Is Management of Asthma is different in Pregnancy?

If Asthma is not Controlled

Risks of women’s health include: 1. High blood pressure during the pregnancy. 2. Pre-eclampsia a condition that causes high blood pressure and can affect the placenta, kidneys, liver and brain.

Risks to the fetus include:

1. Abnormally slow growth of the fetus (intrauterine growth retardation). When born, the baby appears small.
2. Birth before the 37th week of pregnancy (preterm birth).
3. Low birth weight.
4. Death immediately before or after birth (perinatal mortality) So good control of asthma is needed to ensure healthy outcome of mother and fetus (Table 1).

Pulmonary Function Changes in Pregnancy

Most of the physiological parameters of lung functions are altered in pregnancy. There is an increase in oxygen consumption of 20% with an increased maternal metabolic rate of 15% [5]. The functional residual capacity (amount of air remaining in the lungs during normal breathing) decreases by 17-20%; the residual volume (air remaining in the lungs after maximal expiration) decreases by 20- 25%; the tidal volume (air displaced between inhalation and exhalation with no extra effort) increases by 30–50%; the expiratory reserve volume (the air that can be further pushed out at the end of normal expiration) decreases by 5-15%; and the minute volume/ventilation (volume of air inhaled or exhaled in 1 minute) increases by 30-50% [5, 6, 7].

The respiratory rate, FEV1  and peak expiratory flow rate (PEFR) are unchanged. This makes the latter two very suitable methods for assessing pulmonary function in pregnancy [6, 7]. The changed minute ventilation and increased tidal volume results in a relative hyperventilation with a subsequent respiratory alkalosis (pH of 7.40 to 7.45; PCO2 of 28 to 32 mmHg) compensated for by renal excretion of bicarbonate. There is a mild increase in maternal arterial PO2 (106-110 mmHg) with the umbilical venous PO2 being lower than that of the placental venous channels. As such any maternal hypoxia quickly results in substantial fetal hypoxia. Coleman and Rund reported that a PO2 of 60 causes fetal jeopardy. The length of the hypoxia would relate to the degree of fetal compromise.

Asthma Treatment and Pregnancy

Virtually there is no difference between the management of bronchial asthma in pregnant women and non-pregnant women. Like all people with asthma, pregnant women need to have an asthma action plan to help them control inflammation and prevent and control asthma attacks & maintain record.

Although there is a general concern about any medication use in pregnancy the advantage of actively treating asthma in pregnancy markedly outweigh any potential risks of usual controller and reliever medications. For this reason, using medications to achieve good symptom control and prevent exacerbations is justified even when their safety in pregnancy has not been unequivocally proven. Use of ICS, beta-2 agonist, montelukast or theophylline is not associated with an increased incidence of fetal abnormalities [8]. Importantly, ICS reduce the risk of exacerbations of asthma during pregnancy. And cessation of ICS during pregnancy is a significant risk factor for exacerbations [8].

The current approach to management seeks to achieve optimal disease control, which means using medication and other management strategies to achieve minimal symptoms (ideally none) of asthma, optimal lung function, and to reduce the future risks of asthma exacerbations [8].

Pregnant women should note, whether fetal kicks decrease over time. If she notices less fetal activity during an asthma attack, contact with doctor or emergency immediately to get instructions.

Things to think about for asthma in pregnant women include the following: If more than one health professional is involved in the pregnancy and asthma care, they must communicate with each other about treatment. The obstetricians must be involved with asthma care. According to the current recommendation s regular monitoring of asthma monthly during pregnancy is recommended for all pregnant women with asthma [8].

Some women with asthma stop or reduce their use of asthma controller medication in early pregnancy [9], often without consulting their doctor, and reduced adherence with controller medication during pregnancy is associated with increased risk of asthma -related emergency department visits. The reason for abstaining controller medication is very likely to be fear of harmful effects of the drugs on the foetus [10]. Non-adherence to controller medication is, in general, a major risk factor for asthma exacerbations and the risk of having an exacerbation is reduced by more than 75% among women who are using controller medication regularly. Asthma exacerbation’s during the first trimester of pregnancy increase the risk of congenital malformation [11].

Monitor lung function carefully throughout your pregnancy to ensure that your growing fetus gets enough oxygen. Because asthma severity changes for about two- thirds of patients during pregnancy, should have monthly check ups with her doctor to monitor symptoms and lung function. Doctor will use either spirometry or a peak flow meter to measure lung function. Monitor fetal movements daily after 28 weeks [12].

If asthma is not well controlled or if patients have moderate or severe asthma, think about having ultrasound after 32 weeks to monitor fetal growth. Ultrasound exams can also help to check on the fetus after an asthma attack [12].

All patients should be educated regarding the relationship between asthma and pregnancy, and they should be taught about self-treatment, including inhaler techniques, adherence to medication, and control of potential environmental factors.

It is well -documented that active and passive tobacco smoke exposure is a major risk factor for worse asthma control, excessive decline in FEV 1, and impaired responses to ICS and oral steroids. Asthmatic women who are current smokers during pregnancy have more severe asthma exacerbations during pregnancy relative to women who are non -smokers [13].

Try to do more to avoid and control asthma triggers (such as tobacco smoke or house dust mites, pollen), so that you can take less medicine if possible. Many women have nasal symptoms, and there may be a link between increased nasal symptoms and asthma attack. Well control of nasal symptoms by applying safe nasal preparation (Budesonide nasal spray preferable), gastro esophageal reflux disorder (GERD), which is common in pregnancy, may also cause symptoms.

The appropriate management of common coexisting conditions that can aggravate asthma, such as rhinitis, sinusitis, and gastro esophageal reflux, can improve asthma control. Women who smoke must be informed of the potential adverse effects of smoking on the fetus, which may add to the fetal effects of uncontrolled asthma and should be strongly encouraged to quit. Advice on environmental control measures for reducing exposure to allergens can be provided on the basis of the results of allergy testing.

Medications for Asthma

Medications for asthma are divided into long-term controller medications that prevent the manifestations of asthma (inhaled corticosteroids, long-acting β- agonists, leukotriene modifiers, cromolyn, and theophylline) and rescue therapy that provides quick relief of symptoms (primarily short-acting inhaled β-agonists) [14, 15].

In pregnancy, LABA are considered for use in moderate to severe asthma, in combination with ICS therapy. Few studies have examined their safety in this context, most being post marketing surveillance studies or small cohort or case- control studies examining congenital malformations. One study reported no adverse outcomes among 65 pregnant women who used salmeterol [15].

A recent study from Quebec, found no significantly increased odds of any or major malformations with first trimester LABA use (adjusted OR 1.37, 95% CI 0.92, 2.17 for any malformations) [16]. There was an increased risk of major cardiac malformations (adjusted OR 2.38, 95% CI) among asthmatic users of LABA compared to non-users of LABA in another small group study [17]. Based on a longer period of availability, 2004 guidelines recommended salmeterol as the preferred LABA used in pregnancy [18].

Evidence of the efficacy of these drugs during pregnancy is largely extrapolated from studies involving patients who were not pregnant. To our knowledge, only two randomized, controlled trials specifically involving pregnant patients with asthma have been conducted. These studies showed that inhaled beclomethasone is more effective than theophylline in improving pulmonary function [19] in other studies. Theophylline was as effective as beclomethasone diproprianate but was associated with a higher side effect rate and higher discontinuation rates [20].

On balance, given the evidence in pregnancy and infancy for adverse outcomes from exacerbations during pregnancy including due to lack of ICS or poor adherence, and evidence for safety of usual doses of ICS and LABA and a low priority should be placed on stepping down treatment (however guided) until after delivery. and ICS should not be stopped in preparation for pregnancy or during pregnancy [8].

Neonatal hypoglycemia may be seen, especially in preterm babies, when high doses of Beta-agonists have been given within the last 48 hours prior to delivery. If high doses of SABA have been given during and before delivery, blood glucose levels should be monitored in the baby (especially if preterm) for the first 24 hours [8].

Oral corticosteroids: During the first trimester may have a slight increased risk of isolated cleft lip, with or without cleft palate, (0.3% versus 0.1%). There are also associations with preterm delivery, low birth weight and preeclampsia [21]. It is however, difficult to delineate what is an attributable effect from the corticosteroids versus the effects of severe or uncontrolled asthma.

Inhaled corticosteroids reduces risk of asthma exacerbations in pregnancy and improved lung function (FEV1) [1]. There are no data showing any increase in congenital malformations or adverse perinatal outcomes [22]. The majority of experience with ICS to date is with budesonide. The numbers of women taking Leukotriene inhibitor notably montelukast having no significant adverse effect are small with minimal data available [23] (Table 2).

Is the Flu Shot during Pregnancy Safe?

Yes, the flu shot during pregnancy is not only safe, it’s a must. The seasonal flu shot has been given safely to millions of pregnant women over many years and has not been shown to cause harm to expecting moms or their babies. Getting an influenza (flu) vaccine is the first and most important step in protecting against flu. Pregnant women should get a flu shot and not the nasal spray flu vaccine. Flu shots given during pregnancy help protect both the mother and her baby from flu. Vaccination has been shown to reduce the risk of flu- associated acute respiratory infection in pregnant women by up to one-half [24, 25].

There is good evidence that pregnant women have a higher chance  of developing complications if they get flu, particularly in the later stages of pregnancy. One of the most common complications of flu is bronchitis a chest infection that can become serious and develop into pneumonia.