What are the safety considerations for using antihistamines (anti-histamine medications) during pregnancy?

From the Guidelines

The use of second-generation antihistamines, such as loratadine or cetirizine, is considered safe during pregnancy, with no significant increase in congenital malformations when used during the first trimester, as confirmed by large birth registries, case-control studies, and cohort studies 1. When considering the safety of antihistamines during pregnancy, it's essential to weigh the benefits and risks.

• The first trimester is the most critical period for concern about potential congenital malformations due to medication use, as organogenesis is occurring 1.
• First-generation antihistamines, such as chlorpheniramine, have been recommended as first-choice agents due to their observed safety and longevity of use, but their sedative qualities and possible effect on performance may make them less desirable choices 1.
• Second-generation antihistamines have excellent safety records and do not show a significant increase in congenital malformations when used during the first trimester, making them a preferred option 1.
• However, caution is still advised for a few antihistamines, such as diphenhydramine, which has been associated with cleft palate in some case-control studies, and hydroxyzine, which should be used cautiously during the first trimester based on animal data 1.
• Non-medication approaches, such as avoiding allergen triggers, using saline nasal sprays, and keeping indoor air clean, should be tried first to manage allergy symptoms during pregnancy.
• If medication is necessary, it's crucial to consult with a healthcare provider to determine the best course of treatment, as individual health circumstances may affect recommendations.

From the FDA Drug Label

If pregnant or breast-feeding, ask a healthcare professional before use The safety considerations for using antihistamines, such as diphenhydramine, during pregnancy include:

• Consulting a healthcare professional before use, as indicated on the drug label 2 It is recommended to exercise caution and consult a healthcare professional before using antihistamines during pregnancy, as the label advises asking a healthcare professional before use.

From the Research

Safety Considerations for Antihistamine Use During Pregnancy

• Antihistamines may be used during pregnancy for the treatment of allergic rhinitis, upper respiratory infections, urticaria/angioedema, atopic dermatitis, and anaphylaxis 3
• The use of H1 antihistamines during pregnancy is generally considered safe, with no increased risk of major malformation or other adverse fetal outcomes 4
• Second-generation antihistamines, such as cetirizine and loratadine, are considered safe to use during pregnancy, while first-generation antihistamines may have sedative properties 5, 6
• Medications to avoid during pregnancy include intranasal antihistamines, first-generation antihistamines (except for those considered safe), mycophenolate mofetil, methotrexate, cyclosporine, azathioprine, and zilueton 5, 6
• Every drug used in pregnancy carries a risk for teratogenicity, and careful risk/benefit assessment should be done before prescribing them 7
• Treatment during pregnancy should be precise and safe for the fetus, with consideration of the clinical data and proper monitoring 6

Specific Antihistamines and Their Safety During Pregnancy

• Cetirizine and loratadine are considered safe to use during pregnancy 5, 6
• First-generation antihistamines may have sedative properties, but are considered safe to use during pregnancy 6
• Intranasal antihistamines should be avoided during pregnancy 5
• Other antihistamines, such as leukotriene receptor antagonists, may be safe to use during pregnancy, but require further study 5

General Guidelines for Antihistamine Use During Pregnancy

• Antihistamines should only be used during pregnancy when the benefits outweigh the risks 3, 7
• Pregnancy-appropriate regimens should be discussed with all women of childbearing age as part of the informed therapeutic decision-making process 3
• Treatment during pregnancy should be precise and safe for the fetus, with consideration of the clinical data and proper monitoring 6