Safety of Diphenhydramine During Pregnancy
Safety Profile and Risks
- The American College of Allergy, Asthma, and Immunology recommends that diphenhydramine should be used with caution during pregnancy, particularly in the first trimester, due to concerns about a possible association with cleft palate, although recent studies have not conclusively confirmed this risk 1, 2
- Both first-generation and second-generation antihistamines generally have good safety records during pregnancy, but specific concerns exist for diphenhydramine 1, 2
- Although diphenhydramine is frequently used during pregnancy, there is some concern over a case-control study suggesting an association with cleft palate that has not been sufficiently refuted 2
- The most critical time for concern about potential congenital malformations is the first trimester, when organogenesis occurs 2
Evidence Quality and Recommendations
- Recent studies have not detected significant increased risk for congenital malformations with diphenhydramine use during pregnancy, but caution is still advised 2
Alternative Antihistamine Options
- Chlorpheniramine has been recommended as a first-choice antihistamine during pregnancy due to its observed safety and longevity of use 3
- Cetirizine and loratadine (FDA Pregnancy Category B drugs) have more accumulated safety data than some other antihistamines and may be preferred options 3
- Second-generation antihistamines have confirmed safety through large birth registries, case-control studies, and cohort studies 2
Clinical Approach to Antihistamine Use in Pregnancy
- When antihistamine treatment is necessary during pregnancy, consider using antihistamines with better documented safety profiles (chlorphenamine, cetirizine, or loratadine) over diphenhydramine 3
- If diphenhydramine is used, avoid first trimester if possible 1, 2
Common Pitfalls and Considerations
- Combining antihistamines with oral decongestants should be avoided during the first trimester due to potential risks 1
- Assuming all antihistamines have equivalent safety profiles during pregnancy is incorrect 3