The safety of the medication is related to the effect on the fetus. It is generally safer to use nebulized inhaled glucocorticosteroids, such as budesonide or beclomethasone, because inhaled glucocorticosteroids are local medications that enter the systemic blood circulation in very small amounts, and the dosage is relatively small, so they generally do not pass through the placenta and affect the fetus. Because inhaled glucocorticosteroids are topical and enter the systemic circulation in small amounts, they do not affect the fetus through the placenta and have relatively mild side effects, making them safer to use during acute asthma attacks in pregnant women. Other asthma medications, such as beta agonists and theophylline, are less safe for use in pregnant women and should be used on a balance of pros and cons.