Hi found this:
Hives during pregnancy usually disappear after a few weeks of delivery of the baby. In very rare cases, it may persist beyond four weeks. Hives in pregnancy are more common when it is the first-time pregnancy case of woman. It has been observed that the condition of hives does not occur in subsequent pregnancies in the woman. Also pregnant women carrying twins in her womb tend to have higher chances of getting hives in the body.
(ooh maybe you have twins??)
Hives during pregnancy happens when the hormonal imbalance in the blood stream triggers the production of IgE antibodies by the auto-immune system of the body. When these IgE antibodies bind with the mast cells of the skin, they produce histamines. These histamines produce the allergic reaction in the body.
It also said that it can be caused by an allergic reaction to medications and drugs . so maybe try some different pre meds
Foods such as eggs, chocolates, soy, shellfish etc are known to trigger severe hives rash on the body. Food additives such as food colors are also found to be responsible for triggering hives reaction. Some people are also known to get hives when they consume medications and drugs! Animal dander, extreme cold or hot temperatures, emotional stress, excessive perspiration, wearing tight fitting clothes etc trigger the onset of hives.
Hi there
I always thought hives were brought on by stress so so more you worry the worse it will be