- Few drugs are tested on pregnant women because of the potential risk to the fetus, so it's virtually impossible to say that any allergy medications are completely risk-free. Most of the evidence for drug safety comes from tests on pregnant animals.
- If possible, avoid all allergy medications during the first trimester, when the fetus is developing vital organs. If you're in your first trimester and your allergies are making you miserable, speak with your doctor about the safest forms of relief.
- From the second trimester on, Benadryl, ChlorTrimeton, and Actifed are considered safe medications, according to BabyCenter.
- Allergy shots are generally considered safe if you started receiving them before becoming pregnant; Since you'll be taking them under a doctor's supervision, tell your doctor as soon as you find out you're pregnant.
- The active ingredient diphenhydramine, found in Benadryl, may bring on pre-term labor if taken in the third trimester, although it does not directly harm the fetus, according to Harvard Medical School.
