Allergy Immunotherapy During Pregnancy
Yes, you can continue allergy shots if you are already on maintenance therapy, but you should not start allergy shots for the first time during pregnancy. 1
Key Recommendations
If Already on Maintenance Immunotherapy
Continue your current maintenance dose without increasing it. 1 The most recent 2024 American Academy of Otolaryngology guideline confirms that allergen immunotherapy (both subcutaneous and sublingual) can be safely continued in women already on maintenance dosing before pregnancy. 1
- Do not increase your dose during pregnancy - maintain the same dose you were receiving when you became pregnant. 1
- Retrospective studies show no increased risk of prematurity, congenital malformations, hypertension/proteinuria, or perinatal deaths in women who continued immunotherapy during pregnancy. 1
- Both subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) appear safe to continue. 1, 2
If in Build-Up Phase When Pregnancy Occurs
Consider discontinuing immunotherapy if you are still in the build-up phase and not yet at a therapeutic dose. 1 The risk-benefit ratio is less favorable when you haven't reached maintenance dosing, as you're not yet receiving therapeutic benefit but still face the risk of systemic reactions.
Do Not Initiate During Pregnancy
Do not start allergy immunotherapy for the first time during pregnancy. 1 This is a firm contraindication based on the 2024 guideline from the American Academy of Otolaryngology. 1
- The concern is the potential for systemic allergic reactions and their treatment effects on the fetus, including spontaneous abortion, premature labor, or fetal hypoxia. 1
- While small studies (totaling only 62 women) showed no complications when immunotherapy was initiated during pregnancy, this evidence is insufficient to establish safety. 1, 2
The One Exception
The only scenario where initiating immunotherapy during pregnancy might be considered is for life-threatening Hymenoptera (bee/wasp sting) anaphylaxis. 1 In this high-risk situation, the benefit of preventing potentially fatal anaphylaxis may outweigh the risks of starting immunotherapy.
Important Safety Considerations
Enhanced Precautions Required
Strict adherence to safety protocols is critical during pregnancy because systemic reactions could affect both you and your fetus. 1
- Ensure you wait the full observation period (typically 30 minutes) after each injection. 1
- Report any symptoms immediately to your healthcare provider. 1
- Always have injectable epinephrine available. 1
Reassuring Safety Data
The available evidence, though limited to retrospective studies, is consistently reassuring. 1, 2 Studies examining over 400 pregnancies found that women who continued immunotherapy actually had lower rates of complications compared to those who discontinued, though this may reflect selection bias. 1
No Evidence of Fetal Harm
Among the few pregnant women who experienced generalized allergic reactions while receiving immunotherapy, none had fetal complications. 2 Additionally, immunotherapy during pregnancy does not appear to alter the risk of developing allergic disease in offspring. 2
Clinical Reasoning
The distinction between continuation and initiation reflects a fundamental risk-benefit calculation: 1
- Continuation: You're already tolerating the allergen dose, receiving therapeutic benefit, and at lower risk of severe reactions on stable maintenance dosing.
- Initiation: You face the highest risk period (build-up phase) without yet receiving benefit, making the risk-benefit ratio unfavorable during pregnancy.
This approach prioritizes maternal and fetal safety while allowing women who are already benefiting from immunotherapy to continue their treatment. 1