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

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

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

Inhaled corticosteroid use during pregnancy among women with asthma: A systematic review and meta-analysis

BACKGROUND

Studies demonstrate the prescription rate for inhaled corticosteroids (ICS) decreases in early pregnancy, possibly increasing exacerbation risk. This could be related to non-adherence to prescribed asthma medication or medication cessation by the patient or doctor. ICS use during pregnancy has not previously been summarized in a systematic review.

OBJECTIVE

The aim of this systematic review and meta-analysis was to evaluate the use of ICS during pregnancy among asthmatic women, specifically: (1) the prevalence of use, (2) changes of use during pregnancy compared with pre-pregnancy and (3) medication adherence among ICS users.

METHODS

We systematically searched literature in Embase, MEDLINE, CINAL and Cochrane, using terms related to asthma, pregnancy and medication use. All English articles reporting ICS among pregnant women with asthma were included. Prevalence, changes in ICS use during pregnancy and ICS adherence were pooled using STATA (version 15.0, StataCorp USA).

RESULTS

A total of 4237 references were retrieved in the initial search. Screening and review led to the inclusion of 52 articles for one or more aims (Aim 1: N = 45; Aim 2, N = 13; and Aim 3, N = 5). The pooled prevalence of ICS use during pregnancy was 41% (95%CI 36%-45%); 49% (95%CI 44%-55%) in Europe, 39% (95%CI 32%-47%) in Australia and 34% (95%CI 27%-41%) in North America. In eight prescription databases, ICS prescription rates lowered in the first trimester of pregnancy, compared with pre-pregnancy, increased in the second trimester and decreased in the third trimester. Five studies reported ICS adherence among pregnant women, using four measures of self-reported non-adherence. In two comparable studies, pooled ICS non-adherence was 40% (95%CI 36%-44%).

CONCLUSIONS

The prevalence of ICS use among pregnant women with asthma is 41% and varies widely between countries and continents, and prescription rates for ICS change throughout pregnancy. More studies are needed to investigate ICS adherence during pregnancy in women with asthma.

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.

[Asthma during pregnancy: effects on fetal well-being, and maternal and perinatal complications]

OBJECTIVE

To assess the effects of maternal asthma on pregnancy, analyzing the consequences of the severity of the disease in the impairment of fetal well-being, as well as the related maternal and perinatal complications.

METHODS

A retrospective study with 117 pregnancies complicated by maternal asthma and with no other comorbidities, in the period from January, 2005 to December, 2010. Inclusion criteria were as follows: singleton pregnancy; pregnant women diagnosed with asthma prior to pregnancy; initiation of prenatal care before the 28(th) week of pregnancy; birth at this institution; newborn weighing over 500 g and gestational age at delivery of 22 weeks or more; absence of fetal malformations or chromosomal abnormalities; absence of maternal comorbidities. Asthma was classified as intermittent, mild persistent, moderate persistent, or severe persistent. The results of fetal biophysical profile and of Doppler velocimetry of the umbilical artery performed 14 days prior to birth were analyzed.

RESULTS

Of the total of 117 pregnant women with asthma, 41 (35.0%) had intermittent, 33 (28.2%) mild persistent, 21 (17.9%) moderate persistent, and 22 (18.8%) severe persistent asthma. There was no significant difference among the groups as to the type of birth: cesarean section was performed in 65.8% of the cases, maternal corticosteroid therapy was used at the moment of birth in 20.5%, the gestational age at birth averaged 38.6 weeks (SD 1.9 weeks), and birth weight averaged 3,056 g (SD 581g). The fetal biophysical profile performed during the antepartum period (n=90, 76.9%) showed a normal result (8 or 10) in 99% of the cases. Doppler velocimetry of the umbilical artery was assessed in 23.9% (n=28) of the pregnant women, and delivered normal results in 100% of the cases. The use of systemic corticosteroid therapy was significantly (p<0.001) different among the intermittent (4.9%), mild persistent (9.1%), moderate persistent (28.6%), and severe persistent (45.5%) groups. Regarding the beginning of birth, there was a higher proportion of elective cesarean section in the groups with moderate persistent asthma (52.5%) and severe persistent (54.6%) when compared to the intermittent (21.9%) and mild persistent (24.2%) groups (p=0.039).

CONCLUSION

The severity of maternal asthma does not appear to have any direct influence on perinatal outcomes, and does not compromise fetal well-being. Active conduct to enable a better maternal clinical condition provides a favorable prognosis for pregnancy complicated by asthma.

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.

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.

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.

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

Bronchial asthma is one of the most common maternal diseases complicating pregnancy. We assessed the risks of congenital abnormalities in a case-control population-based analysis using the dataset of the Hungarian Case-Control Surveillance of Congenital Abnormalities between 1980 and 1996. Of the 22,843 cases with congenital abnormalities, 511 (2.2%) had mothers with bronchial asthma, while of the 38,151 matched control subjects without congenital abnormalities 757 (2.0%) had mothers with bronchial asthma (unadjusted prevalence odds ratios [POR] 1.2; 95% CI: 1.0-1.3). In all mothers with bronchial asthma, a higher incidence of respiratory tract infections and higher drug intake could be observed. In the case group of medically recorded bronchial asthma, a slightly increased risk for club foot has been revealed. However, this weak association could be explained by the higher proportion of preterm births in this group. The main limitation of the analysis was that at the time of data collection only a small proportion of pregnant mothers were using anti-asthma medications recommended by the actual guidelines.

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.

Risk and benefit of drug use during pregnancy

Environmental teratogenic factors (e.g. alcohol) are preventable. We focus our analysis on human teratogenic drugs which are not used frequently during pregnancy. The previous human teratogenic studies had serious methodological problems, e.g. the first trimester concept is outdated because environmental teratogens cannot induce congenital abnormalities in the first month of gestation. In addition, teratogens usually cause specific congenital abnormalities or syndromes. Finally, the importance of chemical structures, administrative routes and reasons for treatment at the evaluation of medicinal products was not considered. On the other hand, in the so-called case-control epidemiological studies in general recall bias was not limited. These biases explain that the teratogenic risk of drugs is exaggerated, while the benefit of medicine use during pregnancy is underestimated. Thus, a better balance is needed between the risk and benefit of drug treatments during pregnancy. Of course, we have to do our best to reduce the risk of teratogenic drugs as much as possible, however, it is worth stressing the preventive effect of drugs for maternal diseases (e.g. diabetes mellitus and hyperthermia) related congenital abnormalities.