Antihistamines in Pregnancy: Safe Options and What to Avoid

When you're pregnant and your nose is constantly stuffed up, your eyes are itchy, or you're breaking out in hives, it’s hard to focus on anything else. Allergies don’t take a break just because you’re expecting-but neither can you safely reach for any over-the-counter pill without knowing the risks. So what antihistamines are actually safe during pregnancy? And which ones should you avoid?

Why This Matters More Than You Think

Uncontrolled allergies during pregnancy aren’t just annoying-they can make it harder to sleep, eat, or breathe. Severe rhinitis can lead to sinus infections, worsen asthma, and even affect your mood and energy. That’s why treating symptoms isn’t optional-it’s part of taking care of both you and your baby. But not all antihistamines are created equal. Some have decades of safety data. Others have very little. And some carry risks you need to know about before taking even one pill.

First-Generation vs. Second-Generation: The Big Difference

Antihistamines fall into two main groups: first-generation and second-generation. The difference isn’t just about how strong they are-it’s about how they affect your body.

First-generation antihistamines like chlorpheniramine, diphenhydramine (Benadryl), and dexchlorpheniramine cross the blood-brain barrier. That’s why they make you sleepy. But that same property means they’ve been around for a long time-since the 1940s and 50s-and have been used by millions of pregnant women. Studies tracking these drugs show no clear link to birth defects. The American College of Obstetricians and Gynecologists (ACOG) and the American Academy of Family Physicians (AAFP) both list chlorpheniramine as a safe, first-choice option during pregnancy.

Second-generation antihistamines like loratadine (Claritin), cetirizine (Zyrtec), and fexofenadine (Allegra) were designed to avoid the brain. That means less drowsiness. But because they’re newer, there’s less long-term data on their use in pregnancy. Still, the best studies we have-like those from the CDC’s National Birth Defects Prevention Study and reviews in the Journal of Skin Appendage Disorders-don’t show a clear increase in birth defects. ACOG’s March 2025 guidance says these newer options “may also be safe.”

The Safest Choices: What Experts Recommend

When it comes to choosing an antihistamine during pregnancy, three names come up again and again in medical guidelines:

• Chlorpheniramine (ChlorTrimeton) - First-gen, proven safe over decades, but causes drowsiness. Often used at 4 mg every 4-6 hours as needed.
• Loratadine (Claritin, Alavert) - Second-gen, non-sedating, widely studied. Recommended by Mayo Clinic and ACOG for mild symptoms. Typical dose: 10 mg once daily.
• Cetirizine (Zyrtec) - Also second-gen, minimal sedation in most people. Large studies show no increased risk of major birth defects. Dose: 10 mg once daily.

These three are the most commonly recommended by doctors. If you need something for occasional sneezing or itchy eyes, start here. Avoid anything else unless your doctor specifically says it’s okay.

What to Skip: The Risky Ones

Not all allergy meds are safe-even if they’re sold over the counter. Some ingredients carry known risks.

Pseudoephedrine (Sudafed) is the biggest red flag. It’s a decongestant often paired with antihistamines in cold and allergy formulas. ACOG warns against using it during the first trimester because of a small but real risk of abdominal wall defects like gastroschisis. Mayo Clinic says it might be okay in the second and third trimesters if you don’t have high blood pressure-but only under a doctor’s supervision. Always check the label. If it says “Sinus,” “Cold,” or “Multi-Symptom,” it likely contains pseudoephedrine.

Hydroxyzine (Atarax, Vistaril) is another one to avoid unless absolutely necessary. Some studies have linked it to a possible increase in certain heart defects, though the data is based on very few cases. It’s not banned, but it’s not first-line either.

And don’t assume natural remedies are safer. Some herbal supplements, essential oils, or homeopathic products can be just as risky-or worse-because they’re not tested in pregnancy. Always talk to your provider before trying anything new.

When to Use Nasal Sprays Instead

If your main problem is a stuffy nose, oral antihistamines might not be enough. That’s where nasal corticosteroids come in.

Medications like budesonide (Rhinocort), fluticasone (Flonase), and mometasone (Nasonex) are sprayed directly into the nose. They work locally, so very little enters your bloodstream. The AAFP gives them a safety rating of B-the same as chlorpheniramine and loratadine. Experts at Mayo Clinic recommend them for moderate to severe allergy symptoms, even during the first trimester.

They’re often more effective than pills for nasal congestion and don’t cause drowsiness. Many women find they need less oral medication-or none at all-when using a steroid spray regularly.

How to Decide What’s Right for You

There’s no one-size-fits-all answer. Your choice depends on your symptoms, your trimester, and your personal health history.

• Mild symptoms (sneezing, itchy eyes): Start with loratadine or cetirizine. They’re non-sedating and have strong safety data.
• Severe congestion: Add a nasal steroid spray like fluticasone. You can use both together safely.
• Need something fast for hives or sudden reactions: Chlorpheniramine works well, but plan for drowsiness. Take it at night if you can.
• Already taking something that works: Don’t switch unless your doctor advises it. Stability matters in pregnancy.

Never start or stop a medication based on internet advice. Even if it’s “natural” or “over-the-counter,” it can affect your baby. Always check with your OB-GYN or allergist first.

What the Research Still Doesn’t Know

We have good data on chlorpheniramine, loratadine, and cetirizine. But what about newer options like levocetirizine or desloratadine? There’s almost nothing. And what about long-term effects on children? Do they have higher rates of learning delays or behavioral issues? We don’t know yet.

The CDC’s National Birth Defects Prevention Study is still tracking antihistamine use from conception through birth. Some studies have found odd associations-like a possible link between hydroxyzine and heart defects-but the numbers are too small to be certain. That’s why experts say “reassuring,” not “proven safe.”

That’s why the bottom line isn’t about finding a perfect pill. It’s about finding the safest option for your situation-and using the lowest dose for the shortest time needed.

What to Do Next

If you’re pregnant and dealing with allergies:

1. Don’t suffer in silence. Untreated allergies can hurt your sleep, your mood, and your health.
2. Check the labels. Avoid products with pseudoephedrine, phenylephrine, or unknown herbal ingredients.
3. Start with the safest options: loratadine, cetirizine, or chlorpheniramine.
4. Consider a nasal steroid spray if congestion is your main issue.
5. Call your OB-GYN before taking anything new-even if it’s “just an allergy pill.”

Most women who take these medications during pregnancy have healthy babies. The goal isn’t to avoid all meds-it’s to use the right ones wisely. You’re not being reckless by treating your allergies. You’re being responsible.