Allergy Medicines During Pregnancy

Which drugs are safe or unsafe?

It’s understandable that a lot of women don’t like to take unnecessary medicines when they’re pregnant. No mother-to-be would ever want to place her baby at an increased risk of a birth defect caused by medication. However, allergies can make some woman so miserable that medications may be needed just so that allergy symptoms are not taking over their lives.

Pregnant woman having cold
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According to the Food and Drug Administration (FDA), no medicines are considered completely safe in pregnancy. This is because no pregnant woman would want to sign up for a medication safety study while she is pregnant.

Therefore, the FDA has assigned risk categories to medications based on use in pregnancy:

  • Category A medications are medications in which there are good studies in pregnant women showing the safety of the medication to the baby in the first trimester. Few medications are in this category and no asthma medications are rated category A.
  • Category B medications have been studied in pregnant animals, which show that they are relatively safe, but no human studies are available.
  • Category C medications may result in adverse effects on the fetus when studied in pregnant animals, but the benefits of these drugs may outweigh the potential risks in humans.
  • Category D medications show clear risk to the fetus, but there may be instances in which the benefits outweigh the risks in humans.
  • Category X medications show clear evidence of birth defects in animals and/or human studies and should not be used in pregnancy.

Generally speaking, allergy medications are classified as either Pregnancy Category B or Category C.


Older antihistamines, such as chlorpheniramine, are the preferred agents to treat allergic rhinitis during pregnancy and are both Category B medications.

Newer antihistamines such as over-the-counter loratadine (Claritin, generic forms) and cetirizine (Zyrtec, generic forms) are also Pregnancy Category B medications. A newer prescription antihistamine that is Pregnancy Category B is Xyzal (levocetirizine).

Medicated Nasal Sprays

Cromolyn nasal spray is helpful in treating allergic rhinitis if it is used before exposure to an allergen and prior to the onset of symptoms. This medication is Pregnancy Category B and is available over the counter.

If Cromolyn is not helpful, a nasal steroid spray called Rhinocort Aqua (budesonide) received a Pregnancy Category B rating. All other steroid nasal sprays are category C) and should be avoided during pregnancy.


Pseudoephedrine (known by the brand name Sudafed and others) is the preferred oral decongestant to treat allergies during pregnancy. Classified as Pregnancy Category C, pseudoephedrine is known to hazardous in certain situations.

Pseudoephedrine should not be used during the entire first trimester as is linked to a birth defect called gastroschisis in which the baby's intestines are found outside of the body.


Allergy shots can be continued during pregnancy, but it is not recommended to start this treatment while pregnant. Typically the dose of the allergy shots is not increased, and many allergists will cut the dose of the allergy shot by 50% during pregnancy.

Some allergists feel that allergy shots should be stopped during pregnancy given the risk of anaphylaxis and the resulting harm to the fetus. Other than anaphylaxis, no data shows that the allergy shots themselves are actually harmful to the fetus.

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  1. Kar S, Krishnan A, Preetha K, Mohankar A. A review of antihistamines used during pregnancyJ Pharmacol Pharmacother. 2012;3(2):105–108. doi:10.4103/0976-500X.95503

Additional Reading
  • Allergen Immunotherapy Practice Parameters. Ann Allergy Asthma Immunol. 2003; 90:S1-40.
  • Dykewicz MS, Fineman S, editors. Diagnosis and Management of Rhinitis: Complete Guidelines of the Joint Task Force on Practice Parameters in Allergy, Asthma and Immunology.