Safety of Antihistamines During Pregnancy (2025)

If you're pregnant, you may wonder if it's safe to use antihistamines. An estimated 10% to 15% of pregnant people do use these drugs to treat allergic rhinitis (runny nose) as well as hives, nausea and vomiting, indigestion, and more.

Most antihistamines do not appear to be linked to birth defects in the limited studies that are available. Non-sedating antihistamines, such as Zyrtec (cetirizine) and Claritin (loratadine), may be OK for use. Check with your obstetrician before taking any medication during pregnancy.

Is It Safe to Take Antihistamines During Pregnancy?

A group of researchers from the United States and Singapore sought to determine the safety of antihistamines taken during the first trimester of pregnancy. The researchers examined data collected over a 12-year period, from 1998 to 2010, on over 13,000 babies born with birth defects, and compared them to nearly 7,000 babies without birth defects.

Approximately 14% of all babies had been exposed to various antihistamines the mother took during the first trimester of pregnancy. Some antihistamines, such as Benadryl (diphenhydramine) and Claritin, have increased in use by pregnant people over the years. The use of other antihistamines, such as chlorpheniramine (for cold symptoms) and Unisom (a sleep aid), has decreased.

Overall, researchers did not find that the birth defects that had previously been associated with exposure to certain antihistamines were associated with antihistamine exposure in their study. They also found new possible associations.

The authors concluded that the associations between antihistamines and birth defects in prior studies and in the current studies were most likely related to chance and not true causation.

Which Antihistamines Are Safe to Use in Pregnancy?

In a 2014 study conducted by the Centers for Disease Control and Prevention (CDC), researchers reviewed 54 published scientific articles that examined the link between antihistamine use during pregnancy and birth defects.

They found that the use of most types of antihistamines during pregnancy is not linked to birth defects. However, the researchers noted that certain antihistamine medications need to be further studied to determine their safety in pregnancy.

Although research suggests that many antihistamines are generally considered “safe” during pregnancy, some studies find first-generation drugs (like Benadryl and Unisom) should not be used by pregnant people. They should further be avoided when nursing because their sedative effects are passed through in breast milk.

Oral decongestants also should be avoided during the first trimester. It's recommended that you consult with your healthcare provider before taking any over-the-counter medications, to ensure that you understand the effects and any risks.

With allergy shots, most allergists will continue current allergy shots if a pregnant person is on maintenance dosing, tolerating shots well, and finding that they are improving allergy symptoms. If a pregnant person is not already on full-strength allergy shots, building up to higher concentrations is usually not warranted due to risk of possible anaphylaxis and the effects of anaphylaxis on the fetus.

Any medication taken during pregnancy is best taken for the shortest amount of time, and at the lowest dose that is effective for treating symptoms. The benefit of taking any medication needs to be weighed against the risk of not taking the medication.

Alternatives to Antihistamines During Pregnancy

During pregnancy, antihistamines aren't the only treatment option for symptom relief. For nasal congestion and sneezing, many people find that irrigating the sinuses with nasal saline can relieve symptoms. Be sure to discuss the use of other options with your healthcare provider.

Summary

Antihistamine drug use is common, with medications like Claritin and Benadryl used to relieve allergy and cold symptoms, improve sleep, reduce nausea and vomiting, and more. Yet pregnant people may need to be more cautious about antihistamine use.

Study results on antihistamines and birth defects remain inconclusive, but there's general consensus that their use should be avoided during the first trimester of pregnancy. Decongestants should be avoided, too, and second-generation antihistamines may pose less risk.

Talk to your healthcare provider to discuss your options before taking an antihistamine while pregnant.