Allergy Medications During Pregnancy: What’s Safe and What to Avoid

Managing allergies during pregnancy isn’t just about sneezing and itchy eyes-it’s about making smart choices that protect both you and your baby. About one in three pregnant people deal with allergic rhinitis, hives, or conjunctivitis, and many need medication to feel normal. But not all allergy drugs are created equal when you’re pregnant. Some are well-studied and safe. Others carry real, documented risks. Knowing the difference can mean the difference between relief and regret.

First Trimester: The Most Sensitive Time

The first 12 weeks of pregnancy are when your baby’s organs are forming. That’s why doctors urge caution with any medication during this time-even ones you’ve used for years. If your allergies are mild, start with non-drug options. Try saline nasal sprays, rinse your nose with a neti pot, use HEPA filters in your home, and keep windows closed during high pollen season. These aren’t just "natural" fixes-they’re proven, zero-risk strategies backed by the American College of Allergy, Asthma, and Immunology.

If symptoms are severe enough to disrupt sleep or daily function, talk to your provider before reaching for anything oral. Even then, the safest bets are nasal sprays that don’t enter your bloodstream much. Among them, Rhinocort (budesonide) stands out. It’s the most studied nasal steroid in pregnancy, with data from over 10,000 exposures showing no increase in birth defects. Flonase Sensimist (fluticasone furoate) and Nasonex (mometasone) are also considered safe. But avoid Nasacort (triamcinolone)-there’s just not enough data to say it’s safe.

Oral Antihistamines: First-Gen vs. Second-Gen

When nasal sprays aren’t enough, antihistamines come into play. There are two main types, and they’re not interchangeable.

First-generation antihistamines like diphenhydramine (Benadryl) and chlorpheniramine (Chlor-Trimeton) have been around since the 1940s. Thousands of pregnant women have taken them, and studies tracking over 200,000 pregnancies found no link to birth defects. The American Academy of Family Physicians confirms this safety record. But here’s the catch: they make you sleepy. A lot. If you’re already exhausted from pregnancy, adding drowsiness isn’t helpful. Still, for nighttime relief or severe itching from hives, they’re a solid option.

Second-generation antihistamines like cetirizine (Zyrtec), loratadine (Claritin), and fexofenadine (Allegra) are non-drowsy and more convenient. Zyrtec and Claritin have strong safety data from multiple studies, and are now routinely recommended after the first trimester. Fexofenadine is trickier. The FDA lists it as Pregnancy Category C, meaning animal studies showed no harm, but human data is limited. Still, no red flags have emerged in real-world use. Most allergists consider it safe if the others don’t work.

Watch out for combo products. Claritin-D, Zyrtec-D, or any pill with "-D" means it contains pseudoephedrine. That’s a red flag.

Pseudoephedrine: The Big No in Early Pregnancy

Decongestants are where things get dangerous. Pseudoephedrine (Sudafed) and phenylephrine are oral decongestants that narrow blood vessels-not just in your nose, but everywhere. That includes the placenta. A 2009 study in the American Journal of Obstetrics and Gynecology found that using pseudoephedrine in the first trimester raised the risk of gastroschisis-a rare but serious birth defect where the baby’s intestines develop outside the abdomen-by more than double.

That’s why the American College of Obstetricians and Gynecologists and the American Academy of Allergy, Asthma & Immunology both say: avoid it in the first 12 weeks. Even later in pregnancy, it’s not ideal. It can raise your blood pressure, which is risky if you have preeclampsia or gestational hypertension. Mayo Clinic updated its guidance in December 2023 to say that if you absolutely need it after the first trimester, you can use up to 30-60 mg every 4-6 hours, not exceeding 240 mg total per day. But even then, it’s a last resort.

And don’t think nasal sprays like Afrin (oxymetazoline) are safer. They’re not. They can cause rebound congestion and have no proven safety record in pregnancy. Use them for no more than three days if you must-but better yet, skip them.

What About Allergy Shots?

If you were already getting allergy shots before you got pregnant, you can usually keep going. The American College of Allergy, Asthma, and Immunology says continuing immunotherapy is safe and may even help reduce symptoms. But starting them during pregnancy? Don’t. The first few months of treatment carry a higher risk of allergic reactions, and your body is already under stress. Wait until after delivery to begin.

Asthma and Allergies: Don’t Ignore the Connection

About 8% of pregnant people have asthma, and uncontrolled asthma is far more dangerous to the baby than most asthma medications. Inhaled corticosteroids like fluticasone (Flovent), budesonide (Pulmicort), and mometasone (Asmanex) are considered safe throughout pregnancy. In fact, they’re often recommended because keeping your lungs open helps your baby get enough oxygen. Oral steroids like prednisone? Only use them if absolutely necessary and under close supervision. They’re not first-line during pregnancy.

Dosing and Formulations Matter More Than You Think

It’s not just about the drug-it’s about how you take it. Avoid extended-release (ER), sustained-release (SA), or multi-symptom formulas. These often combine antihistamines with decongestants or pain relievers you shouldn’t take. Stick to plain, single-ingredient tablets: 10 mg of loratadine once daily, 10 mg of cetirizine once daily, or 25-50 mg of diphenhydramine every 4-6 hours as needed.

Also, don’t assume "natural" or "herbal" means safe. Many herbal teas and supplements have no safety data in pregnancy. Some, like butterbur or echinacea, may even interfere with fetal development. Stick to what’s been studied.

What’s Changing in 2025?

The FDA stopped using the old A, B, C, D, X labels in 2018. Now, drug labels include detailed narratives about risks, benefits, and data sources. But many doctors still refer to the old system because it’s familiar. Expect this to change over time.

Right now, the biggest update coming is from the NIH’s Pregnancy Exposure Registry, which has tracked over 15,000 pregnant women taking allergy meds since 2018. Early data, expected in late 2024, could confirm whether newer antihistamines like desloratadine or levocetirizine are as safe as loratadine and cetirizine. The AAAAI plans to update its guidelines in Q2 2025 based on this.

For now, the message is clear: you don’t have to suffer. Safe options exist. But you need to be specific about what you take, when you take it, and why.

Bottom Line: You Have Options

You don’t have to suffer through allergy season while pregnant. The right medication, at the right time, can make a huge difference. Prioritize nasal steroids like Rhinocort or Flonase. Use Zyrtec or Claritin after the first trimester. Avoid anything with decongestants in the first 12 weeks. And always talk to your doctor before starting or stopping anything-even something you think is harmless.

Most importantly: your health matters. Untreated allergies can lead to poor sleep, stress, and even asthma flare-ups-all of which affect your baby. The goal isn’t to avoid all meds. It’s to choose the safest ones, for the shortest time, at the lowest effective dose. You’ve got this.