Oral and Genital Herpes
Herpes Simplex Virus (HSV) is an incurable, lifelong, recurrent sexually transmitted infection that causes open sores on various parts of the body depending on infection location, but usually includes the mouth (cold sores) and genitals.
HSV is relatively common among pregnant women, which is a concern because HSV can cause congenital or neonatal infection that can be life threatening for a newborn.
HSV can be transmitted to the fetus during pregnancy (very rare) or during delivery, as well as in the postpartum period when an adult with an open cold sore makes skin-on-skin contact with a newborn (i.e. kissing the newborn on or around the mouth).
Management of this infection requires close discussion with a woman’s HCP for screening and diagnosis, as well as antiviral therapy and delivery options in women who may have an outbreak at or near term. Management of outbreaks can significantly reduce the risk of neonatal transmission during delivery.
Note: Any woman, partner, family member, or friend who may have contact with a newborn and is experiencing an active oral herpes outbreak should avoid kissing the baby.
Background
Herpes Simplex Virus (HSV) is one of the most common sexually transmitted infections among women of reproductive age. HSV is an incurable, lifelong, recurrent infection that can be contracted and transmitted to the fetus during pregnancy. Neonatal infection that can lead to death or long-term disability in the infant.
HSV-1: traditionally the cause of oral herpes
HSV-2: traditionally the cause of genital herpes
However, either type of HSV can infect either part of the body as well as the baby. Historically, HSV-2 was always considered the genital infection; however, currently, up to 80% of new cases of HSV infection are being diagnosed as HSV-1, likely due to oral-labial transmission (mouth to vagina), which is now turning most HSV-1 infections into genital infections.
The spread of HSV is through person-to-person contact, mostly through sexual contact. However, infection can also occur through skin-to-skin and saliva-to-saliva contact, to include kissing (and kissing a newborn), especially with an active cold sore. However, infection can also occur without active sores. Infection is not spread through shared contact of surfaces such as bed sheets, bathrooms, utensils, or soap.
According to the U.S. Health and Human Services, 1 of every 6 people in the U.S. between the ages of 14 and 49 have genital herpes, an increase of 30% since the 1970s. As of 2012, it was estimated that 140 million people world-wide have HSV-1.
It is further estimated that approximately 22% of pregnant women are infected with HSV-2, 2% of women acquire genital herpes during pregnancy, and up to 90% of pregnant women that have HSV do not know they are infected.
Symptoms
Most initial infections are asymptomatic or atypical, therefore most people with HSV-2 infection have not been diagnosed. Further, most people with HSV do not know they are infected with herpes because they either have no symptoms or symptoms are too mild to notice.
HSV can cause sores near the mouth (“cold sores”), or sores on the genitals which range from mild to severe irritation. There is no way to know which type of infection someone has contracted simply by sight or location as the signs and symptoms overlap.
First-episode primary infection: a person with no prior HSV-1 or -2 antibody acquires either virus in the genital tract
First-episode nonprimary infection: a person with preexisting HSV-1 antibody acquires HSV-2 genital infection
Recurrent infection: a person with preexisting antibodies is infected with same HSV type
The classical, clinical presentation of the first episode of symptoms of primary infection, occurring in up to 25% of primary infections, is characterized by gray/white sores on the external genitalia, inner thigh, in the perianal region or on the buttocks, occurring 4 to 7 days after sexual exposure.
Primary infection can also include fever, fatigue, muscle pain, headache, urinary retention, and even meningitis. The average incubation period of a primary infection can range from 2 to 21 days, and symptoms can last up to 3 weeks. Approximately 75% of individuals will have no noticeable symptoms.
Women can also experience blistering and sores on the cervix leading to vulval pain, painful urination, vaginal discharge, and swollen lymph nodes (groin).
Pregnancy
Both HSV types commonly cause genital infection which can transfer to the baby during vaginal delivery.
The largest risk of neonatal infection occurs when a pregnant woman contracts HSV for the first time late in pregnancy, as she has no antibodies, and likely does not know she is infected (33% chance of infection transfer). Further, a primary infection late in pregnancy may cause sores to develop at delivery, significantly increasing risk of transfer during vaginal delivery.
The acquisition of genital herpes during pregnancy has been associated with miscarriage, intrauterine growth restriction, and preterm labor, along with congenital (during pregnancy) and neonatal herpes infections (vaginal delivery).
Congenital infection, although rare, is associated with severe consequences, to induce microcephaly (abnormally small head), hepatosplenomegaly (enlargement of liver and spleen), and stillbirth.
Women who acquire genital herpes before they become pregnant have a less than 1% chance of neonatal infection, even with an active infection, as their body has made antibodies that will pass to the fetus during pregnancy; however, infection is still possible.
The risk of transmission of HSV to the baby can be decreased through antiviral treatment or cesarean delivery (see Management).
Newborn
Neonatal acquisition of HSV infection occurs in an estimated 1 in 3,200 deliveries in the United States. The risk of neonatal infection varies from 30% to 50% for HSV infections in late pregnancy, whereas early pregnancy infection carries a risk of about 1%.
Congenital infection (during pregnancy; 1 in 300,000 births) is characterized by skin vesicles or scarring (most common), eye lesions, neurologic damage (microcephaly, seizures, encephalitis), growth restriction, fever, pneumonia, and/or psychomotor development; symptoms are usually evident a birth. Without treatment, an estimated 60% of infected neonates will die due to central nervous system involvement; others will have lifelong complications.
Neonatal infection (contracted during delivery) includes blisters, tiredness, irritability, and lack of appetite; the infection can also disseminate to the central nervous system causing severe complications. Fortunately, most neonatal HSV infections are limited to the skin, eyes, and mouth, and carries a good prognosis when treated. Symptoms usually appear with 1 to 3 weeks after birth.
Postpartum infection can occur after delivery. While the mother is the source of infection for congenital and labor transmission, anyone with an active cold sore who makes direct skin contact with a newborn can transfer the infection (usually from kissing a newborn on and around the mouth).
Infection can also spread, albeit more rarely, if someone touches a cold sore and then immediately touches the baby. Symptoms of this type of infection in the baby include lethargy, rash, fever, and loss of appetite.
Treatment of affected neonates/infants includes the antiviral drug acyclovir, and when given early, can prevent severe complications.
Diagnosis and Management
Diagnosis of genital herpes relies on viral culture from an active lesion (laboratory confirmation). If no symptoms are present, but a woman thinks she may have herpes, a blood test can be requested to look for antibodies which would indicate a woman was previously infected with HSV. Not all STDs are included in all screenings in early pregnancy, so women should make sure to ask their HCP if the HSV test is included.
According to U.S. Centers for Disease Control and Prevention (CDC) guidelines published in July 2021, "evidence does not support routine HSV-2...screening among asymptomatic pregnant women. However, type-specific serologic tests might be useful for identifying pregnant women at risk for HSV-2 infection and for guiding counseling regarding the risk for acquiring genital herpes during pregnancy. Routine serial cultures for HSV are not indicated for women in the third trimester who have a history of recurrent genital herpes."
Despite its prevalence, published reports on HSV in pregnancy is scarce and no clear management/treatment guidelines exist. However, the main goal in the prevention of transmission is to avoid neonatal contact with primary active genital lesions, which usually indicates cesarean delivery, especially if a woman cannot complete full antiviral therapy in time (requires 4 to 6 weeks).
Some researchers advise that vaginal delivery should be offered to women with recurrent genital herpes lesions at the onset of labor because the baby has some of the mother’s antibodies and risk of neonatal infection to the baby is considered very low (0 to 3%); other researchers disagree (including the American College of Obstetricians and Gynecologists) and advocate for cesarean delivery anytime active genital lesions are present.
Women with a known recurrent infection (not primary) should have a risks and benefits discussion with their HCP regarding vaginal delivery and cesarean section. Cesarean section is not necessary for women who have HSV but have no active genital lesions or impending genital outbreak.
Women who do deliver vaginally with active lesions will need to have their HCP avoid fetal scalp electrodes, fetal blood sampling, assisted delivery (vacuum/forceps), and artificial rupture of membranes to further eliminate risk of infection to the baby.
The most recommended antiviral drug used for HSV infections is acyclovir beginning no earlier than 36 weeks of pregnancy until delivery. It does not cure the infection, but significantly reduces viral shedding around when delivery is expected, reducing the risk of neonatal transmission and the need for cesarean delivery.
Acyclovir can be used prior to 36 weeks, but usually only if the infection is severe and/or preterm delivery is anticipated. Recent studies also suggest the use of valacyclovir.
Neither drug is officially approved for treatment of HSV in pregnant women, but neither drug is associated with fetal abnormalities, likely because it not used until very late in pregnancy. The only reported effect on the fetus appears to be a low white blood cell count, but this is considered temporary.
If therapy is completed at the time of delivery, cesarean section is not required since the risk of HSV transmission to the fetus is low.
Although acyclovir is safe, some women may not require it at all; the majority of recurrent episodes of genital herpes are short-lasting and resolve within 7 to 10 days without treatment. Women should have a risks and benefits discussion with their HCP regarding treatment, depending on their infection and stage of gestation, as well as potential delivery options.
Action
In rare cases, HSV can transfer to the fetus during pregnancy and is associated with severe consequences. Women should be screened for HSV during their first prenatal appointment (and ideally, before). If women believe they may be at risk for contracting HSV, or if they believe they may have been infected during pregnancy, they need to call their HCP immediately.
Women who have HSV and experience an active oral outbreak in the postpartum period should avoid kissing their newborn while the outbreak is active. However, women also need to wash their hands constantly to avoid touching a sore and then touching the baby.
Breastfeeding is only safe with an active outbreak as long as lesions are not on the breasts and lesions elsewhere on the woman's body do not make contact with the baby; lesions are possible on the breast.
CDC advises that women discard the milk from the affected breast(s) until the outbreak is over; women should ask their HCP to assess the breasts while lesions heal to determine when it may be safe to resume breastfeeding.
Women should also consider sharing and submitting an experience they may have regarding any sexual transmitted infection during pregnancy.
While this can be understandably private, STIs are common in all women, therefore STIs are commonly discovered during pregnancy. A shared experience can help other women learn additional perspectives regarding this concern, help end the stigma associated with STIs, and can give women courage to talk to their HCP to seek treatment.
Partners/Support
Sexual partners of pregnant women should consider getting tested and treated for HSV and other STIs. Further, if a partner of a pregnant woman has HSV, he/she should avoid skin-to-skin and saliva-to-saliva contact when there is an active sore present (which includes kissing).
Partners should also avoid having sex with any other partner while engaging in sexual contact with a pregnant woman, to avoid any possible risk an STI could be given to the pregnant woman (and baby).
Partners, family members, and any other individual who may have contact with an infant and are experiencing an active oral lesion should avoid kissing the baby. These individuals should also wash their hands often to avoid indirect contact between an active sore and the baby.
Resources
Genital HSV Infections (U.S. Centers for Disease Control and Prevention)
Management of Genital Herpes in Pregnancy: Practice Bulletin 222 (American College of Obstetricians and Gynecologists; May 2020)
Genital Herpes Facts & Brochures (U.S. Centers for Disease Control and Prevention)