Chickenpox in pregnancy

What could chickenpox mean for my baby ?

If you have already had chickenpox, your baby will have the benefit of your immunity during the pregnancy and for the first seven days after it is born. You have nothing to worry about.

If you get chickenpox in the first three months of your pregnancy this does not seem to increase the risk of a miscarriage.

Only a very small number of pregnant women (about three in every thousand) catch chickenpox in the UK. An even smaller number of babies are affected in the womb.

The risks to an unborn baby depend on when its mother catches chickenpox.

If she catches it:

1… up to the 20th week of pregnancy – the baby may be infected. In just 1 to 2 of every 100 cases the baby gets shingles later in the pregnancy; this can cause damage to the eyes, legs, arms, brain, bladder or bowel. If a baby is infected, an ultrasound scan may show up some of the problems if it is done at 16-20 weeks or five weeks after the mother has caught the virus. The baby’s eyes should usually be tested shortly after it is born

2… between the 20th and 36th week – the baby will have no problems in the womb. The virus will stay in its body, however, and may show up as shingles in the first few years of its life. It will be no worse than for any other child.

3… after the 36th week and between one and four weeks before birth – the baby may get chickenpox in the womb.

4… and the baby is born within seven days of the mother’s rash appearing – the baby may get severe chickenpox; some babies may die as a result.

The birth may be more risky for a mother and her baby if she develops the rash of chickenpox within seven days of the birth.

If you get shingles while you are pregnant it is usually mild and there is no risk for you or your baby.

How can my baby be treated?

Two anti-viral drugs are available to treat chickenpox.

• Varicella-zoster immune globulin (VZIG) strengthens the immune system for a short time. It is made from human blood, given by donors. It does not necessarily prevent chickenpox developing but it may make the attack less serious. It is used before any symptoms appear; it does not work afterwards.
• Aciclovir may reduce fever and symptoms if it is started within 24 hours of the rash developing. There is not enough evidence to show whether it can prevent serious complications for mother or baby.

If you get chickenpox within five days of giving birth, or if you show symptoms within two days, your newborn baby will be given VZIG. This will not necessarily stop it getting chickenpox, but it should reduce symptoms and the risk of complications. Your baby will be checked for signs of chickenpox for about another two weeks.

If your baby is born with chickenpox it will usually be given aciclovir by injection; this should help to support the baby’s immune system and make the rash heal more quickly.

If your baby comes into contact with chickenpox within the first seven days after the birth it will be protected by any immunity you have. If you are not immune, or if you have given birth early, your baby will usually be given VZIG.