This document discusses the management of asthma during pregnancy. It notes that asthma is common in pregnancy, with respiratory changes occurring due to anatomical and hormonal factors. Pregnancy can affect asthma severity, with courses varying between women. Well controlled asthma is important for limiting risks to the pregnancy. Treatment follows a stepwise approach, initially using inhaled corticosteroids. Close monitoring is needed to prevent exacerbations while minimizing medication risks for the fetus. Inhaled beta-agonists are generally considered safe options for relief of symptoms during pregnancy.

1. ASTHMA IN
PREGNANCY
- Dr. PRAPULLA CHANDRA D

2. • INTRODUCTION
• RESPIRATORY CHANGES DURING PREGNANCY
• EFFECT OF PREGNANCY ON ASTHMA
• EFFECT OF ASTHMA ON PREGNANCY
• MANAGING ASTHMA DURING PREGNANCY
• MANAGING ASTHMA DURING LABOUR
• PERIPARTUM CARE
• SUMMARY

3. INTRODUCTION
• Asthma is one of the most common chronic medical conditions that
may complicate pregnancy, with a prevalence of 3.7 - 8.4% of all
pregnancies .
• Exacerbations are major clinical problem in pregnants with asthma
occurring in 20-36%.
• Asthma course improves in one-third, worsens in one-third and
remains unchanged in one-third of women during pregnancy.
• Pregnant women with asthma represent a special challenge for asthma
specialists and allergists. Asthma influences the outcome of pregnancy
and, vice versa, pregnancy affects asthma severity.

4. RESPIRATORY CHANGES DURING
PREGNACY
• ANATOMICAL CHANGES:
- Upper respiratory mucosal hyperemia and edema, glandular
hyperactivity.
- Thorax and Diaphragm :
- In the 1st trimester, subcostal angle can increase from 68-103
degrees.
- Diaphragm rises by upto 4cm

5. Airway edema,
Friability
Widened AP and
transverse diam.
Elevated
Diaphragm
Widened subcostal
Angle
Enlarging uterus
ANATOMIC EFFECTS

6. FUNCTIONAL CHANGES :
• The most striking changes are in the respiratory drive and minute
ventilation.
• Central respiratory drive, is increased by 13 weeks and continues to
increase to 37 weeks of gestation, returning to normal by 24 weeks
after delivery. These serial changes in respiratory drive appears to
correlate with changes in serum progesterone levels which either
stimulate respiration directly or increase the sensitivity of the
respiratory center to PCO2
• Increased minute ventilation is due to increased Tidal Volume.
• Respiratory rate is unchanged early and raises only above 10%, later
in pregnancy.
• O2 consumption increases 20%-30% in pregnancy owing to both
maternal and foetal demands.

8. LUNG VOLUME CHANGES :
Lung volume changes associated with pregnancy:
• Decreases : FRC(10-25%)
ERV(8-40%)
RV(7-22%)
• Increases : IC
• No change : TLC
VC

9. • Physiologic tests of large airway function including forced expiratory
volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC
ratio, mean forced expiratory flow during middle half of forced vital
capacity (FEF25–75), and peak expiratory flow rate (PEFR) remain
unaffected by pregnancy.
• These physiological parameters are useful indicators of asthma
control, and also helpful in differentiating dyspnea caused by asthma
from dyspnea caused by hyperventilation or pressure on the diaphragm
with late pregnancy.

10. EFFECT OF HORMONES ON
RESPIRATORY SYSTEM
• Hormonal changes in pregnancy affect the upper respiratory tract and
airway mucosa, producing hyperemia, mucosal edema, hypersecretion,
and increased mucosal friability.
• Estrogen is probably responsible for producing tissue edema, capillary
congestion, and hyperplasia of mucous glands.

11. • Progesterone may contribute to improved asthma via increased
minute ventilation, smooth muscle relaxation or cAMP induced
bronchodilation.
• On the other hand , progesterone may contribute to worsening
asthma via changes in b2-adrenoreceptor responsiveness and airway
inflammation
• Progesterone can act as partial glucocorticoid agonist and suppress
histamine release from basophils.

12. • Maternal plasma cortisol levels increase during pregnancy, which may
result in improvement in asthma control and reduced steroid
requirements. But the effects are variable.
• During pregnancy, amniotic fluid contains different prostaglandins
(PGE2, PGD2, PGF2-alfa). PGE2 is a bronchodilator where as the
others are bronchoconstrictors.
• But the relationship between increased levels of PGF2-alfa in
pregnancy and asthma exacerbations is not established.

13. EFFECT OF PREGNANCY ON ASTHMA
• Asthma course may worsen, improve or remain unchanged in pregnancy
occurring with equal frequency.
• General trends :
- Asthma was generally less severe during the last four weeks of pregnancy
- In women who improved, the improvement was gradual as pregnancy
progressed
- In women whose asthma worsened, the increase in symptoms was most
prominent between 29-36 weeks of gestation
- only 10% women showed asthma symptoms during labor and delivery
- The course of asthma in successive pregnancies in an individual patient
tends to be similar.

14. ACUTE EXACERBATIONS :
• Asthma exacerbations occur in 20 to 36 percent of pregnant asthmatic
patients.
• These exacerbations are not uniformly distributed over the course of
pregnancy.
• Exacerbations occurred most frequently during 17-24 weeks of
pregnancy.
• A peak incidence of severe asthma exacerbations during 14-24 weeks of
pregnancy and a peak incidence of mild asthma exacerbations during
25-32 weeks of pregnancy.

15. EFFECT OF ASTHMA ON PREGNANCY
• Asthma during pregnancy is associated with an increased incidence of
- perinatal mortality
- increased risks of spontaneous abortion
- hyperemesis
- preeclampsia
- prematurity and
- low birthweight infants

16. • Possible mechanisms for increased perinatal risks in pregnant
asthmatics are :
- chronic hypoxia and other physiological consequences of poorly
controlled asthma
- medications used to treat asthma
- Pathogenic or demographic factors associated with asthma but
actually not caused by the disease or its treatment, such as abnormal
placental function.

17. ASTHMA & PREGNANCY MANAGEMENT
Goals:
• Control symptoms, including nocturnal symptoms
• Prevent acute exacerbations
• No limitations on activities
• Maintain (near) normal pulmonary function
• Minimal use short-acting inhaled beta2- agonists
• Protect the mother and fetus from adverse effects

18. General Principles
• Preconception :
− Optimize asthma management.
• Few changes in treatment regimen are needed in pregnancy especially
if asthma is controlled.
- Avoid recently introduced medications whose safety in pregnancy is
not established.
- Use adequate doses of medications to control symptoms and avoid
hypoxia.
- It is essential to maintain adequate oxygenation to the fetus.

19. COMPONENTS OF ASTHMA
MANAGEMENT
• Objective measures for assessment and
monitoring
• Patient education
• Avoidance of factors contributing to asthma
severity
• Pharmacologic therapy
• Diagnose and treat rhinitis, sinusitis or
gastroesophageal reflux disease if present

20. The two primary goals of asthma management are
- optimization of ongoing asthma control
- prevention of acute exacerbations
• The general principles of pharmacologic therapy for asthma
during pregnancy are similar to those in non-pregnant
patients and involve a stepwise approach to achieve and
maintain asthma control.

21. STEPWISE APPROACH FOR THE
MANAGEMENT OF ASTHMA DURING
PREGNANCY

23. STEP 1 – MILD INTERMITTENT
ASTHMA
Clinical Presentation
• Symptoms : < 2 days/week
< 2 nights /month
• PEF or FEV1 : > 80%
• PEF variability : >20%
• TREATMENT :
- No daily medication needed.
- Severe exacerbations may occur, separated by long periods of normal
lung function and no symptoms. A course of systemic corticosteroid is
recommended.

24. STEP 2 – MILD PERSISTENT ASTHMA
Clinical Presentation
• Symptoms > 2 days/wk but < daily
> 2 nights/month
• PEF or FEV1 : > 80% predicted
• PEF variability : 20-30%
• PREFERRED TREATMENT : low dose inhaled corticosteroid
• Alternative : cromolyn, Leukotriene receptor antagonists or sustained
release theophylline to serum conc. Of 5-12 mcg/ml

25. STEP 3 – MODERATE PERSISTENT ASTHMA
• Daily symptoms, > 1 night/week
• PEF or FEV1 : 60 – 80% predicted
• PEF variability : > 30%
• PREFERRED TREATMENT :
Low-dose inhaled corticosteroid and long-acting beta2-agonist
OR
Medium-dose inhaled corticosteroid
If needed (particularly in patients with recurring severe exacerbations):
- Medium-dose inhaled corticosteroid and long acting inhaled beta2-agonist
• ALTERNATIVE TREATMENT:
- Low-dose inhaled corticosteroid and either theophylline or leukotriene receptor
antagonist.
If needed:
- Medium-dose inhaled corticosteroid and either theophylline or leukotriene
receptor antagonist.

26. STEP 4 – SEVERE PERSISTENT ASTHMA
Clinical Presentation
• Daily and frequent night symptoms
• PEF or FEV1 is: ≤ 60% predicted
• PEF variability : >30%
• PREFERRED TREATMENT:
- High-dose inhaled corticosteroid AND Long-acting inhaled beta2-agonist
AND, if needed,
- Corticosteroid tablets or syrup long term (2 mg/kg per day, generally not to exceed 60
mg per day). (Make repeat attempts to reduce systemic corticosteroid and maintain
control with high-dose inhaled corticosteroid.)
• ALTERNATIVE TREATMENT:
- High-dose inhaled corticosteroid AND Sustained release theophylline to serum
concentration of 5–12 mcg/mL.

27. • QUICK RELIEF FOR ALL PATIENTS :
- Short-acting bronchodilator: 2–4 puffs short-acting inhaled beta2-
agonist as needed for symptoms.
- Intensity of treatment will depend on severity of exacerbation; up to
3 times at 20-minute intervals or a single nebulizer treatment as needed.
Course of systemic corticosteroid may be needed.
- Use of short-acting inhaled beta2-agonist >2 times a week in
intermittent asthma (daily, or increasing use in persistent asthma) may
indicate the need to initiate (increase) long-term-control therapy.

29. ASSESSING DRUG SAFETY IN
PREGNANCY

32. ANTI-INFLAMMATORY
INHALED STEROIDS
ORAL STEROIDS

33. LUKOTRIENE MODIFIERS
ANTI-HISTAMINES

34. INHALED B2 AGONISTS
• The majority of reports provide reassurance regarding the use of
inhaled beta-agonists during pregnancy. Clinical experience is greater
with the older agents (eg albuterol) than with the newer ones (eg
formoterol, salmeterol).
• SHORT-ACTING BETA-ADRENERGIC AGONISTS —
- The SABAs are used to provide quick relief of asthma symptoms
and appear to be relatively safe during pregnancy.
- Albuterol is recommended as the short-acting beta agonist of choice.
- SABA use is a marker for poorly-controlled asthma and more
frequent exacerbations, which may independently contribute to the
development of congenital anomalies

35. LONG ACTING B2 AGONISTS
• A retrospective study showed that salmeterol and formoterol do not
increase the risk of delivering low birth weight, small for gestational age,
or preterm infants.
• So, continuation of a LABA during pregnancy is reasonable if a LABA is
needed (in combination with an inhaled glucocorticoid) to achieve asthma
control before pregnancy.
• Human safety data for newer LABAs, such as indacaterol, olodaterol, and
vilanterol are lacking.
• When comparing a combination LABA plus ICS versus monotherapy with
a higher dose of the inhaled glucocorticoid, the risk of congenital
malformations appears similar.

36. ORAL / SYSTEMIC CORTICOSTEROIDS
• Systemic glucocorticoids have been used extensively during pregnancy to
treat asthma exacerbations and rarely for control of severe asthma.
• The potential risks of gestational oral glucocorticoids must be balanced
against the risks to the mother or infant of inadequately treated asthma.
• As the risks of severe uncontrolled asthma include maternal or fetal
mortality, these risks are considered to be greater than the potential risk
of systemic glucocorticoids.
• May cause Congenital malformations (primarily cleft palate),
preeclampsia, gestational diabetes, low birth weight, and neonatal adrenal
insufficiency.

37. INHALED CORTICOSTEROIDS
• Budesonide is the preferred inhaled glucocorticoid for use during
pregnancy, as more published gestational human data are available for
that medication.
• other inhaled glucocorticoids could be continued if the patient was
well controlled on one of these medications prior to pregnancy.
• The rate of congenital malformations with the use of inhaled
budesonide is same as that of the general population.

38. ANTI-CHOLINERGIC AGENTS
• Anticholinergic agents such as ipratropium, glycopyrrolate, and
tiotropium, are not generally used as a primary form of therapy for
asthma.
• LAMAs are usually reserved for patients with moderate-to severe
asthma that is not controlled with a LABA-inhaled glucocorticoid
combination.
• Inhaled ipratropium, with minimal chronotropic effects on fetus, is
commonly used, and is considered to be safe during pregnancy.
• The safety of inhaled tiotropium, aclidinium, glycopyrrolate, and
umeclidinium during pregnancy is uncertain.

39. LEUKOTRIENE MODIFIERS
• Montelukast or zafirlukast considered as alternative but NOT preferred
therapy for mild persistent asthma or as add-on therapy to inhaled
glucocorticoids, especially for patients who have shown a uniquely
favorable response prior to pregnancy.
• Zileuton is not recommended as adverse effects were noted.

40. METHYL XANTHINES
• The clinical use of methyl xanthines (theophylline, aminophylline)
during pregnancy is limited because of the potential for altered
metabolism during pregnancy, the need for drug level monitoring, and
the potential for fetal tachycardia and irritability at the time of delivery.
• Theophylline does not increase the risk of fetal anomalies.

41. IMMUNOTHERAPY
• The initiation of subcutaneous or sublingual immunotherapy is not
recommended during pregnancy due to the potential harm to the fetus,
if any systemic allergic reaction occur.
• However, patients who are tolerating maintenance immunotherapy and
deriving benefit may continue it.

43. NON-PHARMACOLOGICAL
MANAGEMENT
• Includes :
- Patient education,
- Avoidance of irritant (eg, cigarette smoke)
- Control of allergenic triggers of asthma.

44. 1. PATIENT EDUCATION
• The patients should be clearly explained, that it is safer for pregnant
women with asthma to take asthma medications than to have ongoing
symptoms or exacerbations of asthma.
• Reassurance that safe and adequate asthma treatment is possible
during pregnancy and that good asthma control can help to minimize
the risk of complications.

45. 2. SMOKING CESSATION
• smoking may predispose the patient to asthma exacerbations, bronchitis or
sinusitis, and therefore necessitate an increased need for medication.
• cigarette smoking is associated with numerous adverse pregnancy
outcomes, including
- spontaneous pregnancy loss,
- placental abruption,
- preterm premature rupture of membranes(PPROM),
- placenta previa,
- preterm labor and delivery,
- low birth weight,
- ectopic pregnancy.

46. 3. CONTROL OF ENVIRONMENTAL
TRIGGERS
• It helps to reduce the need for pharmacologic intervention.
• This includes avoiding exposure to allergens and to nonspecific airway
irritants, such as tobacco smoke, dust, and environmental pollutants.
• Particular allergens of concern are dander from pets and antigens from
household dust mites.

47. MONITORING
• In pregnant asthmatics
Asthma control is monitored by
- SPIROMETRY – MONTHLY
- In severe Asthma,
PEAK FLOW METRY - Twice daily
Upon waking up &
After 12 hr

48. ACUTE EXACERBATIONS
• Acute asthma exacerbations are common during pregnancy and
increase the risk of pre-eclampsia, gestational diabetes, placental
abruption and placenta previa.
• The recommended pharmacotherapy of acute asthma during
pregnancy does not differ substantially from the management in non-
pregnant patients.
• Intensive monitoring of both mother and fetus is essential.

49. MATERNAL MONITORING
• Continuous measurement of oxygen saturation by pulse oximetry
(SpO2 ) is essential, aiming for a SpO2 ≥95 percent.
• Measurement of expiratory airflow with a peak flowmeter (or
spirometer) is the best method for objective assessment of the severity
of an asthma attack.
• A chest radiograph is not routinely indicated for the majority of
asthma exacerbations and is reserved for patients with suspected
pneumonia, pneumothorax, or impending or actual respiratory failure.

50. FETAL MONITORING
• Fetal heart rate monitoring is the best available method for
determining whether the fetus is adequately oxygenated.
• After 23-24 weeks of gestation, non-invasive fetal heart rate
monitoring is appropriate during asthma exacerbations requiring
emergency department treatment or hospitalization and biophysical
profile of fetus is noted.

51. SUPPORTIVE CARE
• Maternal positioning – In general, pregnant patients with acute
asthma should rest in a seated or lateral position, rather than supine,
particularly in the third trimester, to avoid aortocaval compression by
the gravid uterus.
• Hydration – Intravenous fluids are not necessary unless the patient is
unable to maintain oral hydration.
• Supplemental oxygen — Supplemental oxygen (initially 3 to 4 L/min
by nasal cannula) should be administered, adjusting the fraction of
inspired oxygen (FiO2 ) to maintain a PaO2 of at least 70 mmHg
and/or oxygen saturation by pulse oximetry of 95 percent or greater

52. PHARMACOTHERAPY IN
EXACERBATIONS
• The recommended agents for management of acute asthma
exacerbations in pregnant patients are the same as for asthma
exacerbations in non-pregnants.
• These agents include inhaled short-acting beta agonists, inhaled
anticholinergic agents, oral or intravenous glucocorticoids, and, if
appropriate, intravenous magnesium sulphate.

53. • Systemic glucocorticoids : Patients should be reassured that the
benefits of oral glucocorticoids in preventing exacerbations from
becoming life-threatening asthma outweigh any risk to the mother or
fetus.
• Ipratropium – Ipratropium is often used to treat severe acute asthma
exacerbations.
• Intravenous magnesium sulfate – Intravenous magnesium sulfate
may be beneficial in acute severe asthma as an adjunct to inhaled beta
agonists and intravenous glucocorticoids.

54. ASTHMA MANAGEMENT DURING
LABOR AND DELIVERY
• Only about 10% to 20% of women develop an exacerbation of asthma
during labor and delivery.
• Asthma medications should be continued during labor and delivery.
• If a systemic steroid has been used in the previous month, then stress-
dose steroid should be administered during labor to prevent maternal
adrenal crisis.

55. PERIPARTUM CARE
• Oxytocin is the drug of choice for induction of labor and control of
postpartum haemorrhage.
• Analogs of prostaglandin F2-alpha can cause bronchoconstriction, and
should not be used for termination of pregnancy, cervical ripening,
induction of labor, or control of uterine hemorrhage. Prostaglandin E2
(in gel or suppository form) and prostaglandin E1 (misoprostol) are
safer.

56. • For peripartum pain control, morphine and meperidine should be
avoided, as they can induce histamine release from skin mast cells.
Fentanyl or Butorphemol are alternatives.
• Epidural Anaesthesia is preferred. If general, Ketamine is used
because of its bronchodilatory effect.
• Ergot derivatives are avoided.
• If high doses of SABA have been given during labor and delivery,
blood glucose levels should be monitored in the baby (especially if
preterm) for the first 24 hours.

60. SUMMARY
• Asthma is one of the most common chronic medical conditions that
may complicate pregnancy, with a prevalence of 3.7 - 8.4% of all
pregnancies .
• Asthma may improve, worsen, or remain unchanged in severity during
pregnancy.
• The two primary goals of asthma therapy during pregnancy are the
prevention of acute exacerbations and optimization of ongoing
pulmonary function.

61. • The four important components of effective asthma therapy during
pregnancy are:
- Objective monitoring of maternal lung function and fetal well being
as a guide to therapy.
- Proper control of environmental and other triggers for asthma
- Patient education
- Pharmacologic therapy
• The general principles of pharmacologic therapy for asthma during
pregnancy are similar to those in nonpregnant patients and involve a step-
wise approach.