Herpes simplex virus (HSV) is a common and highly contagious infection that manifests in two primary forms: herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2). HSV-1 typically causes oral herpes (cold sores), while HSV-2 is most often linked to genital herpes. Both types can cause outbreaks in either oral or genital areas.
A significant portion of the global population carries these viruses; approximately 64% of people under 50 have HSV-1, and 13% of those aged 15-49 have HSV-2. Many infected individuals may not experience noticeable symptoms but can still transmit the virus. Managing herpes during pregnancy requires specific consideration for the health of both the pregnant individual and the unborn baby.
Herpes and Maternal Health
Herpes symptoms in pregnant individuals can vary. Outbreaks typically involve small, fluid-filled blisters on the skin or mucous membranes, such as the mouth, lips, nose, or genital area. These blisters eventually break, crust over, and then heal. Some individuals may also experience prodromal symptoms like tingling, itching, burning, muscle tenderness, or shooting pains before sores appear.
Recurrent outbreaks are common for those with a history of herpes. It is important for pregnant individuals to disclose any history of herpes to their healthcare providers at their initial prenatal visit. This allows for informed guidance and appropriate management throughout pregnancy. Recurrent episodes of genital herpes in a mother with existing antibodies generally pose a very low risk to the fetus.
Risks to the Developing Baby
Neonatal herpes, a rare but potentially devastating infection, is a significant concern due to its serious consequences for a developing baby. It occurs in an estimated 10 out of every 100,000 live births globally and can lead to severe health problems, including long-term disabilities or even death.
Most neonatal herpes cases (85-90%) result from exposure to the virus during passage through the birth canal. Less commonly, infection can occur in the womb (congenital herpes, 5% of cases), potentially causing conditions like microcephaly or chorioretinitis. Infection can also happen shortly after birth.
Neonatal herpes presents in three main forms:
Skin, Eye, and Mouth (SEM) disease: Involves fluid-filled blisters on the skin, eyes, or mouth (45% of cases). Untreated, it can progress and lead to permanent eye damage.
Central Nervous System (CNS) disease: Affects the brain and spinal cord (30% of cases), potentially causing seizures or developmental delays.
Disseminated disease: A widespread infection of multiple organs (25% of cases), including the liver, lungs, and brain.
Symptoms are often non-specific, such as irritability, lethargy, poor feeding, or breathing difficulties, typically appearing within the first three weeks of life. Skin blisters are common (70% of infected newborns) but not always present. The risk of transmission is substantially higher (up to 50%) if the pregnant individual acquires a primary herpes infection late in pregnancy, as protective antibodies have not yet developed. Recurrent outbreaks carry a much lower transmission risk (0-4%) due to maternal antibodies.
Managing Herpes During Pregnancy and Delivery
Managing herpes during pregnancy involves a multi-faceted approach aimed at minimizing the risk of transmission to the baby. Diagnostic tests, such as PCR of a genital swab and type-specific IgG serology, can help clarify whether an infection is primary or recurrent.
Antiviral medications, primarily acyclovir and valacyclovir, play a role in managing herpes during pregnancy. These medications are generally considered safe for use during all trimesters, with studies indicating no increased risk of birth defects. Healthcare providers often recommend suppressive antiviral therapy starting around 36 weeks of gestation and continuing until delivery. This therapy helps to reduce the frequency of herpes outbreaks, minimize asymptomatic viral shedding, and consequently decrease the likelihood of needing a Cesarean section due to active lesions.
The method of delivery is a crucial decision based on the presence of active herpes lesions or prodromal symptoms. If active genital lesions or symptoms like tingling or burning are present at the onset of labor, a Cesarean section is typically recommended. This surgical delivery method helps prevent the baby from coming into contact with the virus in the birth canal, which is the most common route of neonatal herpes transmission. If no active lesions or prodromal symptoms are present, a vaginal delivery is generally considered safe.
For pregnant individuals who acquire a primary herpes infection late in the third trimester, a Cesarean section might be recommended even without visible lesions due to the higher risk of viral shedding and insufficient time for maternal antibodies to develop. During labor, invasive procedures such as fetal scalp electrodes, forceps, or vacuum extractors are often avoided if possible. These instruments can create small breaks in the baby’s skin, potentially allowing the virus to enter.
Preventing herpes acquisition during pregnancy is an important strategy. For pregnant individuals who do not have herpes but whose partner does, several precautions can be taken. This includes avoiding sexual contact during active outbreaks and consistently using condoms, even when the partner has no visible sores, as viral shedding can occur asymptomatically. Additionally, abstaining from oral sex if the partner has oral herpes can prevent the acquisition of genital HSV-1, and some may consider abstaining from vaginal intercourse in the third trimester.