February 28, 2018

What Causes Anaphylaxis During Pregnancy?

Anaphylaxis is a life-threatening condition related to allergy. Allergic reactions, including anaphylaxis, occur when the cells in your immune system release a chemical known as histamine. An anaphylactic reaction can be triggered by various foods, medications, insect stings, or latex. Common signs of anaphylaxis include low blood pressure, urticaria and angioedema, asthma attack, nausea, vomiting, and diarrhea. Some women can also develop anaphylaxis during pregnancy.


It is more likely to happen during labor and delivery. Anaphylactic reaction is especially dangerous for the fetus, since it often leads to low blood pressure levels in the mother. Low blood pressure can block the blood flow to the brain, heart and other vital organs in the fetus. Anaphylaxis that occurs during pregnancy may also cause uterine cramps, vaginal and vulvar itching, and low back pain.

What Causes Anaphylaxis During Pregnancy?


Both pregnant and non-pregnant women may experience anaphylaxis as result of exposure to the same allergens. However, some allergy triggers are more likely to affect you during labor and delivery.

A review that involved 23 pregnant women with anaphylaxis showed that the majority of anaphylactic reactions were triggered by penicillin and similar antibiotics. Other causes included latex, insect stings and various medicines.

There is also a study that looked at 700,000 post-partum women in a Texas hospital. In 19 cases of anaphylaxis, which is about 0.0027% of deliveries, more than half of reactions were triggered by penicillin and other antibiotics. In most cases, anaphylaxis that happens during delivery requires cesarean section.

Why do penicillin and similar related antibiotics cause anaphylaxis during pregnancy? Penicillin and penicillin-related medicines are often given during labor and delivery in order to prevent infections, such as neonatal group B streptococcal (GBS), and as prophylaxis during cesarean section.

If you think you have a penicillin allergy, the best way to know for sure is to conduct skin allergy testing. However, allergy testing is not recommended in pregnant women due to the small risk of an anaphylactic reaction. In general, penicillin should be avoided during pregnancy – experts recommend replacing it with alternative non-penicillin antibiotics. Yet, in case of severe infections, such as syphilis, there may be no alternatives to penicillin.

Women developing anaphylaxis during labor and delivery often react to latex. If you have a history of latex allergy, your doctor will suggest that you conduct allergy testing before labor and delivery. Since the skin testing to latex may potentially lead to a severe allergic reaction, specialists recommend getting a serum IgE ELISA test. In case you are allergic. You will then be offered a latex-free environment for labor and delivery.

How to Treat Anaphylaxis During Pregnancy?


The treatment of anaphylactic reactions in pregnant and non-pregnant women is more or less the same and involves an injection of epinephrine (adrenaline) and then a follow-up medical care. Low blood pressure caused by anaphylaxis is what needs to be taken care of next. Since low blood pressure in the mother affects the blood flow to vital organs in the fetus, the treatment may require repeated doses of epinephrine, intravenous fluids and other medications that help to control blood pressure. Medical care for anaphylaxis should be provided immediately, since reducing blood flow to the fetus for a period longer than 5 minutes can lead to severe birth defects, such as anoxic brain injuries.

Since allergic disorders can’t be cured, the only way to prevent severe reactions, including anaphylaxis, is to avoid exposure to the allergens. If you have a history of reacting to certain foods, medications, latex and insect stings, it is important that your pregnancy is also supervised by an allergy specialist.

Most types of allergy testing are not recommended during pregnancy, due to potential risks. If testing is necessary, blood testing for allergies is a relatively safe option.


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