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Genital Herpes During Pregnancy

Reviewed by James Brann, M.D.

A Baby Infected at Birth Can Have Complications

Learn about the consequences of having a genital herpes outbreak during pregnancy.

Herpes simplex virus (HSV) infection is very common in women of childbearing age. During pregnancy, the major problem if you have a HSV infection is transmission to the baby at birth. A newborn baby infected at time of birth can result in serious complications.

Herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) are common infections and; both can cause genital sores. The sores are usually open, multiple and appear as blisters.

The herpes simplex virus is passed from person to person by vaginal, oral, or anal sex. Many people who have herpes do not know that they are infected with the virus because they do not have any symptoms. But other people can develop symptoms within a few weeks of being infected with the herpes virus. The blisters can become painful open sores which then crust over as they heal.

In people with herpes, symptoms usually go away and come back. A return of symptoms is called an “outbreak that is recurrent”. In most people, the first outbreak is the worst and can last as long as 14 to 21 days. Outbreaks that happen later (recurrent herpes) are usually not as severe and do not last as long.

Outbreaks might occur every few weeks, or just once or twice a year. Certain things, called “triggers”, can make outbreaks more likely to occur. These include stress, sunlight, menstrual periods, or getting sick.

Pregnancy and HSV Infection

Pregnant women who acquire herpes for the first time during their pregnancy and have their first or primary outbreak of genital herpes around their due date are at an increased risk of having their newborn baby acquire the infection. Careful planning between you and your healthcare team can reduce the possible exposure for your baby to the virus.

Since herpes infection for the newborn baby is a very serious problem, all pregnant women should let their doctor know that they have a history of herpes infection. While rare the transmission from mother to your baby can happen if you have a recurrent sore at the time of delivery.

Because of this, antiviral treatment with acyclovir is often recommended for all pregnant women with one or more recurrences sores during pregnancy. A caesarean birth is usually recommended if you experience an outbreak of symptoms at the time of labor.

Pregnant women with no history of genital herpes, but whose partner has a history of cold sores (generally HSV type 1) or genital herpes (generally HSV type 2) should avoid oral, vaginal, and anal sex during the last trimester of pregnancy. Condoms are recommended during the entire pregnancy.

Management of Pregnant Women with Herpes Simplex Virus (HSV)

Treatment for pregnant women with primary or first episode genital infection should always be offered during pregnancy. This is because the treatment of herpes during pregnancy decreases the risk of the severity and duration of symptoms for mom and decreases the risk of infecting your newborn at birth.

Treatment may also be indicated for pregnant women that have recurrent infections to give relief of the symptoms associated with a herpes sore. Suppressive antiviral therapy for all recurrent infections should begin at 36 weeks of pregnancy to reduce the risk of lesions at the time of delivery.

Safety of Antiviral Drugs in Pregnancy

The main antiviral medication used to suppress herpes in pregnancy is acyclovir. Acyclovir during pregnancy is safe, including its use in the first trimester. Acyclovir can be used at any week of pregnancy.

Treatment of a Primary or First Genital Infection

Even though a newly acquired genital HSV sore will go away on its own, in pregnancy we recommend antiviral treatment with acyclovir (400 mg orally three times daily for 7 to 10 days) to reduce the duration of active lesions and viral shedding. For pain control, analgesia with acetaminophen can be considered along with xylocaine 2% topical jelly.

Treatment Options for Recurrent Herpes Infection

Treatment of recurrent herpes outbreaks in pregnancy are short lived and do not require treatment before 35 weeks of pregnancy. Thus many physicians do not treat the recurrence unless it is after 35 weeks.

Treatment to Suppress a Herpes Outbreak at the Time of Delivery

In both primary and recurrent herpes suppressive therapy is started at 36 weeks of pregnancy and continued to delivery. This will reduce the frequency of HSV outbreaks, decrease the chance of a recurrence at the onset of labor, and decrease the need for cesarean birth.

Suppressive therapy will also significantly reduce the risk of asymptomatic viral shedding at the time of birth. That is treatment with acyclovir will decrease viral shedding even if you do not have an active sore, thus decreasing your baby to exposure of the virus.

Treatment Recommendations by ACOG

American College of Obstetricians and Gynecologists (ACOG) recommends that “suppressive antiviral therapy be offered at 36 weeks of gestation through delivery for all women with a history of genital HSV to reduce the risk of recurrence at term, and thus the risk of cesarean delivery.”

There are three safe antiviral medications (acyclovir, famciclovir, valacyclovir), the oldest treatment and greatest clinical experience has been with acyclovir, dosed at 400 mg orally three times daily from 36 weeks of pregnancy until delivery.

Monitoring Mom with HSV during Pregnancy

The drug of choice to treat herpes in pregnancy, Acyclovir, is generally well-tolerated and does not require any special monitoring for you and your baby.

Weekly herpes cultures or polymerase chain reaction (PCR) testing for herpes during pregnancy are not recommended, as they do not predict shedding at the time of delivery. Maternal HSV is not an indication for antepartum fetal monitoring since the fetus and placenta are typically not infected.

Herpes Infection and Childbirth

The most serious complication of herpes in pregnancy is the transmission of the virus to the baby during delivery. The neonatal infection is due to contact with the virus shed from the area around the vagina as well as from the cervix. Cesarean birth does prevent the transmission to the baby and is recommended when an active sore in the genital area is present.

All women with a history of herpes when they present to the hospital to give birth should be asked if they have any prodromal symptoms of a sore starting and examined for herpes. If an active sore is found or if you have the typical prodromal symptoms such as, pain or burning, then a cesarean birth should be offered immediately with labor onset.

If your first herpes infection is during the last weeks of pregnancy, the best management is uncertain in the absence of active genital sores because viral shedding can be prolonged with the first outbreak. Most physicians will recommend cesarean birth for all women who develop herpes for the first time in the last part of their pregnancy, regardless if an active sore is present or not. The recommended cesarean birth is performed to avoid transmission to the newborn baby.

Cesarean birth is not recommended for women with recurrent HSV that do not have an active sore. This is because the risk to the baby is very low.

Cesarean birth is also not recommended for pregnant women that have an active sore, but not around the genital area. The sores on the back, buttock, and thigh should be covered with an occlusive dressing.

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