From the Guidelines
Loratadine or cetirizine are the preferred antihistamines during pregnancy due to their extensive use and lack of association with increased risk of congenital anomalies. According to the European Respiratory Journal study 1, several studies have reported associations between specific H1-antihistamines in early pregnancy and certain birth defects, but in general, H1-antihistamines have not been linked to increased risk of congenital anomalies.
Key Considerations
- Loratadine and cetirizine are considered safe during pregnancy, with no increased risk of birth defects 1.
- First-generation antihistamines like diphenhydramine can also be used, but may cause drowsiness, making them more suitable for nighttime use.
- Antihistamine use during the last 2 weeks of pregnancy may be associated with retrolental fibroplasia in premature infants, although these findings have not been corroborated 1.
Recommended Dosage
- Loratadine: 10mg once daily
- Cetirizine: 10mg once daily
- Diphenhydramine: 25-50mg every 4-6 hours as needed, not exceeding 300mg daily ### Non-Medication Approaches
- Avoiding allergens
- Using saline nasal sprays
- Running an air purifier, especially during the first trimester when organ development is occurring It is essential to consult with a healthcare provider before starting any medication during pregnancy, as individual circumstances may affect recommendations 1.
From the FDA Drug Label
If pregnant or breast-feeding, ask a health professional before use. If pregnant or breast-feeding: if breast-feeding: not recommended if pregnant: ask a health professional before use. The FDA drug label does not answer the question.
From the Research
Antihistamines in Pregnancy
- The use of H-1-antihistamines during pregnancy has been controversial due to possible teratogenic effects of these drugs 2.
- None of the antihistamines available today have been categorized as safe during pregnancy, and control studies are available for certain first-generation drugs regarding their safety in pregnancy, but newer agents require further studies to be declared safer in pregnancy 2.
- A few drugs are comparatively safer to use in pregnancy than others, and every drug used in pregnancy carries a risk for teratogenicity, so careful risk/benefit assessment should be done before prescribing them 2.
Safety of H1 Antihistamines
- H1 antihistamines are not associated with an increased risk of major malformation or other adverse fetal outcomes, according to a systematic review and meta-analysis 3.
- The risk of major malformation in the offspring of women exposed to H1 antihistamines was not higher than that of the control population, and there was no evidence of publication bias 3.
- H1 antihistamines were not associated with more spontaneous abortions, prematurity, stillbirth, or low birth weight 3.
Comparison of Antihistamines
- Cetirizine, terfenadine, loratadine, astemizole, and chlorpheniramine have different suppressive effects on histamine-induced wheals and flares, with cetirizine being the most effective 4.
- Newer-generation antihistamines, such as desloratadine, cetirizine, and fexofenadine, are effective at managing the symptoms of seasonal allergic rhinitis, but cetirizine is more likely to cause sedation 5.
- A comparative study of apo-cetirizine single therapy and intermittent sequential therapy with cetirizine, loratadine, and chlorpheniramine in allergic rhinitis showed that combination therapy was better in improvement of nasal congestion, but the difference was not statistically significant 6.