An antihistamine cream would help.

Last time my husband had hives he took Benadryl. Not sure if that's okay to take during pregnancy though. You'd have to check.

Washing with soap and water to get any excess off might help, but don't leave it wet too much b/c that will make it worse. Scratching also makes worse.

Keep an eye out for any other symptoms of something more serious (for example, hard time breathing or tight throat or vomiting are symptoms that you'd want to get to a hospital). I don't expect you'd get those symptoms, but good to know all the same.

You can develop allergies during pregnancy