Herpes Simplex and Pregnancy

One of the most widely debated issues surrounding herpes simplex is that of the case when a woman has genital herpes during pregnancy. The reason for this concern is the threat of passing the infection on to the baby, a condition known as neonatal herpes. It must be stressed , however, that neonatal herpes is very rare. In the US around 20 per 100,000 live births have neonatal herpes simplex infection.

In the UK the figures are much lower and have been estimated at two per 100,000 births. The problem is that when neonatal herpes does occur it can have serious consequences for the baby, which is why there has been a significant amount of research on the subject.

Before going into the symptoms of neonatal herpes, it is important to realize that the mother’s antibody status at delivery influences the likelihood of the baby aquatinting infection. Mothers who were infected with herpes simplex before conception will have antibodies against the virus which pass to the fetus through the placenta. Therefore in the same way that autotransmission does not occur, so the baby will be protected acquiring a serious infection at the time of birth.

What is Neonatal Herpes?

Neonatal herpes occurs when a baby contracts HSV infection before the first moth of life. It is a serious condition because the infection spreads quickly due to the fact that the baby’ immune system is still developing and if the baby has not received antibodies from the mother through the placenta, resistance to the infection is low. The mildest form of neonatal herpes is when it is confined to the skin, eyes, and mouth, in which case antiviral treatment is prescribed and most babies will recover.

A small number of these babies are left with permanent damage, as a recent study showed. Four of 71 babies with neonatal HSV infection localized to the skin, eyes or mouth suffered long-term neurological damage. They all had HSV-2 and experienced three or more recurrences on their skin in the first year of life.

Neonatal herpes can include infection of the internal organs such as the liver, adrenals (glands that secrete hormones directly into the bloodstream), lungs, and the brain. In these cases the condition is life-threatening and even with drug treatment i.e. third of babies affected – this seriously will die. Those that do survive are often at risk of brain damage. On of the worst scenarios is when neonatal herpes affects the brain (herpes encephalitis). Antiviral treatment is prescribed but once again the outcome is not always successful. One study found that babies with neonatal HSV encephalitis deteriorated after completing antiviral treatment or had progressive deterioration over the first year of life.

At one point there was thought to be a link between having a recurrent episode of genital herpes while pregnant and having a spontaneous abortion, however more recent evidence has placed doubts on this. However, a couple of studies have shown that having a primary episode of genital herpes late in the pregnancy may increase the chances of premature labor.

How is it Transmitted?

There are several ways neonatal herpes , may occur, but in reports in only a minority of cases is it due to an infection from the mother passing the virus on to her baby. During a primary, incredibly rarely, if the mother’s illness becomes systemic, the virus may cross the placenta during pregnancy and infect the fetus, or the baby may contract it through contact with the infected birth canal during delivery. Finally the baby is more often infected soon after birth through skin-to-skin contact with an infected person. If the mother has had an infection, this would not occur, since she would have passed on her antibodies, so the source must be a relative, friend, career, etc.

Considering the widespread prevalence of the virus in the adult population, there is considerable potential for neonates to become infected with herpes simplex from an infected person. Yet the number of cases of neonatal herpes infections is infinitesimal, due to trans placental projection. The fact has led researchers to try to establish in what circumstances the infection is most easily spread to the baby.

When is Transmission Most Likely?

Infection of the neonate due to the virus crossing the placenta is thought to be rare, and when it does occur is appears to be a consequence solely of a primary infection in the mother. Or all the possible ways a baby may be infected, contact with the infected birth canal during delivery seems the least significant cause of neonatal herpes. The baby is most at risk if the mother has a genital herpes infection in the late stages of pregnancy.

Pregnant Women with a History of Genital Herpes

Research indicates that the risk of neonatal herpes is negligible when the infection is recurrent. A woman who contracts genital herpes before becoming pregnant and has a recurrent infection during her pregnancy, even in the late stages, has a much reduced chance of passing it on to her baby.

A recurrent infection during her pregnancy, even in the late stages, has a much reduced chance of passing it on her baby. A recurrent infection is less threatening because it is usually milder, less widespread and does not last long, which means there is much less replication of the virus. In addition, with a recurrent infection is less threatening because it is usually milder, less widespread and does not last long, which means there is much less replication of the virus.

In addition, with a recurrent infection lesions rarely affect the cervix (which the baby is forced against during birth). Mothers with recurrent HSV will have answered protective antibodies for the virus on to the baby during the later stages of pregnancy. The exception to this may be if the baby is born prematurely or if the immune system has not developed normally, such as when the baby is born with HIV, in which case he or she may be more at risk of becoming infected by any virus or infection.

One study involving 29 patients gives convincing evidence that recurrent symptoms of genital herpes during pregnancy are of no consequence, whereas primary infection most certainly can be. All these women experienced episodes of genital herpes for the first time during pregnancy are of no consequence, whereas primary infection most certainly can be. All these women experienced episodes of genital herpes for the first time during their pregnancy, although tests showed that around half of these had been exposed to the virus before.

Fifteen patients were diagnosed as having a primary symptom and 14 had a non-primary symptom (they had antibodies to the virus). Six babies of the 15 women with primary infection had complications due to neonatal herpes, yet none of the infants of the mothers who had non-primary first episodes had any problems of mothers who had non-primary first episodes had any problems. All mothers had vaginal births.

Women who have a history of genital herpes are often anxious about having recurrences during their pregnancy and especially at delivery. Research has shown, however, and very few women will be actually shedding the virus at delivery and if they do, the baby has antibody protection.

An American study established that a mere 1 per cent of women with evidence (clinical or serological) or prior HSV2 infection will shed the virus during delivery, and then with a normal vaginal birth only 1-5 per cent of babies born to these women will become infected. The authors of the study concluded that only one per 2,000 babies born vaginally to women with evidence of prior HSV2 infection will become infected, making neonatal herpes very rare indeed.

Primary Infection Threat

The greatest risk for neonatal infection is when the mother contracts the virus for the first time in the late stages of pregnancy. With a primary infection at delivery there is a 50 per cent chance that it will be transmitted to the baby when there is a vaginal birth. This risk is higher because a primary infection is likely to be more severe with more viral shedding and in most cases it will affect the cervix. Because the mother does not have antibodies against the infection herself, she will not be able to pass them on to the baby, making the risk of infection higher. For those reasons, a Caesarean birth, which avoids contact with the infected birth canal, will almost always be carried out.

Infectious But No Symptoms

We know that a person can shed the virus and therefor be potentially infectious to others without showing any symptoms, i.e. asymptomatic shedding. Most people do not have symptoms when they have a primary infection. Therefor asymptomatic shedding is more likely to occur as a result of a recurrent infection. As discussed earlier, a recurrent infection is much less likely to result in neonatal infection and, when there is asymptomatic shedding and even less of the virus is shed, the threat to the baby is thought to be almost non-existent.

Delivery with Genital Herpes

A primary infection is almost always accompanied by obvious symptoms such as lesions, vaginal discharge and illness. A doctor will recognize these symptoms in a pregnant women and, if they occur close to the estimated date of delivery, a Caesarean section will be carried out.

Among medical experts this procedure is indisputable. The difference in opinion over the management of genital herpes in pregnant women arises when there are recurrent symptoms at delivery. If sores are present at the onset of labor due to a recurrent episode, a Caesarean section may be recommended, especially if there are open sores around the vagina. However, many authorities believe in perfectly safe because the risk of passing the infection to the baby is so small. Instead doctors will take cultures from the baby soon after the birth to check for possible infection and, if required, antiviral treatment can begin immediately.

With recurrences the hypothetical risk of possible infection of the neonate needs to be weighed up in terms of the risks involved in a Caesarean birth. This form of delivery is regarded as ideal because it can pose a slight risk to the mother due to the fact that it involves an anesthetic and major abdominal surgery. Primary and secondary post partum hemorrhage, Mendlesons Syndrome (vomit inhaled into the lungs). Deep vein thrombosis, infection, slow recovery, but possible, as a result of Caesarean section, which is why many obstetricians try to avoid it.

If there is a recurrent episode close to delivery, the situation will be discussed between the mother and obstetrician and a decision on which form of birth is desired will be made. It must be said that medical opinion is split on this issue and a woman may receive different advice from different doctors – advice may also vary according to the hospital in which the baby will be delivered.

There are some situations that should probably be avoided if a vaginal birth is decided upon when lesions are present. A water birth is not advisable because it may increase the baby’s exposure to the virus (as the virus would also be present in the water). There is also the suggestion that fetal scalp electrodes should not be used because they could break the surface of the skin on the baby’s head, allowing another point of entry for the virus.

Monitoring for Signs of Infection

At one stage it was recommended that pregnant women with a history of genital herpes should be screened regularly up to the estimated date of delivery to see whether the virus is active. This was thought to be especially useful for detecting asymptomatic shedding. However, a better understanding of trans placental protection negates the need for this. Hence this procedure is no longer common practice and for several other reasons why. First of all, many infections were not detected because the results of the viral culture tests that are used take about one week.

It was therefore possible for a woman to have gone into labor before the results of her culture tests become available. There were also cases in which a negative result was reported but then viral shedding began a few days later at the time of the birth.

Another factor was the cost – weekly viral cultures were estimated to cost US $1.9 million for every case of neonatal herpes that was avoided. In addition, it was estimated there would be one maternal death from complications of a Caesarean section for every 10 neonatal cases prevented.

Controversy over this procedure results in the US Infectious Disease Society for Obstetrics and Gynecology publishing an editorial on this subject in the journal Obstetrics and Gynecology in 1988. It read: “With current culture techniques, weekly antenatal cultures are poor predictors of asymptomatic, culture-proved infection on the day of birth. Further, the observed risk of neonatal infection in 34 infants born vaginally to such women was zero.

It should be noted, however, that is rapid antigen detecting tests were available this procedure could be made more efficient. In reality the best and most commonly used method for detecting a genital herpes infection is a physical examination of the expectant mother at the onset of labor. If an infection does occur when you are close to full term, an informed discussion with your doctor about possible options for the birth should soon put your mind at rest.

Other Sources of Neonatal Herpes Infection

Naturally when there is a new addition to the family relatives and friends want to touch and kiss the baby.

However, certain precautions are necessary when an adult has cold sores or herpetic whitlows (herpes infection of the fingers). Babies who have not received trans-placental protection are particularly vulnerable to any infection during the first weeks of life when their immune system is developing. Most newborn babies will have antibodies to HSV1 which will have been passed on from the mother during the later stages of pregnancy; this should offer some protection but it is best to be cautious. Adults with herpes simplex infections should avoid touching newborn babies unless their lesions are adequately covered.

Drug Treatment for Mother and baby

The antiviral drug acyclovir has been prescribed with some success as a suppressive treatment for people who have regular, recurrent episodes of herpes simplex infection. Research is currently being carried out to establish whether this form of treatment is suitable for pregnant women to use in the late stages of pregnancy to suppress possible recurrences.

One study which has reported good results found that the use of acyclovir in late pregnancy presented recurrent symptoms in the majority of women with genital herpes and therefor reduced the need for Caesarean births. It is thought that acyclovir only crosses the placenta in small quantities; there are now some babies who have been born to women who received acyclovir during pregnancy and there does not seem to be any problem pregnancy and there does not seem to be any problem associated with it.

However at the moment acyclovir is not licensed for use in pregnant women and further research needs to be carried out to establish its safety during pregnancy.

When neonatal herpes does occur, it is essential that treatment begins as soon as possible because the baby’s developing immune system will not be strong enough to fight the infection. Treatment is not always successful but without it the infection is likely to spread to internal organs, placing the baby’s life at risk. All babies who are born vaginally to mothers with primary genital herpes should be monitored carefully for symptoms.

One possibility is to take viral cultures from the baby at 24 to 48 hours after the birth and, if positive, to treat with acyclovir. Any skin lesions on a newborn baby should be regarded as suspicious and tested by viral culture for HSV. When the risk of neonatal HSV is great, there is also the alternative of treating the baby with acyclovir from birth even before test results are available.

Some doctors recommend that for babies with neonatal HSV encephalitis and for those with localized HSV2 infection who have three or more skin recurrences, treatment should be long-term.

Dispelling Fear

There is a wide range of opinion in medical circles on the management of herpes simplex in pregnancy and as yet there is no definitive method for dealing with it.

Neonatal herpes is a serious and often tragic diseases, but it should also be remembered that the incidence is very low and for the vast majority of people with a history of HSV, it poses very little if any risk to the baby.

Unfortunately many pregnant women who have had episodes of genital herpes before their pregnancy are convinced they will automatically have to have a Caesarean section, which worries them. The Herpes Association in Britain counsel many such women, some of whom have been made to be afraid to conceive because of the supposed risks to their baby. Usually all the situation requires is some sensible advice from a qualified, sympathetic doctor or midwife.

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