selected birth defects

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Asthma and rhinitis during pregnancy

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

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

BACKGROUND

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

OBJECTIVE

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHOR'S CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Asthma in pregnancy

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.

Asthma and pregnancy: repercussions for neonates

OBJECTIVE

To describe socioeconomic and behavioral aspects of pregnant women with asthma and to analyze the effects of maternal asthma on certain perinatal parameters in a birth cohort.

METHODS

An observational crosssectional analytical study using data regarding the mothers of a birth cohort at maternity hospitals in the greater metropolitan area of Aracaju, Brazil, between the 8th of March and the 15th of July of 2005. In the pregnant women, asthma was self-reported, based on previous medical diagnosis. Epidemiological, obstetric and perinatal variables were studied.

RESULTS

Of the 4,757 mothers included in the study, 299 (6.3%) had asthma. The mothers with asthma had lower family incomes and more frequently made use of the public health care system (for prenatal care and delivery) than did those without asthma. Although only 9.4% of the mothers with asthma smoked and only 27.6% consumed alcoholic beverages, these proportions were higher than were those observed for the control group. Asthma was not found to be associated with obstetric problems or with problems involving the neonates. Nor did we find asthma to be associated with cesarean delivery, prematurity or small-for-gestational-age neonates.

CONCLUSIONS

Low socioeconomic level seems to be a risk factor for asthma.

Frequency of asthma as the cause of dyspnea in pregnancy

OBJECTIVE

To estimate the prevalence of asthma among pregnant women with dyspnea.

METHODS

Pregnant women referred for prenatal care visits who had complaints of dyspnea were included. All pregnant women were evaluated by a respiratory specialist. Spirometry was performed by a single trained physician.

RESULTS

Asthma was diagnosed in 38.8% of participants. Dyspnea was diagnosed as being physiologic in 36.4% of cases, but 24.8% of cases were of probable asthma (spirometric values were within normal range but symptoms and signs were suggestive of asthma). Cough, wheezing, and post-exercise symptoms were significantly more prevalent in asthmatic and probable-asthmatic women than in women without asthma.

CONCLUSION

Dyspnea in pregnancy can be physiologic, but when it is accompanied by other symptoms such as cough or wheezing it is likely to be caused by asthma. Because of the high prevalence of asthma during pregnancy, it seems logical to evaluate dyspnea via physical examination and response to bronchodilators.

Asthma and pregnancy: a review of two decades

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

The occurrence of asthma in hospitalized patients with type 2 diabetes mellitus

Diabetes mellitus (DM) has been found to be associated with cardiovascular disease. The goal of this study is to evaluate the prevalence of asthma in patients with type II DM after adjusting for other comorbid conditions. We used patient treatment files of inpatients' admissions containing discharge diagnosis (Classification of Mental and Behavioural Disorders (ICD)-9 codes) from Veterans Health Administration Hospitals. The patients were divided into two groups: ICD-9 code for DM and a control group with hypertension but no DM. ICD-9 codes for asthma were used to study the prevalence of asthma in DM patients versus the control. We performed uni- and multi-variable analysis adjusting for comorbid conditions. Asthma was present in 13 242 (4.5%) of DM patients versus 16 038 (2.9%) in the control group. Using multi-variable analysis, DM remained independently associated with asthma (odds ratio: 2.99; confidence interval: 2.92-3.06; P < 0.0001). The prevalence of asthma is significantly higher in hospitalized patients with type II DM independent of other comorbid conditions. The pathogenesis of this association is not known warranting further investigation.

Adverse maternal outcomes in women with asthma versus women without asthma

The purpose of this retrospective cohort study was to examine differences in adverse maternal outcomes between pregnant women with asthma and pregnant women without asthma. A total of 7,777 pregnant patients with asthma were abstracted from a national database. The comparison group was 31,108 women, randomly selected from 541,719 pregnant women without asthma. Logistic regression was used to examine the relationship of asthma to 12 maternal outcome measures. Odds ratios were used to approximate the association of how much more likely pregnant women with asthma were to have adverse maternal outcomes. Pregnant women with asthma were more likely to have adverse maternal outcomes than did the pregnant women without asthma.

Diagnosis and treatment of peripartum bleeding

Severe peripartum hemorrhage (PPH) contributes to maternal morbidity and mortality and is one of the most frequent emergencies in obstetrics, occurring at a prevalence of 0.5-5.0%. Detection of antepartum risk factors is essential in order to implement preventive measures. Proper training of obstetric staff and publication of recommendations and guidelines can effectively reduce the frequency of PPH and its resulting morbidity and mortality. Therefore, an interdisciplinary expert committee was formed, with members from Germany, Austria, and Switzerland, to summarize recent scientific findings. An up-to-date presentation of the importance of embolization and of the diagnosis of coagulopathy in PPH is provided. Furthermore, the committee recommends changes in the management of PPH including new surgical options and the off-label use of recombinant factor VIIa.

Acute and chronic respiratory diseases in pregnancy: associations with spontaneous premature rupture of membranes

OBJECTIVE

To examine whether acute and chronic respiratory diseases are associated with an increased risk of spontaneous premature rupture of the membranes (PROM).

METHODS

We used the 1993-2004 National Hospital Discharge Survey data of singleton deliveries in the USA (N = 41 250 539). The International Classification of Diseases Ninth Revision was utilized to identify acute (acute upper respiratory diseases, viral/bacterial pneumonia, and acute bronchitis/bronchiolitis) and chronic (chronic bronchitis and asthma) respiratory conditions and spontaneous PROM. All analyses were adjusted for potential confounders.

RESULTS

The incidence of PROM was 5%, and rates of acute and chronic respiratory conditions were 2.1 and 9.5 per 1000 pregnancies, respectively. Chronic bronchitis was associated with a reduced risk of PROM (RR 0.39, 95% CI 0.31, 0.48). Asthma was significantly associated with PROM at preterm (RR 1.15, 95% CI 1.14, 1.17) and term (RR 1.27, 95% CI 1.23, 1.30). Stratification by race showed that acute upper respiratory disease was associated with preterm PROM in whites (RR 1.90, 95% CI 1.71, 2.11) and blacks (RR 6.76, 95% CI 5.67, 8.07). Viral/bacterial pneumonia was associated with preterm PROM in blacks and term PROM in both races. Asthma was associated with term PROM in blacks but not whites.

CONCLUSIONS

Acute respiratory diseases and asthma during pregnancy are associated with spontaneous PROM, with substantially stronger association among blacks than whites. We speculate that timely diagnosis and treatment, coupled with closely mentoring of pregnant women may help reduce the rate of PROM and associated complications.

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.

Fetal growth restriction and subsequent pregnancy risks

Fetal growth restriction can result from a variety of intrinsic or extrinsic insults, resulting from maternal, fetal, and placental factors. Determining the underlying cause of poor fetal growth can be difficult but is essential for assessing potential risks for future pregnancies. Importantly, recurrence risks greatly depend on these underlying conditions. Understanding these risks can allow more appropriate patient counseling and may influence management strategies to optimize future pregnancies.

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.

Safety of leukotriene receptor antagonists in pregnancy

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL IMPLICATIONS

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

The safety of asthma medications during pregnancy

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

Use of anti-asthmatic drugs during pregnancy. 3. Congenital malformations in the infants

OBJECTIVE

To study the risk for congenital malformations among infants whose mothers used anti-asthmatic drugs during pregnancy.

MATERIALS AND METHODS

We studied 24,750 infants whose mothers reported the use of anti-asthmatic drugs in early pregnancy. Infants were identified from the Swedish Medical Birth Register where drug use reported at the first maternal health care visit is recorded. Congenital malformations among the infants born were identified from that register, the Swedish Register of Congenital Malformations, and the Hospital Discharge Register. Rates of malformations among infants exposed to anti-asthmatics were compared with the background population rate of malformations (4.7%) after adjustment for year of birth, maternal age, parity, smoking, and previous miscarriages.

RESULTS

A weak increase in the risk for a congenital malformation was seen (odds ratio =1.09, 95% CI=1.03-1.15) which could not be explained by the confounders studied. The risks for three specific types of malformations appeared to be increased: relatively severe cardiac defects, orofacial clefts and specifically median cleft palate, and anal atresia. For the two last mentioned groups, use of anti-asthmatics with inhaled corticosteroids showed a higher odds ratio than use of other anti-asthmatics, but the differences could be random.

CONCLUSIONS

Maternal asthma and use of anti-asthmatic drugs carry no major risk for congenital malformations in the offspring, but a slight teratogenic effect cannot be excluded. It may be due to asthma, and arguments for a stronger effect of inhaled corticosteroids than of other anti-asthmatics are weak.

Use of anti-asthmatic drugs during pregnancy. 1. Maternal characteristics, pregnancy and delivery complications

OBJECTIVE

To study, in a large cohort, the association between the use of anti-asthmatic drugs during pregnancy and pregnancy complications.

METHODS

Using the Swedish Medical Birth Register, we identified 24,369 women who reported the use of anti-asthmatic drugs in early pregnancy and 7778 women who were prescribed such drugs later during pregnancy by antenatal care system centres, during the period July 1, 1995 up to and including 2004. We studied maternal characteristics and pregnancy and delivery complications. Comparisons were made with all women having given birth to a child recorded in the register during this period.

RESULTS

Women using anti-asthmatic drugs were characterized by a young maternal age, low parity, increased rate of smoking, low education, and high body mass index. An association with subfertility was also observed. Pre-existing diabetes did not occur in excess. A number of pregnancy and delivery complications occurred at an increased rate with the use of anti-asthmatic drugs, notably when three or more such drugs had been used: gestational diabetes [odds ratio (OR)=1.59], preeclampsia (OR=1.44), haemorrhage at delivery (OR=1.32) and premature rupture of membranes (OR=1.59); no excess of placenta abruption or previa was found. Primary weak contractions occurred more often than expected in women that used anti-asthmatic drugs (OR=1.15), and this was tentatively linked to the use of beta-2 adrenergic agonists. Most of the increased risk for caesarean section (OR=1.79) could be explained by these pregnancy complications. An increased risk for delivery induction (OR=1.74) was found among deliveries that did not start with a caesarean section.

CONCLUSION

An increase risk of pregnancy complications occurs with the use of anti-asthmatic drugs by pregnant women, which results in an increased rate of caesarean sections.

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.