Australian Birth Defects Society

A Society devoted to the study of birth defects


MotherSafe is a free telephone service for the women of NSW, based at the Royal Hospital for Women, Randwick.

October means spring, and that means:Allergies and Hay Fever

Many of my patients suffer from seasonal allergies, which seem to be worse in pregnancy!

I know that I can confidently recommend the older, sedating antihistamines like dexchlorpheniramine.† I also recommend that my patients who would normally use inhaled budesonide may continue to do so. Both of these medicines are Australian TGA pregnancy category A. Some of my patients usually use the newer non-sedating antihistamines, or have responded better to a newer inhaled steroid. What can I tell them, when they get pregnant having already used these medicines? Should I change their medicine to the older drugs now that they are pregnant?

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Nasal congestion is one of the common discomforts of pregnancy, and many women will report that their usual allergies seem more troublesome in pregnancy.

Although it seems reasonable based on the pregnancy categories, to change the pregnant patient to a category A product, this may be unacceptable if the patient finds the older antihistamine too sedating for tasks like driving or working. Many of the newer non-sedating antihistamines used to treat allergies have been studied in pregnant women, with no evidence to support any increased risk. Therefore you may be reassuring to a woman who has been inadvertently exposed in early pregnancy. Where a pregnant patient needs ongoing systemic treatment and has a preference for continuing to use a non-sedating product, it is acceptable that they do so. Inhaled steroids have been used by many pregnant women throughout pregnancy, with numerous studies indicating no increased risk attributable to the medication. The oldest and most frequently studied inhaled steroid is budesonide, hence itís category A status. All inhaled steroids are delivered in microgram dosage, and even the newest of these is not anticipated to increase pregnancy risk. Patients who have used these inhalers in early pregnancy may also be reassured that their baby has no extra risk of having a birth defect, over and above the expected population risk. Where a newer product treats the patient more effectively than the budesonide, it is reasonable that they continue with their usual medication.

Locally acting eye drops and locally acting nasal spray decongestants are not expected to increase pregnancy risk where used appropriately and in usual doses.


Patients may find the factsheet on the MotherSafe website helpful, it can be found here:

Page updated 10 October 2016

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