Asthma in pregnancy: management strategies

Management of critical asthma syndrome during pregnancy

One-third of pregnant asthmatics experience a worsening of their asthma that may progress to a critical asthma syndrome (CAS) that includes status asthmaticus (SA) and near-fatal asthma (NFA). Patients with severe asthma before pregnancy may experience more exacerbations, especially during late pregnancy. Prevention of the CAS includes excellent asthma control involving targeted early and regular medical care of the pregnant asthmatic, together with medication compliance. Spontaneous abortion risk is higher in pregnant women with uncontrolled asthma than in non-asthmatics. Should CAS occur during pregnancy, aggressive bronchodilator therapy, montelukast, and systemic corticosteroids can be used in the context of respiratory monitoring, preferably in an Intensive Care Unit (ICU). Systemic epinephrine should be avoided due to potential teratogenic side-effects and placental/uterine vasoconstriction. Non-invasive ventilation has been used in some cases. Intratracheal intubation can be hazardous and rapid-sequence intubation by an experienced physician is recommended. Mechanical ventilation parameters are adjusted based on changes to respiratory mechanics in the pregnant patient. An inhaled helium-oxygen gas admixture may promote laminar airflow and improve gas exchange. Permissive hypercapnea is controversial, but may be unavoidable. Sedation with propofol which itself has bronchodilating properties is preferred to benzodiazepines. Case reports delineating good outcomes for both mother and fetus despite intubation for SA suggest that multidisciplinary ICU care of the pregnant asthmatic with critical asthma are feasible especially if hypoxemia is avoided.

Asthma medication use during pregnancy, wheeze and estimated exposure to ambient nitrogen dioxide

Risk of wheeze associated with ambient NO2 exposure is higher for pregnant asthmatics who have reduced their medication.

Investigating Women's Experiences of Asthma Care in Pregnancy: A Qualitative Study

Background : Most asthmatic women have normal pregnancies and complications are infrequent when their asthma is well-controlled. Symptom control and medical treatment are concerning to pregnant asthma suffers, as is the impact that their illness and treatment might have on their unborn baby. The aim was to investigate in a qualitative study the thoughts and feelings of women's experiences of asthma in pregnancy. Twenty-two women with asthma who had a pregnancy within two years were asked to participate. Seven women were interviewed when data saturation was achieved. Interviews were transcribed and analysed using the 'Framework' Method, independently analysed by two researchers and consensus reached concerning the construction of themes. The key themes that emerged were Asthma and pregnancy; Pregnancy and post-natal experiences; and Health professionals. These findings are globally interesting because of the prevalence of maternal asthma and they illustrate participants' experiences concerning their asthma care and their views on its improvement. Pregnant asthmatic women have concerns about their care and treatment which might be alleviated by outreach, joint working between respiratory doctors and nurse specialists, midwives and General Practice nurses. Targeted educational activities could form a part of this care delivery.

Risk of congenital malformations for asthmatic pregnant women using a long-acting β₂-agonist and inhaled corticosteroid combination versus higher-dose inhaled corticosteroid monotherapy

BACKGROUND

Current recommendations for managing persistent asthma during pregnancy when low-dose inhaled corticosteroids (ICSs) are insufficient include adding a long-acting β₂-agonist (LABA) or increasing the ICS dose. However, there are no data to help clinicians evaluate the safest regimen during pregnancy.

OBJECTIVE

We sought to compare the risk of major congenital malformations in asthmatic women exposed to a LABA plus ICS combination and those exposed to ICS monotherapy at higher doses during the first trimester.

METHODS

A cohort of asthmatic pregnant women exposed to ICSs during the first trimester who delivered between January 1990 and March 2009 was established. The primary outcome was major malformation recorded at birth or during the first year of life. Two subcohorts were established as follows: (1) users of a LABA plus low-dose ICS combination or users of a medium-dose ICS and (2) users of a LABA plus medium-dose ICS combination or users of a high-dose ICS. Generalized estimating equations were used to compare the risk of major malformations between the groups.

RESULTS

In one subcohort there were 643 women who used a LABA plus low-dose ICS and 305 who used a medium-dose ICS; the other subcohort included 198 users of a LABA plus medium-dose ICS and 156 users of a high-dose ICS. The prevalence of major malformations was 6.9% and 7.2%, respectively. The adjusted odds ratio for major malformations was 1.1 (95% CI, 0.6-1.9) when a LABA plus low-dose ICS was used compared with a medium-dose ICS and 1.2 (95% CI, 0.5-2.7) when a LABA plus medium-dose ICS was used compared with a high-dose ICS.

CONCLUSION

The risk of major malformations was similar with a LABA plus ICS combination and ICS monotherapy at higher doses, suggesting that both therapeutic options can be considered during pregnancy.

Oxytocin: an unexpected risk for cardiologic and broncho-obstructive effects, and allergic reactions in susceptible delivering women

Oxytocin (Sintocynon) is considered an uncommon cause of severe allergic reactions during delivery. We have recently shown that allergic sensitization to latex might constitute an important predisposing risk factor for anaphylaxis after the first infusion of oxytocin during delivery.Some oxytocin cardiovascular activities such as lowering blood pressure, negative cardiac inotropy and cronotropy, parasympathetic neuromodulation, vasodilatation etc. can induce significant side effects mimicking cardiac anaphylaxis, and constitute an additional differential diagnostic problem in delivering women with suspected or real allergic background. Finally, some ex vivo models have shown that oxytocin, under pro-inflammatory cytokines stimulation, such as those occurring in asthma, may induce contraction of smooth muscle and airway narrowing.This background suggests that allergic sensitization to latex allergens constitutes a significant but underestimated risk factor for triggering severe systemic reactions after the infusion of oxytocin and, consequently, there is a need of particular attention in managing delivering women suffering from latex allergy and bronchial asthma. An accurate anamnestic, clinical and diagnostic evaluation, latex-free anesthesiological setting, use of oxytocin-alternative agents and, if necessary, a drug premedication are likely to reduce the risk of anaphylactic/broncho-obstructive reactions in these women.

Incidence and risk factors for exacerbations of asthma during pregnancy

Background

Asthma is one of the most common chronic diseases among pregnant women. Acute exacerbations of asthma during pregnancy have an unfavorable impact on pregnancy outcome. This review provides an overview of current knowledge of incidence, mechanisms, and risk factors for acute exacerbations of asthma during pregnancy.

Methods

A narrative literature review was carried out using the PubMed database.

Results

During pregnancy, up to 6% of women with asthma are hospitalized for an acute exacerbation. The maternal immune system is characterized by a very high T-helper-2:T-helper-1 cytokine ratio during pregnancy and thereby provides an environment essential for fetal survival but one that may aggravate asthma. Cells of the innate immune system such as monocytes and neutrophils are also increased during pregnancy, and this too can exacerbate maternal asthma. Severe or difficult-to-control asthma appears to be the major risk factor for exacerbations during pregnancy, but studies also suggest that nonadherence with controller medication and viral infections are important triggers of exacerbations during pregnancy. So far, inconsistent findings have been reported regarding the effect of fetal sex on exacerbations during pregnancy. Other risk factors for exacerbation during pregnancy include obesity, ethnicity, and reflux, whereas atopy does not appear to be a risk factor.

Discussion

The incidence of asthma exacerbations during pregnancy is disturbingly high. Severe asthma – better described as difficult-to-control asthma – nonadherence with controller therapy, viral infections, obesity, and ethnicity are likely to be important risk factors for exacerbations of asthma during pregnancy, whereas inconsistent findings have been reported with regard to the importance of sex of the fetus.