Seasonal allergies during pregnancy can either improve or worsen.
Often the pregnancy hormones will increase the amount of nasal congestion and make allergy symptoms worse. This type of nasal congestion is often treated successfully with nasal saline drops (3 to 6 per nostril) followed by blowing your nose.
Most allergy medications taken before getting pregnant can be used during the pregnancy as well. However, check with your health care provider before using them. Allergy testing during pregnancy is not done due to the risk of a severe reaction known as anaphylaxis.
Antihistamines that can be used safely in pregnancy are Cetirizine (Zyrtec®) and Loratidine (Claritin®). Over-the-counter oral Pseudoephedrine (Sudafed®) can usually be used as well, but many health care providers prefer that you use it after the first trimester is over.
Nasal steroids are felt to be safe in pregnancy and can be helpful if the allergies give you a runny nose. Allergy shots can be continued during the pregnancy, but often women choose to stop taking them.