Asthma Diagnosis and Management in Pregnancy

Effects of Pregnancy on Asthma

Approximately one-third of women experience improved asthma symptoms, one-third unchanged symptoms, and one-third worsened symptoms during pregnancy, with specific phenotypes like allergic or eosinophilic asthma more likely to worsen 2, 3
Asthma symptoms tend to be relatively stable during the first trimester and last month of pregnancy, with increased symptoms and medication needs more common during the second and third trimesters 2, 4
Overweight or obese pregnant women experience asthma exacerbations twice as frequently as healthy-weight pregnant women with asthma 2

Spirometry is the preferred method for objective assessment of lung function in pregnant women with suspected asthma, according to the American College of Allergy, Asthma, and Immunology 1
For initial diagnosis, spirometry is preferable to peak expiratory flow (PEF) measurement, as recommended by the American Thoracic Society 1

Uncontrolled asthma during pregnancy increases risks of pre-term birth, low birthweight, small for gestational age infants, pre-eclampsia, gestational diabetes, and perinatal mortality 3, 4
Active asthma management during pregnancy reduces these risks, as stated by the European Respiratory Society 3, 5
Monthly monitoring of asthma symptoms and lung function is recommended throughout pregnancy, with serial ultrasound examinations starting at 32 weeks gestation considered for patients with suboptimally controlled asthma 1, 4