Pregnancy and shingles Chickenpox and shingles are caused by the varicella zoster virus. Chickenpox is a very contagious disease that commonly affects children, but is usually mild. Most people are immune to chickenpox because they had it as a child. Even if you've already had chickenpox, the virus remains inactive in your body and you may get shingles (herpes zoster) in later life if the virus is reactivated. This can happen if your immune system is low - so is more common in older people, people who are run down, people with AIDS and people receiving treatment for cancer.Shingles usually lasts for 2-4 weeks. It starts with a tingling sensation and pain in the area affected - this can vary from person to person but it tends to follow the nerve lines such as the face or around the waist. You may have a fever and feel unwell. After about five days a rash appears on one side of the body, often over the ribs. The rash starts as blisters and after about three days they turn yellowish, then crust over. If you come into contact with someone with shingles, you cannot catch shingles from them, but you can catch chickenpox from them if you've never had it.Shingles is not transmitted through the air (from coughs and sneezes) like chickenpox is. It can only be caught from contact with the rash. This is why the rash, which is usually on the body, should be kept covered.If you get shingles while you are pregnant there's no risk of complications to your baby. This is because you are already immune to chickenpox. If you get chickenpox while you are pregnant there is a risk to your baby (see separate topic).If you are pregnant and know you are not immune to chickenpox (because you didn't have it as a child) it is very important to avoid anyone with chickenpox or shingles. If you do come into contact with anyone with chickenpox or shingles see your GP immediately or call NHS Direct on 0845 4647.