Safety of Antihistamines During Pregnancy

Introduction to Safety Concerns

The American Academy of Allergy, Asthma, and Immunology recommends using diphenhydramine with caution during pregnancy due to its association with potential risks, including cleft palate, though it has generally good overall safety data 1, 2, 3

The FDA classifies most antihistamines, including diphenhydramine, as Category B or C, indicating limited evidence of harm but incomplete safety data, according to the American College of Obstetricians and Gynecologists 3, 4
The general recommendation from the National Institute of Child Health and Human Development is to avoid all antihistamines if possible during pregnancy, especially in the first trimester 4

Administration of diphenhydramine during pregnancy has been associated with the development of cleft palate, which is a significant concern, as reported by the Centers for Disease Control and Prevention 1, 2, 3
While diphenhydramine has good overall safety data from historical use, this specific risk must be considered when evaluating treatment options, according to the American Academy of Pediatrics 3

Second-generation antihistamines may be preferable to first-generation antihistamines like diphenhydramine due to their safety profile, as suggested by the European Respiratory Society 1
Chlorphenamine is often chosen by clinicians when antihistamine therapy is necessary during pregnancy because of its long safety record, according to the Royal College of Obstetricians and Gynaecologists 4
Loratadine and cetirizine are classified as FDA Pregnancy Category B drugs, implying no evidence of harm to the fetus, although well-controlled human studies are limited, as reported by the FDA 4

Consider if antihistamine treatment is absolutely necessary, as avoiding medication during pregnancy is preferable when possible, according to the American College of Obstetricians and Gynecologists 4
If treatment is necessary, consider second-generation antihistamines before first-generation options like diphenhydramine, as recommended by the American Academy of Allergy, Asthma, and Immunology 1
Use the lowest effective dose for the shortest duration possible, as suggested by the National Institute of Child Health and Human Development, although the exact citation is not provided, a similar recommendation is made by the European Respiratory Society 5

No antihistamine has been proven completely safe during pregnancy, and all should be used with caution, as stated by the American Academy of Pediatrics 4
Always consider the risk of untreated maternal conditions against the potential risks of medication, as recommended by the European Respiratory Society 5