The effects of pregnancy on asthma have been extensively studied. However, they vary from one individual to another. The following is the rough estimate of the outcome.
- 1/3: Asthma worsens
- 1/3: Asthma does not change
- 1/3: Asthma improves.
The pattern present during the first pregnancy tends to repeat itself during the subsequent ones.
The allergy drugs are classified (see below) according to their tumor-producing effects on the fetus.
| CATEGORY | ANIMAL STUDIES | HUMAN STUDIES |
| A | Negative | Negative |
| B | Positive | Negative |
| C | Positive | Not done |
| D | Positive | Positive |
During pregnancy, the category A and B are preferred. The C drugs can be used if A and B drugs are not adequate for treatment and the potential benefits outweigh the risks.
Listed below are the classifications of commonly used allergy medicines
| B | C | |
| Steroid inhalers | Pulmicort | Vanceril, Azmacort, Flovent |
| Oral steroids | Prednisone, Medral | |
| Anti-leukotrienes | Singulair, Accolate | |
| Bronchodilators | Brethine, Atrovent | Proventil, Albuterol, Ventolin, Serevent. Foradil, Slo- Bid, Theo-Dur |
| Combination drugs | Advair | |
| Antihistamines | Benedryl, Chlortrimeton, Claritin, Zyrtec | Atarax, Allegra, Clarinex |
