Allergies and pregnancy: myths and reality

Pregnancy for many women is not only a long-awaited joy, but also a cause for alarm. The information space is replete with articles on a variety of risk factors. Some of which really require attention, while others are nothing more than a myth.

The “danger” of an allergy in a pregnant woman for the health of the fetus is one of the common reasons for concern. How justified is the concern? Understanding.

Myth number 1: exacerbation of allergies during pregnancy – the risk of “allergization” of the child
The mechanism of development of an allergic reaction is identical to that of any inflammation. Foreign object – production of antibodies – binding, elimination and destruction of antigen – recovery.

In the case of allergies, such “protection” are antibodies of class E, and a foreign object – some elements of the environment or food. Produced by the body after the first encounter with an “unpleasant” object, IgE are stored in the blood as “memory” cells and instantly initiate an “attack” (release of histamine and the like) upon a second encounter with an allergen.

However, due to their large size, class E antibodies are not able to penetrate the placental barrier, and the point of application of histamine and similar substances is only the “target” tissues of the allergic person (skin, respiratory tract and conjunctiva). Thus, neither IgE, nor the “products” of its activity are capable of exerting any serious influence on the fetus.

Myth number 2: pregnancy provokes an exacerbation of allergies
Pregnancy is known for some “muffled” immune processes. Without a relative decrease in the protective forces, the fetus would be rejected as a foreign object, but thanks to the hormones of the adrenal glands, this does not happen.

Normally, the level of cortisol in a pregnant woman remains elevated until delivery. This weakens the reactivity of her immunity, not only in relation to microorganisms, but also allergens, allowing her to “rest” from the unpleasant symptoms of allergies.

However, in about 10-30% of expectant mothers, allergies still make themselves felt. This can be due to a number of reasons, including genetic characteristics of the immune and hormonal status.

Myth number 3: a blood test can predict a probable allergy
A blood test for general immunoglobulin E serves to confirm the allergenic nature of existing symptoms and cannot be a risk marker.

Allergy skin tests can help predict the development of an allergic reaction in advance. The study involves the application of allergens to a previously “scratched” area of ​​the skin with a further assessment of the reaction. True, skin tests during pregnancy are not recommended, and the tests themselves can be false negative, due to the “work” of cortisol. Whereas a blood test for class E antibodies to a specific allergen has no contraindications, and the high sensitivity of the test allows you to detect even the smallest changes. The level of immunoglobulin E to the allergen indicates the level of “sensitization” – the possible sensitivity of the body to the allergen.

I must say that to confirm the diagnosis in combination with IgE, a general blood test with a leukocyte formula (attention to eosinophils) and eosinophilic cationic protein (with hay fever) are shown.

Obtaining increased values ​​in the results is a rationale for further examination, aimed either at finding a direct individual allergen, or identifying a reaction to a specific group.

It is worth noting that the presence of allergies for some becomes a “surprise”, since in a mild form the symptoms may be no different from skin diseases, ARVI and even food intolerance. And due to the complex structure of some allergens, hypersensitivity, for example, to birch, is manifested by a reaction when eating peaches.

Thus, allergy as such is not capable of harming the fetus, normally should not appear during pregnancy, it is not possible to predict its appearance, and a simple and effective blood test can help to find out the reactivity already present.