Chickenpox is a very contagious disease which usually effects children and is fairly mild.
Although it is rare in adults, its symptoms are usually more severe.
90% of people in the UK have chickenpox during childhood, and once you have been affected once, you gain lifelong immunity to the disease. Women who did not grow up in the UK are more at risk of contracting the disease while they are pregnant because it is less likely that they suffered from it in childhood.
Chickenpox is caused by the varicella zoster virus. It is spread by breathing in droplets from the air expelled when someone with the virus coughs, sneezes or breathes. It can also be spread by touching chickenpox blisters.
The first symptoms of chickenpox in adults include a high temperature, a headache and aches and pains. Within a couple of days a spotty rash appears on the body, which eventually develops into small itchy blisters. You may feel quite unwell for several days, with a temperature, dry cough, sore throat and nausea.
The incubation period (time between catching the disease and showing symptoms) is 10-21 days. You are infectious from about two days before the rash appears until about five days after.
If you catch chickenpox when you are pregnant, there is usually nothing to worry about but you should visit your GP. Some women will be referred to hospital, especially if you catch it towards the end of your pregnancy, if you have trouble breathing, or if you experience any bleeding.
Risk to the Baby
If you catch chickenpox in the first 13 weeks of pregnancy there is a very small chance (about 1%) that the baby will develop congenital varicella syndrome which can cause eye problems, underdeveloped limbs and brain damage.
If you catch chickenpox in weeks 13-20 of pregnancy the chance that the baby will catch congenital varicella syndrome increases to about 2%.
If you catch chickenpox when you are 20-36 weeks pregnant, there is no increased risk of passing the infection to the baby. However, there is a possibility that the baby may get shingles after they are born or in later life.
If you catch chickenpox after 36 weeks of pregnancy your baby may also become infected while it is in the womb. You might need to have injections of varicella zoster immunoglobulin (VZIG) or antiviral drugs.
If you catch chickenpox up to 5 days before or up to 2 days after the birth of your baby, there is a 20% risk of your baby getting chickenpox. This can be quite serious but there are treatments available. Your baby will be given an injection of VZIG. This does not prevent them getting chickenpox but it may reduce the risk of serious complications. If your baby is born with chickenpox he or she may also be given an injection of aciclovir, an antiviral drug that will help them recover quickly.
If you are pregnant and you have contact with someone with chickenpox but you don't know if you are immune you should speak to your GP as soon as possible. In the meantime, avoid contact with other pregnant women. If you are not immune to the disease you may be gien injections to prevent the chickenpox developing. Remember, these injections are most effective within four days of coming into contact with the virus, but can be used up to ten days afterwards.
If you are planning a pregnancy you should visit your GP for a test to see if you are immune to chickenpox.
.If you have already had chickenpox you won't get it again, but there is a possibility you will get shingles if the virus is reactivated.
Shingles usually lasts for 2-4 weeks. The first symptom is a tingling sensation and pain in the area affected - commonly the face or around the waist. You may have a fever and feel unwell. After about five days a rash develops 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.
Shingles is not transmitted through the air from coughs and sneezes like chickenpox is. It can only be caught by touching the rash itself. For this reason, the rash should be kept covered up.
If you get shingles while you are pregnant there is no risk of causing harm to your baby because you are already immune to chickenpox.
If you are pregnant and you know you have never had chickenpox so you are not immune, you should avoid contact with anyone with either chickenpox or shingles.