Antihistamines in Pregnancy: What’s Safe and What to Avoid

When you're pregnant and your nose is stuffed up, your eyes are itchy, and your skin is breaking out in hives, the last thing you want is to suffer through it. But the moment you reach for that bottle of Benadryl or Claritin, a question pops up: is this safe for my baby? You're not alone. Millions of pregnant women deal with allergies each year, and the fear of harming the baby often keeps them from treating symptoms that are already making life harder.

Why Antihistamines Even Matter During Pregnancy

Allergies don’t take a break just because you’re pregnant. In fact, about 20% of pregnant women report worsening allergy symptoms. Runny nose, sneezing, itchy eyes - these aren’t just annoying. They can disrupt sleep, make it hard to eat, and even trigger asthma flare-ups. Uncontrolled allergic rhinitis increases the risk of sinus infections and can make you more prone to respiratory issues. That’s not just uncomfortable - it can affect how much oxygen you and your baby get.

So, the real question isn’t whether you should take something. It’s: which thing? Not all antihistamines are the same. Some have decades of use behind them. Others are newer, with less data. And some? You should avoid them entirely.

First-Generation Antihistamines: The Old Standbys

These are the antihistamines that make you sleepy. That’s because they cross the blood-brain barrier. Common ones include:

• Chlorpheniramine (Chlor-Trimeton)
• Diphenhydramine (Benadryl)
• Dexchlorpheniramine
• Triprolidine

They’ve been around since the 1940s and 50s. That means doctors have seen how they affect pregnancies over generations. Studies tracking thousands of pregnancies show no consistent link between these drugs and birth defects. The American College of Obstetricians and Gynecologists (ACOG) and the American Academy of Family Physicians (AAFP) both list chlorpheniramine as a safe option. The CDC’s National Birth Defects Prevention Study, which looked at over 14 different antihistamines, found no major red flags for these older drugs.

But here’s the catch: drowsiness. If you’re already exhausted from pregnancy, adding a sedating antihistamine might help you sleep - but it can also make you too groggy to drive, care for other kids, or focus at work. Some women report feeling foggy all day. That’s not worth it unless the allergy symptoms are severe.

Second-Generation Antihistamines: The Non-Sedating Options

These are the ones you see advertised on TV: Claritin, Zyrtec, Allegra. They don’t cross into your brain as easily, so they don’t make you drowsy. That’s a big plus. The main ones are:

• Loratadine (Claritin, Alavert)
• Cetirizine (Zyrtec)
• Fexofenadine (Allegra)
• Levocetirizine (Xyzal)

Loratadine and cetirizine are the most studied in pregnancy. A 2022 CDC analysis of data from over 1,500 pregnant women taking loratadine found no increase in major birth defects. Cetirizine has similar results. The Mayo Clinic and ACOG both say these are safe choices - even in the first trimester. That’s important. The first trimester is when organs form, and that’s when most people worry the most.

Fexofenadine has less data, but what’s there doesn’t raise alarms. Levocetirizine and desloratadine are newer and even less studied, so they’re not usually the first pick unless the others don’t work.

What About Nasal Sprays?

Sometimes, pills aren’t enough. If you’ve got constant congestion, a steroid nasal spray might be a better choice. And guess what? These are often safer than oral meds.

• Budesonide (Rhinocort Allergy)
• Fluticasone (Flonase Allergy Relief)
• Mometasone (Nasonex 24HR Allergy)

These sprays work locally. Very little of the drug gets into your bloodstream, so even less reaches the baby. ACOG and AAFP both rate them as safe for use in all three trimesters. Many OB-GYNs recommend starting with a steroid spray for moderate to severe nasal symptoms - and only adding an antihistamine if you still need it.

The Big No-No: Pseudoephedrine

Don’t confuse antihistamines with decongestants. Pseudoephedrine (Sudafed) is a common ingredient in allergy and cold meds. It’s not an antihistamine - it’s a stimulant. And it’s risky in early pregnancy.

The ACOG warns against using pseudoephedrine during the first 12 weeks. Studies link it to a small but real increase in abdominal wall defects like gastroschisis. If you’ve got a stuffy nose, don’t reach for a combo product that says “allergy + decongestant.” Read the label. If it has pseudoephedrine or phenylephrine, skip it.

After the first trimester, pseudoephedrine might be okay in low doses (30-60 mg every 4-6 hours, max 240 mg/day) - but only if you don’t have high blood pressure. Even then, it’s not the first choice. Stick to saline sprays or steroid nasal sprays instead.

What About Hydroxyzine?

Hydroxyzine (Atarax, Vistaril) is sometimes prescribed for itching or anxiety during pregnancy. It’s a first-generation antihistamine, but it’s not the same as chlorpheniramine. Some studies have linked it to a possible increased risk of conotruncal heart defects - but the numbers are tiny. Only seven cases were reported in a study of over 1,500 exposures. That’s not enough to prove it causes harm, but it’s enough to make doctors cautious.

Most OB-GYNs avoid hydroxyzine unless there’s no other option - like for severe, treatment-resistant itching. If you’re prescribed it, ask why. Make sure your doctor knows you’re pregnant.

What’s the Bottom Line?

Here’s what the evidence says, plain and simple:

• Best first-choice oral antihistamines: Loratadine (Claritin) and cetirizine (Zyrtec)
• Safe older option: Chlorpheniramine (if you don’t mind being sleepy)
• Best for nasal symptoms: Budesonide, fluticasone, or mometasone nasal sprays
• Avoid: Pseudoephedrine in the first trimester, hydroxyzine unless absolutely necessary

The goal isn’t to eliminate all symptoms. It’s to find the lowest effective dose that keeps you comfortable without risking the baby. Take only what you need. Don’t double up on meds. And never take something just because it’s “over the counter.”

What If Your Allergies Are Really Bad?

If you’re struggling to breathe, sleep, or eat because of allergies, don’t suffer. Untreated asthma or severe rhinitis can lead to preterm labor, low birth weight, or preeclampsia. That’s a real risk.

Talk to your OB-GYN or an allergist. They might recommend:

• Combining a steroid nasal spray with loratadine
• Using a saline rinse (neti pot) daily
• Trying allergen avoidance - like washing bedding weekly, using HEPA filters, keeping windows closed during pollen season

Sometimes, the best treatment isn’t a pill. It’s a change in environment.

When to Call Your Doctor

You don’t need to panic over every sneeze. But call your provider if:

• You’re using antihistamines daily for more than a few weeks
• Your symptoms are getting worse, not better
• You’re considering a new medication you haven’t used before
• You’ve taken something without checking with your doctor

There’s no shame in asking. Every pregnancy is different. What’s safe for one person might not be right for another.

What About Natural Remedies?

Honey, saline rinses, air purifiers - these are fine. They’re low-risk and often helpful. But don’t assume “natural” means safe. Some herbal supplements can be dangerous in pregnancy. Butterbur, for example, is sometimes used for allergies - but it’s linked to liver damage and birth defects in animal studies. Avoid it.

Stick to what’s been tested: saline, steam, humidity, and proven medications.

Final Thoughts

You’re not being reckless for wanting relief. Allergies during pregnancy are real, and they matter. The goal isn’t to avoid all meds - it’s to use the right ones, at the right dose, for the right reason. Loratadine and cetirizine are your safest bets. Steroid nasal sprays are often better than pills. Avoid decongestants early on. And always check with your doctor before starting anything new.

Your health affects your baby’s. Treating your allergies isn’t selfish - it’s responsible.