Hepatitis B in Pregnancy
How can a mother know if she has been exposed to Hepatitis B?
It is very difficult, unless there is a specific risk factor. Known risk factors include injecting drugs (with sharing of needles) and unprotected sexual encounters with multiple partners. Blood transfusion is no longer regarded as a risk factor, because all blood and blood products are screened for viral infections, including Hepatitis.
In the UK, every expectant mother is offered the test at booking. Those identified to be carrying the infection can then have protective injections given to their babies at birth. This service has been available nationwide since the spring of 2000.
What are the symptoms of Hepatitis B?
This is where the difficulty arises. For the majority of patients, it appears like mild flu and an affected person may have no symptoms at all.
There may be a little nausea and vomiting, occasionally with abdominal pain - just under the right ribcage, where the liver is situated.
Surely a person with Hepatitis B infection will have jaundice?
Probably up to half of patients with the acute infection will have no jaundice at all. Even those who have jaundice may have mild symptoms that can easily be missed. This is compounded by the fact that the symptoms are non-specific.
So once one is infected with Hepatitis B, it is there for life?
No. Nine out of ten people infected with Hepatitis B will be clear of the infection within a few months. What they are left with is immunity against it for life.
The remaining 10 per cent, however, carry the infection for life and could pass it on to others, including a baby in the womb.
So, if a pregnant woman acquires Hepatitis B infection or is a carrier before conception, the baby is at risk?
Yes. In fact babies, do not do nearly as well from the infection (compared to adults) and the majority of those who have the infection passed on by their mothers go on to develop chronic hepatitis. This may lead to chronic liver failure or even cancer of the liver.
Can Hepatitis B infection lead to miscarriage or stillbirth?
There is no evidence that Hepatitis B leads to miscarriage, preterm labour or even stillbirth. The devastating effects are to the newborn. If miscarriage, preterm labour or stillbirth happens to a Hepatitis B carrier mother, hepatitis is unlikely to be the cause.
Very rarely, if infection is acquired during pregnancy and if symptoms are severe, uterine activity may be provoked.
So how can the baby of a mother with Hepatitis B be protected?
Soon after birth, the baby is given an injection of HBIG. This is a protein that confers passive but temporary protection against Hepatitis B. To be effective it should be given within twelve hours of birth. This is combined or followed soon after with vaccination against Hepatitis B (this may be given the same day, but not on the same body site).
The vaccination will be repeated one or two more times in the next few months. Of course, the parents would have been thoroughly counseled about all this in the time leading to delivery, once the Hepatitis B carrier status has been established.
Do these measures protect all newborns?
No, but up to 90 per cent will be protected. It is assumed that the small proportion who do not benefit from the vaccination are those who acquired the infection from the mother long before delivery and it had plenty of time to establish itself.
Since there is a small risk of vaccination at birth not being effective, can this not be given to the mother during pregnancy, to cover this prospect?
No. That will not be effective at all.
Hepatitis A in Pregnancy
We have discussed Hepatitis B; what about Hepatitis A and its risk to the unborn child?
Hepatitis A is not transmitted through body fluids but through eating contaminated food. Hepatitis A infection acquired by the mother during pregnancy poses no risks to the baby and cannot be passed on to her or him. As in all such cases, if symptoms are severe, they may lead to uterine activity and threatened preterm labour, but the infection itself poses no direct risk. Hepatitis A infection is always self-limiting and there is no chronic carrier status.