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HERPES AND
PREGNANCY
"I
had several outbreaks during pregnancy and was terrified
I would pass the infection to my baby," Maria wrote
to the Herpes Resource Center. "But I didn't have
an outbreak at my delivery, and at my doctor's
recommendation I delivered vaginally. I gave birth to a
healthy, eight-pound baby girl.
"I
want to tell other mothers that I know it's hard not to
worry when your baby's safety is at stake. But please
think positive thoughts and trust your doctor. My
daughter, now 12 months, is healthy and beautiful. I
wish the same for your family. "
Maria's
story is echoed by many. While neonatal herpes is rare,
women who know they have genital herpes are often
concerned about the possibility of transmitting the
virus to their babies at birth.
On the one
hand, such concern is understandable, because herpes can
have devastating consequences for a newborn. But on the
other hand, the risk is extremely low, experts agree
especially for women with known, long-standing
infections.
Neonatal
herpes is not a reportable disease in most states, so
there are no hard statistics on the number of cases
nationwide. However, most researchers estimate between
1,000 and 3,000 cases a year in the United States, out
of a total of 4 million births. To put this in greater
perspective, an estimated 20-25% of pregnant women have
genital herpes, while less than 0.1% of babies contract
an infection. "Neonatal herpes is a remarkably rare
event", Says Zane Brown, MD, an expert on neonatal
herpes and a member of the Department of Obstetrics and
Gynecology at the University of Washington.
"Compared to all the other possible risks in a
pregnancy, the risk of neonatal herpes is extremely
small."
"I
think it's perceived to be more of a problem than it
is", says Scott Roberts, MD a researcher in the
Department of Maternal Fetal Medicine at the University
of Kansas. "The rate of neonatal herpes is very
low, even though the prevalence of genital herpes in our
country is quite common."
Transmission
rates are lowest for women who acquire herpes before
pregnancy -- one study "Randolph, JAMA, 1993)
placing the risk at about 0.04% for such women who have
no signs or symptoms of an outbreak at delivery. The
chances of transmission are highest when a woman
acquires genital herpes late in pregnancy.
Unfortunately,
when infants do contract neonatal herpes, the results
can be tragic. About half of infants who are treated
with antiviral medication escape permanent damage. But
others may suffer serious neurological damage, mental
retardation or death. It's fear of these terrible
consequences, rather than the level of risk, that makes
neonatal herpes a concern.
If you are
pregnant and you-have genital herpes, you will want to
talk with your obstetrician or midwife about how to
manage the infection and minimize the risk to your baby.
If you are a
man with either oral or genital herpes and your partner
is uninfected and pregnant, you can do even more to
protect the baby. Since the highest risk to an infant
comes when the mother contracts HSV-1 or 2 during
pregnancy, you can take steps to ensure that you don't
transmit herpes during this crucial time.
So learn
what you need to know, and then relax and enjoy the
excitement of the pregnancy -- and remind her that the
odds are strongly in favor of you're having a baby as
healthy and happy as Maria's.
How
Neonatal Herpes Is Spread
In about 90%
of cases, neonatal herpes is transmitted when an infant
comes into contact with HSV- 1 or 2 in the birth canal
during delivery. There is a high risk of transmission if
the mother has an active outbreak, because the
likelihood of viral shedding during an outbreak is high.
There is also a small risk of transmission from
asymptomatic shedding (when the virus reactivates
without causing any symptoms).
Fortunately,
babies of mothers with long-standing herpes infections
have a natural protection against the virus. Herpes
antibodies in the mother's blood cross the placenta to
the fetus. These antibodies help protect the baby from
acquiring infection during birth, even if there is some
virus in the birth canal. That's the major reason that
mothers with recurrent genital herpes rarely transmit
herpes to their babies during delivery. Even women who
acquire genital herpes during the first two trimesters
of pregnancy are usually able to supply sufficient
antibody to help protect the fetus.
Babies born
prematurely may be at a slightly increased risk,
however, even if the mother has a long-standing
infection. This is because the transfer of maternal
antibodies to the fetus begins at about 28 weeks of
pregnancy and continues until birth. "Babies
delivered at term should be protected by antibodies --
but premature babies haven't gotten a full load,
"explains Brown.
Mothers who
acquire genital herpes during the last trimester of
pregnancy may also lack the time to make enough
antibodies to send across the placenta. In addition,
newly infected people - whether pregnant or not - have a
higher rate of asymptomatic shedding for roughly a year
following a primary episode. This higher rate of
asymptomatic shedding, plus the lack of antibodies,
create the greater risk for babies whose mothers are
infected in the last trimester.
Mothers who
acquire genital herpes in the last few weeks of
pregnancy are at the highest risk of transmitting the
virus to their infants. If the mother's infection is a
true primary (she has no previous antibodies to either
HSV-1 or HSV-2), and she seroconverts (becomes HSV
positive) at the end of pregnancy, the risk of
transmission can be as high as 50%, according to
research by Brown and others. The risk is also high if
she has prior infection with HSV-1 but not HSV-2. While
acquisition of herpes in the last few weeks of pregnancy
is rare, it may account for almost half of all cases of
neonatal herpes. If a woman has primary herpes at any
point in the pregnancy, there is also the possibility of
the virus crossing the placenta and infecting the baby
in the uterus. About 5% of cases of neonatal herpes are
contracted this way.
Finally,
about 5%-8% of babies who contract neonatal herpes are
infected after birth, often when they are kissed - by an
adult who has an active infection of oral herpes (cold
sores).
Prevention:
Mothers with recurrent genital herpes
If you are
pregnant and know you have genital herpes, that fact
alone gives you a significant advantage in protecting
your baby. Studies show that most cases of neonatal
herpes occur in babies whose mothers don't have any idea
they are infected.
This
statistic is due, in part, simply to the large number of
people who have genital herpes and don't know it. But
it's also due to the lack of precautions taken by women
and doctors who don't realize that neonatal herpes is a
possibility.
When neither
the mother nor her provider knows she's infected,
neither are alert for lesions at delivery or likely to
notice mild or atypical symptoms of an outbreak. On the
other hand, when a woman and her provider do know
there's a risk, the provider can examine her visually
with a strong light at the onset of labor. This is
currently the best way to detect herpes lesions. The
provider can also take a viral culture at delivery to
aid in diagnosis, should the baby become sick later.
"If we
know you have herpes, we're going to be watching you
closely, asking you about lesions and looking for them,
and watching the baby closely afterward," says
Lawrence Stanberry, M.D., director of the Division of
Infectious Diseases, Children's Hospital Medical Center
in Cincinnati.
In addition,
findings presented at the 1994 International Herpes
Management Forum suggest that women who are educated
about genital herpes can often identify lesions even
more accurately than their doctors. Women can also
identify prodromal symptoms. Women can increase the
likelihood of a doctor's spotting mild or atypical
outbreaks by pointing to the site where lesions usually
occur.
While some
women may feel awkward discussing herpes in the delivery
room, the best course is to think of the baby's
well-being and be frank, doctors say. "It can be
hard with three or four people there you've never seen
before, but the important thing is to forget the stigma
that unfortunately exists and just come out with
it," says Roberts.
Lesion at
delivery
If a woman
does have a lesion or prodromal symptoms at delivery,
the safest practice is a cesarean delivery to prevent
the baby from coming into contact with active virus.
What are the chances that a woman with recurrent herpes
will have a lesion at delivery? Many women find that
their outbreaks tend to increase as the pregnancy
progresses, probably because of the immune suppression
that takes place to prevent the mother's body from
rejecting the fetus. Between 10% and 14% of women with
genital herpes have an active lesion at delivery. The
odds are higher for women who acquire herpes during
pregnancy, and lower for women who have had herpes for
more than six years.
Fetal scalp
monitor: trouble or no?
One practice
that may contribute to transmission of neonatal herpes
is the use of a fetal scalp monitor (scalp electrodes)
during childbirth. This instrument, which is used to
monitor the baby's heartbeat, actually makes tiny
punctures in the baby's scalp. Several studies have
shown that those breaks in the skin may serve as portals
of entry for herpes virus.
While the
risk from the scalp monitor may be quite small, a
cautious approach would be for a pregnant woman to ask
that it not be used unless there is a compelling medical
reason.
"If a
woman has a history of recurrent herpes, her
obstetrician should carefully weigh the risks and
benefits," says Stanberry. "In most cases the
fetal scalp monitor shouldn't be used. There are other
ways to monitor the heart rate." An alternative is
the external monitor, which tracks the baby's heartbeat
through the mother's abdomen.
No lesion
at delivery
If a woman
doesn't have herpes lesions at the time of delivery, the
standard of care recommended by the American College of
Obstetrics and Gynecology (ACOG) is vaginal delivery.
This does expose the baby to a very small risk of
infection from possible asymptomatic shedding. The case
for vaginal delivery is built on a number of strong
arguments.
First, the
percentage of babies who acquire neonatal herpes from
mothers who have no active lesions at delivery is
exceedingly small. In a study of 15,923 pregnant women
in Seattle, only one baby contracted neonatal herpes
from a mother with recurrent HSV who was shedding
asymptomatically at delivery (Brown, New England Journal
of Medicine, 1991). Other studies have found an even
lower rate of transmission.
"The
risk is not zero, but it's extremely low," says
Stanberry. By comparison, studies have found that many
more women shed virus at delivery -- approximately 1.4%
of women tested by viral culture, and some 20% of women
tested by ultra-sensitive PCR (polymerase chain
reaction) technology. The dramatic difference between
the numbers of babies infected and mothers shedding
virus have led researchers to conclude that even babies
who are exposed to viral shedding rarely become
infected, probably because of maternal antibodies passed
through the placenta.
The second
argument for vaginal delivery is that there is no
practical way to detect viral shedding quickly enough to
affect a delivery decision. Prior to 1988, ACOG
recommended that doctors culture women for HSV-2 in the
last few weeks before delivery, in an effort to identify
women who are shedding. However, several studies
demonstrated that these culture tests are useless for
predicting which women will be shedding at delivery, as
shedding tends to last only a few days at most.
While some
doctors still continue the practice of weekly cultures
to determine the need for a C-section, experts now
believe this simply causes unnecessary cesareans -
without providing any protection to babies.
For example,
a 1995 study at University of Texas Southwestern Medical
Center in Dallas showed that since the hospital adopted
ACOG's 1988 recommendation of delivering women with
genital herpes vaginally, in the absence of visible
lesions, the rate of cesarean delivery dropped by 37%,
and no babies had contracted neonatal herpes (Roberts et
al., Obstetrics &' Gynecology, 1995).
Some mothers
do request a C-section because they want to do
everything possible to avoid infecting their babies.
"Many mothers may be willing to put themselves at
risk for their babies," says Laurie Scott, M.D., of
the Department of Obstetrics and Gynecology at the
University of Texas. "But the reality is that a
C-section is a potentially dangerous situation."
Maternal
illness following a cesarean is approximately 28%,
compared with 1.6% following a vaginal delivery.
Cesareans require long recovery times, and in some
instances can even be fatal. "If we were doing
C-sections on every mother with genital herpes, we'd end
up losing almost as many women as we were saving
babies," says Zane Brown.
Furthermore,
the protection offered by C-sections is not absolute. In
various studies, between 16% and 30% of infants infected
with neonatal herpes were born by cesarean (in most of
these cases the cesarean was performed after the
membranes had ruptured).
At the same
time, babies delivered vaginally, even in the presence
of active lesions have an infection rate of only
0.25%-5%."Every center that does research has cases
where a lesion is identified after delivery,"
explains Brown. "The obstetrician will notice it
while stitching the mother after an episiotomy, for
example. In most cases, those babies don't get
infected". This again shows the protective power of
maternal antibodies.
In short,
for mothers with recurrent genital herpes, even the
practice of delivering by cesarean in the case of
visible lesions is conservative in light of the very few
actual cases of neonatal herpes.
"We're
not operating on mathematical assumptions," says
Scott. "We're operating on real-world observations
of how few babies get neonatal herpes."
Prevention:
Men with Genital Herpes
If you are a
man and know you have genital herpes, you have a key
role in protecting your unborn child from neonatal
herpes. As discussed above, the baby is at the greatest
risk when the mother acquires an infection during the
last trimester of pregnancy.
This happens
most often when neither parent realizes that there is a
risk of transmission. So, the first step is for both you
and your pregnant partner to find out for sure who is
infected and who is not.
At the
moment, HSV screening for all pregnant women nationwide
is not practical. An accurate, type-specific serology
(blood test) is not available in most commercial labs.
However, one accurate serology -- the Western blot -- is
available from the University of Washington at Seattle
(206-548-6066). To find out how you or your partner can
get a Western blot, ask your doctor to call the lab at
the number listed here. Your partner may also wish to
have a Western blot late in pregnancy, since two-thirds
of women who acquire genital herpes in pregnancy never
have symptoms -- meaning neither they nor their doctors
know there is a risk for neonatal herpes.
If your
partner finds that she is infected, she can talk with
her obstetrician or midwife about how to minimize the
risk at delivery. If you are infected and she is not,
you can take precautions to prevent transmission during
pregnancy.
Such
precautions include - abstaining from sex when you have
active outbreaks, using condoms for intercourse between
outbreaks, and possibly abstaining from intercourse
during the last trimester. Explore alternatives to
intercourse, such as touching, kissing, fantasizing, and
massage.
If you have
oral HSV-1 (approximately 50%-80% of adults do), avoid
oral sex when you have an active outbreak (cold sore).
HSV-1 can spread to your partner's genital area and give
her genital herpes. Some 20%-30% of neonatal herpes
cases are caused by HSV-1, so this is a real danger.
While these
precautions may mean changing your sexual practices for
a few months, you can have the reassurance of knowing
that you have prevented the single most dangerous risk
of neonatal herpes to your baby.
Women who
get herpes during pregnancy
Many women
who have their first outbreak of genital herpes during
pregnancy do not actually have a new infection -
instead, the outbreak is the first symptomatic
recurrence of a longstanding infection. If you
experience your first outbreak late in pregnancy, get a
Western blot serology, if at all possible. (See above,
for how to get a Western blot.) If performed promptly, a
Western blot can tell you whether the outbreak is a true
primary (a new infection in a person with no previous
antibodies to either HSV-1 or HSV-2), a non-primary
first episode (an infection of HSV-2 in a person with
previous antibodies to (HSV-1), or a recurrence. Ask
your doctor to let the lab know how many weeks pregnant
you are.
A woman who
has a primary episode in the last trimester, especially
in the last four to six weeks, may be treated to reduce
the viral load. Some experts might also recommend a
cesarean delivery under these circumstances. "If a
woman becomes infected during the third trimester, even
if she's treated, there's a higher risk for shedding at
delivery, says Stanberry. "In this situation, a
C-section may really be of help, even if she has no
symptoms or visible lesions." However, ACOG
recommends a vaginal delivery if no lesions are present.
Unfortunately,
most women who acquire herpes during the last trimester
are unaware of their infection. Thus, neither they nor
their babies receive the attention, treatment, and care
they would receive if the infection were known.
Experimental
approaches
Acyclovir is
occasionally prescribed for pregnant women who suffer
from extremely frequent outbreaks, or those who acquire
genital herpes during pregnancy. The use of acyclovir,
valacyclovir, or famciclovir during pregnancy is not
recommended by ACOG or approved for use during pregnancy
by the Food and Drug Administration. Ongoing studies may
clarify the role of antiviral medications.
After the
Baby Is Born
The
possibility of acquiring neonatal herpes after birth is
a risk for every baby. When such infections do occur,
the cause is almost always HSV-1, which spreads from an
adult who has an oral infection (cold sore). In many
cases, the adult is a family member who has no idea that
the minor irritation of the cold sore can be dangerous
to an infant with an immature immune system.
To help
protect your baby, educate family members about the
danger of cold sores. Don't kiss your baby when you have
an active sore, and also ask friends and relatives not
to do so. In addition, if you have an outbreak of
genital herpes, be sure to wash your hands before
touching the baby. No extreme precautions are necessary.
There is no risk in holding the baby, breast feeding, or
having the baby in bed with you.
If the
baby's mother has genital herpes, it is worth keeping a
close eye on the baby for several weeks after birth,
just to make sure no infection develops. Symptoms
usually start in the first 14 days of life and may
develop any time in the first month.
Some
symptoms, such as blisters on the body, are indicative
of herpes. Others, such as lethargy, poor feeding,
irritability, or fever could stem from any of a number
of minor problems. The important point is that if
anything seems wrong with your baby, take him or her to
your pediatrician immediately, instead of waiting to see
whether the situation will improve. "If the baby
doesn't behave well, if it's feverish, irritable, has
blisters - don't delay," says Stanberry.
Make sure
you tell your pediatrician specifically if either parent
has a history of genital herpes. "OBs don't always
talk to pediatricians," notes Stanberry. Don't
assume something you've told your obstetrician gets
conveyed to your pediatrician.
At the same
time unless your baby appears to have a problem, expect
the best and concentrate your energy on getting used to
the new member of the family. "The vast majority of
babies born to mothers with genital herpes are healthy,
happy babies."
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