Genital Herpes And Pregnancy
Genital Herpes during pregnancy and birth
As an expectant parent eagerly awaiting the birth of your new baby, you are probably taking a number of steps to
ensure your baby’s health. One step many experts recommend is that you become informed about herpes simplex virus
(HSV). This common virus is usually a mild infection in adults. But in infants, HSV can cause a rare, but serious,
What is Herpes Simplex virus
HSV can cause sores near the mouth (oral herpes or “cold sores”), or sores on the genitals (genital herpes). HSV-1
is the usual cause of oral herpes, and HSV-2 is the usual cause of genital herpes. But either type of HSV can
infect either part of the body. Either type can infect a baby.
How common is Herpes Simplex
Approximately 80% of New Zealand adults have oral herpes and 30% have genital herpes. These figures are based on
New Zealand studies and studies from countries with similar population groups to New Zealand. You can get genital
herpes if you have sexual contact with a partner who is infected with herpes, or if a partner who has an active
cold sore performs oral sex on you. Most people with HSV don’t know they are infected with herpes because they have
no herpes symptoms, or symptoms too mild to notice.
How can Herpes Simplex spread to an infant
Herpes simplex is most often spread to an infant
during birth if the mother has HSV in the birth canal during delivery.
HSV can also be spread to the baby if he or she is kissed by someone with an active cold sore.
In rare instances, HSV may be spread by touch, if someone touches an active cold sore and then immediately touches
How can Herpes harm a baby
HSV can cause neonatal herpes (babies up to 28 days old, infected by herpes), a rare but life-threatening disease.
Neonatal herpes can cause eye or throat infections, damage to the central nervous system, mental retardation, or
death. Medication may help prevent or reduce lasting damage if it is given early.
How many babies get neonatal Herpes
Less than 0.1% of babies born in the United States each year get neonatal-herpes. The limited information from
Australasia suggests the incidence is even lower in Australia and New Zealand (4/100,000 live births in Australia).
By contrast, some 25-30% of pregnant women have genital herpes. This means that the great majority of women with
genital herpes give birth to healthy happy babies.
Which babies are most at risk
Babies are most at risk from neonatal herpes if the mother contracts genital HSV for the first time late in
pregnancy. This is because a newly infected mother does not have antibodies against the herpes virus, so there is
no natural protection for the baby during birth. In addition, a new herpes infection is frequently active, so there
is a real chance that the herpes virus will be present in the birth canal during delivery.
What about pregnant women who have a history of Genital Herpes
Women who acquire genital herpes before they become pregnant have a very low risk (less than 1%) of transmitting
the virus to their babies. This is because their immune system makes antibodies that are passed to the baby through
the placenta. Even if HSV is active in the birth canal during delivery, the antibodies help protect the baby from
contracting HSV . In addition, if a mother knows she has genital herpes, her doctor can take steps to protect the
Protecting the Baby: Women with Genital Herpes while pregnant
If you are pregnant and you have genital herpes, you may be concerned about the risk of spreading the herpes
infection to your baby. Be reassured that the risk is extremely small – especially if you have had herpes for some
time. The following steps can help make the risk even smaller:
Genital Herpes And Pregnancy
Talk with your obstetrician or midwife. Make sure he or she knows you have genital herpes.
At the time of labour, check yourself for any symptoms in the genital area – sores, itching, tingling or
tenderness. Your health care provider will also examine you with a strong light to detect any signs of an
The choices regarding an active herpes outbreak at the time of delivery should ideally be discussed with your
obstetrician early in the pregnancy. The choices are to proceed with a vaginal delivery (avoiding routine use of
instruments) or have a caesarian section. The risk of herpes transmission with vaginal delivery is low (less than
3%) and needs to be weighed against the risk of caesarian section to the mother. Other factors that might affect
your delivery need to be considered too before a decision can be made.
Ask your LMC not to break the bag of waters around the baby unless necessary. The bag of waters may help protect
the baby against the herpes virus in the birth canal.
Ask your LMC not to use foetal scalp monitor (scalp electrodes) during labour to monitor the baby’s heart rate
unless medically necessary. This instrument makes tiny punctures in the baby’s scalp, which may allow herpes virus
to enter. In most cases, an external monitor can be used instead.
Ask that a vacuum or forceps not be used during delivery unless medically necessary. These instruments can also
cause breaks in the baby’s scalp, allowing the herpes virus to enter.
After birth, watch the baby closely for about four weeks. Symptoms of neonatal herpes include blisters on the
skin, fever, tiredness, irritability, or lack of appetite. While these can be several mild illnesses, don’t wait to
see if your baby will get better. Take him or her to the pediatrician at once. Be sure to tell the pediatrician you
have genital herpes.
The odds are strongly in favour of you having a healthy baby.
Protecting the Baby: Women who don’t have Genital Herpes
The greatest risk of neonatal herpes is to babies whose mothers contract a genital herpes infection late in
pregnancy. While this is a rare occurrence, it does happen, and can cause a serious, even life-threatening, illness
for the baby. The best way you can protect your baby is to know the facts about HSV and how to protect yourself.
The first step may be finding out whether you already carry the herpes virus. If you have a partner who knows they
have genital herpes and you don’t know whether you have it, you need to discuss this with your doctor.
How can I get tested for genital HSV
If you have symptoms, the best test is a viral culture. To perform this test, your health care provider must take a
sample from a herpes outbreak while it is active, preferably on the first day. Test results are available in about
If you don’t have symptoms, a blood test can tell you whether you carry HSV-2, the type of herpes that usually
infects the genital tract. A blood test may also tell you whether you have HSV-1, but in many cases this simply
means you have oral herpes.
The most accurate blood test is the Western blot, not currently available in New Zealand. Other commercially
available tests, such as immunoblot assays, are available through some laboratories.
Ask your doctor about these tests as it differs regionally and some tests are not accurate. Also the doctor
needs to be aware how to interpret the test in light of the clinical presentation.
How can I make sure I don’t get genital HSV
?If you test negative for genital herpes, the following steps can help protect you from getting a herpes infection
If your partner has genital herpes, abstain from sex during any active herpes outbreak. Between outbreaks, use a
condom from start to finish every time you have sexual contact, even if your partner has no symptoms. (HSV can
spread when no symptoms are present.) Consider abstaining from sex during the last trimester.
If you don’t know whether your partner has genital HSV, you may wish to ask your partner to be tested. If your
partner has genital or oral HSV, there is a very real chance that you may acquire it unless you take steps to
Do not let your partner perform oral sex on you if your partner has an active cold sore (oral herpes). This can
give you genital herpes.
What if I contract genital HSV during late pregnancy
If you experience genital herpes symptoms, or believe you have been exposed to genital HSV, tell your
obstetrician or midwife at once. However, be aware that herpes can lie dormant for several years. What appears to
be a new herpes infection is usually an old one that is causing herpes symptoms for the first time. Talk with your
provider about the best way to protect your baby. If a pregnant women gets a new genital HSV infection during the
last six weeks of pregnancy, a caesarean delivery is recommended, even if no outbreak is present, as there is a
greater than 50% risk of neonatal HSV.
How can I protect the baby after birth.
A baby can get neonatal herpes in the first eight weeks after birth. Such infections are almost always caused by
a kiss from an adult who has a cold sore. To protect your baby, don’t kiss him or her when you have a cold sore,
and ask others not to. If you have a cold sore, wash your hands before touching the baby.
For Partners of pregnant Women
If your partner is pregnant, and she does not have genital HSV, you can help ensure that the baby remains safe from
the infection. Find out whether you have a genital HSV (see “How can I get tested?”). Remember, approximately 20%
of sexually active adults have genital HSV, and most do not have herpes symptoms. If you find that you have the
herpes virus, follow these guidelines to protect your partner during the pregnancy:
Use condoms from start to finish every time you have sexual contact, even if you have no herpes symptoms. HSV
can be spread even when no symptoms are present.
If you have genital herpes outbreaks, abstain from sex until the outbreak has completely healed.
Talk with your health care provider about taking antiviral medication to suppress herpes outbreaks and to reduce
the risk of herpes transmission between outbreaks.
Consider abstaining from intercourse during the last trimester. Explore alternatives such as touching, kissing,
fantasising, and massage.
If you have cold sores (usually caused by HSV-1), avoid performing oral sex on your partner when a cold sore is
Your partner needs to tell her doctor if you have genital herpes so that all the issues can be discussed.
The best way to protect the baby from neonatal herpes is to prevent contracting genital HSV during late
pregnancy, especially during the last six weeks.