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Allergies in pregnant women
Last reviewed: 04.07.2025

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Statistics show that allergies are diagnosed quite often in pregnant women – almost every fourth woman expecting a baby suffers from some form of allergy. Signs of an allergic reaction in pregnant women are not much different from the symptoms of allergies in other people, but the disease is more complicated in expectant mothers.
Allergy is most often not a direct contraindication to conception and the process of bearing a fetus, despite the risk of transmitting an allergic reaction by inheritance. However, there are a number of difficulties and threats that must be taken into account by both the expectant mother and her attending physician.
Why do allergies develop in pregnant women?
It should be noted that the risk group mainly includes those women who already had a predisposition to allergies before conception; other pregnant women most often suffer from false allergies, that is, either intolerance to a product, or the so-called allergy to the fact of pregnancy itself.
Any allergen that provokes an aggressive response of the immune system can cause an allergy in the expectant mother. This includes pollen and household dust, hair or dander of domestic animals, in a word, the entire standard list of allergens. Also, the body of a pregnant woman is extremely susceptible to various food provocateurs. Considering the taste "whims" and possible uncontrolled consumption of the desired product, we can confidently say that food allergies are provoked not so much by the product itself, but by its quantity. There is also a version about the influence of hormonal changes on the body's sensitivity to allergens. Thus, the very fact of pregnancy becomes a provoking factor for the occurrence of an allergic reaction. This theory has not yet been statistically confirmed by the international allergological community, but is also not denied by allergists.
How does allergy manifest itself in pregnant women?
Clinical manifestations of allergies in pregnant women are almost identical to the symptoms of a classic allergic reaction. However, it has been noted that most often expectant mothers suffer from rhinitis, which is also called vasomotor rhinitis of pregnancy. This symptom is associated with hormonal changes in the woman's body, which are most clearly manifested in the second trimester. The second on the list of allergic symptoms is dermatitis or urticaria. Severe itching certainly complicates the condition of the expectant mother, but is not such a threatening symptom as bronchial asthma, which can also develop during pregnancy. Asthma most often does not debut during the period of bearing a child, it can recur, having begun long before conception. According to the observations of gynecologists, bronchial asthma during pregnancy, if it manifests itself, is much easier and less often than before. This is due to the fact that the level of cortisol in the woman's body increases significantly, which can "inhibit" allergic reactions. As with all allergy sufferers, the most dangerous allergic manifestations are considered to be generalized urticaria, Quincke's edema and anaphylactic shock. Of course, these formidable manifestations of allergy will not be able to develop if the pregnant woman is attentive to the slightest changes and reactions to various irritants. Most often, both Quincke's edema and anaphylactic shock can be prevented in the early stages of development.
Why are allergies dangerous for pregnant women?
If a pregnant woman is attacked by an allergy, this usually does not affect the intrauterine development of the fetus, since the baby is reliably protected by the mother's placenta. Only two main factors that must be taken into account can affect the condition of the fetus:
- Constant shortness of breath, difficulty breathing and, especially, attacks of bronchial asthma in the mother can affect the condition of the fetus (hypoxia).
- Medicinal anti-allergic therapy prescribed for vital indications can affect uteroplacental blood flow and cause some intrauterine defects.
Allergy in pregnant women is not a serious pathology that threatens the baby, since maternal immune complexes that respond to the invasion of an antigen are not able to penetrate the placenta. However, even a small share of risk requires preventive measures, which include the following recommendations.
How are allergies treated in pregnant women?
If the expectant mother is careful enough, the use of drugs can be reduced to a minimum, because many antihistamines are strictly contraindicated during pregnancy. It is strictly forbidden to take diphenhydramine and all drugs that contain it. Diphenhydramine can increase the tone of the uterus and provoke a miscarriage. There are drugs that can affect the intrauterine development of the fetus, so the prescription of antihistamines is the prerogative of the doctor and any medication is indicated only in the case when the result of treatment will be more valuable than the risk, that is, strictly lifelong indications. For skin manifestations of allergies - itching, redness, rashes, local antihistamines (ointments, gels, sprays) are allowed, but they must also be prescribed by a doctor. Advice from friends, recommendations from relatives, in a word, any self-medication during pregnancy is unacceptable.
Allergies in pregnant women, provided that the allergen is identified, are treated by eliminating the provoking substance. If it is household dust, then sometimes it is enough to remove all carpets, soft toys, do a general cleaning, ventilate the premises and provide adequate humidity so that the allergy symptoms simply disappear. Animals, plant pollen, other allergens - contact with them should be either excluded for the entire period of pregnancy or minimized. A hypoallergenic diet is also recommended, which in principle should become fundamental even in the absence of signs of allergy. If allergies in pregnant women develop and require drug treatment, the latest generation of antihistamines are usually prescribed, which have minimal side effects on both the mother's body and the fetus.
How to prevent allergies during pregnancy?
Hypoallergenic diet and reasonable portions of desired, preferred products. It has long been known that the digestive tract of the expectant mother is the main source of allergies, especially at 20-22 weeks of pregnancy, when the immune system of the fetus is already quite well formed. Any product that the pregnant woman is “drawn to” should be consumed in small portions so as not to provoke a food allergy in the woman and a possible aggressive immune response in the baby in the future. In addition, all allergy-provoking dishes should be excluded from the menu.
If possible, eliminate all provoking factors in the room - carpets, woolen blankets and rugs, in a word, everything where dust allergens can accumulate. The same applies to pets and flowering indoor plants. If they cannot be removed, contact with them should be limited as much as possible, at least during pregnancy.
Regular ventilation, wet cleaning and basic hygiene, but without the use of aggressive chemicals, will help significantly reduce the risk of allergies caused by household dust.
It is necessary to consult with the attending physician and start taking vitamins that help reduce allergic reactions. Such means include vitamins A, B, C.
Ascorbic acid is usually taken 1-3 grams per day - this helps strengthen the immune system and prevent the occurrence of vasomotor rhinitis. The dosage should be agreed with the doctor.
B vitamins, especially B12, are a kind of natural antihistamines. Cyanocobalamin significantly reduces the manifestations of skin allergic reactions, helps prevent attacks of bronchial asthma. The dose is 500 mg per day, the course is from 3 to 4 weeks. The use of B vitamins should also be agreed with a gynecologist.
Taking zinc aspartate will help reduce the risk of allergies to odors, or more precisely, to household chemicals or cosmetics. Zinc should be taken only in complex compounds, so as not to provoke an imbalance of other important microelements - copper, iron.
All products containing fish oil or linoleic acid can prevent allergic rhinitis and itching.
Oleic acid will help neutralize excess histamine release, and it is found in refined, high-quality olive oil.
Taking pantothenic acid reduces the symptoms of vasomotor rhinitis well. Taking 100 milligrams before bedtime already gives a positive result on the second day.
Allergies in pregnant women may not manifest themselves if future mothers give up bad habits, follow such simple and familiar principles of a healthy lifestyle and are ready for positive changes in their lives.