Most, but not all, research suggests antihistamines are safe to take during pregnancy. Doctors often recommend second-generation, non-sedative antihistamines.

Antihistamines are a group of medications most frequently used to relieve allergy symptoms. They’re sometimes also used for other conditions, such as reducing nausea and vomiting.

Most of the available research suggests that these medications aren’t linked to an increased risk of birth defects for pregnant people. However, it’s always a good idea to discuss their use with your healthcare professional before taking them, since some types have been linked to health problems in some studies.

Minimizing exposure to your allergy triggers while pregnant can help you minimize your need to take antihistamines unnecessarily.

Read on to learn about the safety of taking antihistamines while pregnant and about which types doctors usually recommend.

Researchers are continuing to examine the safety of various antihistamines in pregnant people. Currently, most evidence suggests that they’re safe, but some researchers have raised concerns.

In a 2020 study, researchers examined the use of antihistamines during early pregnancy to see if they were associated with birth defects. The researchers examined 41,148 pregnancies from 1997 to 2011. Approximately 13% of cases and controls were exposed to antihistamines in early pregnancy. The researchers found a lack of strong evidence that antihistamine use was associated with birth defects.

The researchers noted that these results were contrary to some previous studies that did find associations between birth defects and some antihistamines. For example, one study they cited found a potential relationship with antihistamines, such as:

  • diphenhydramine
  • loratadine
  • chlorpheniramine
  • doxylamine

To err on the side of caution, it’s likely best to speak with your doctor before taking antihistamines if you’re pregnant, since there has been a mix of results in various studies. It’s also likely that some medications are safer than others.

Potential link with liver cancer

In a 2024 study, researchers found that exposure to antihistamines in early pregnancy may increase the risk of liver cancer in adulthood.

Use for women with allergies and preeclampsia

In a 2022 study, researchers examined the use of antihistamines before or during pregnancy to prevent early onset preeclampsia in women with allergies. Preeclampsia is when you have new high blood pressure during pregnancy.

The researchers found that using antihistamines for allergies before the formation of the placenta was associated with a lower risk of early onset preeclampsia than using antihistamines used only in late pregnancy.

There are two main types of antihistamines, H-1 and H-2 antihistamines. H-1 antihistamines are generally used to treat allergies.

H-1 antihistamines are further divided into first- and second-generation. Second-generation antihistamines don’t cross the blood-brain barrier and are generally the ones doctors recommend during pregnancy. Specifically, doctors often recommend Ceririzine and loratadine since they’re non-sedative.

Common first-generation H-1 antihistamines used in the United States include:

Second-generation H-1 antihistamines include:

It’s always best to consult your doctor about what dose of your medication you should take. Your doctor may recommend taking a low dose to start and increasing your dose only if the medication isn’t effective.

It’s very important to avoid exceeding your doctor’s recommendations to avoid potential side effects or complications.

It’s important to check the active ingredients in any allergy medications you buy before you take them if you’re pregnant. In the United States, most common antihistamines are available without a prescription.

It’s best to always speak to your healthcare professional before starting to take antihistamines or other new medications while pregnant.

Zyrtec is generally considered safe during pregnancy. Research doesn’t suggest that fetuses have an increased risk of birth defects. Researchers haven’t examined whether it’s linked to learning disabilities or behavioral issues.

Non-sedating second-generation antihistamines are usually recommended for treating allergies in pregnant people. Ceririzine and loratadine are often considered the medications of choice.

Most of the currently available research suggests that antihistamines are safe to take for people who are pregnant. Some studies have raised concerns that they may be linked to birth defects, especially first-generation H-1 antihistamines.

It’s always best to speak with your doctor before starting to take antihistamines if you’re pregnant. Your doctor can best advise you on how much is safe to take and which type may be best for you.