Is Allegra safe during pregnancy?

What does the evidence say about Allegra during pregnancy?

1. Studies on fexofenadine so far haven't found a higher chance of birth defects, miscarriage, preterm birth, or low birth weight compared to other allergy medicines. 1
2. Fexofenadine passes into breast milk in only tiny amounts and isn't expected to cause problems for a nursing baby, though pairing it with a decongestant like pseudoephedrine, as in Allegra-D, may reduce milk supply. 2
3. A small 2026 study that directly compared fexofenadine with a newer allergy medicine found similarly low rates of major birth defects in both groups, though it only followed about 60 pregnancies total, so it's far from the final word. 3
4. Cetirizine (Zyrtec) has a deeper research base, over 1,300 studied pregnancies and counting, which is one reason some providers suggest trying it or loratadine before fexofenadine. 4
5. Loratadine (Claritin) is also considered one of the less sedating antihistamine options, so it's often reached for first alongside cetirizine, with fexofenadine kept as a backup choice. 5

Is Allegra safe in each trimester?

• First trimester. Fexofenadine hasn't shown a higher chance of birth defects in the studies published so far, and that data covers first-trimester exposure too. If you're only dealing with mild, occasional symptoms early on, it's still worth starting with a conversation with your provider before reaching for a new medication.
• Second trimester. Seasonal allergies and nasal congestion often get worse as pregnancy goes on, and fexofenadine's safety profile doesn't change in the second trimester. Since cetirizine and loratadine have more pregnancy research behind them, this is a good time to ask your provider whether one of those would work just as well for you.
• Third trimester. No specific third-trimester concern for the baby has turned up in the data. Fexofenadine does pass into breast milk in small amounts, so mention regular use at your later visits, especially if you're considering the '-D' decongestant version, which carries separate concerns.