First-time infection of the mother is the most important factor for the transmission of genital herpes from mother to newborn. In fact, a pregnant woman who acquires genital herpes as a primary infection in the latter half of pregnancy, rather than prior to pregnancy, is at greatest risk of transmitting HSV to the baby.

Risk factors for neonatal HSV include the following:

• First-episode maternal infection in the third trimester
• Use of invasive instruments, such as use of fetal-scalp electrode monitoring and forceps / vacuum extractors
• Delivery before 38 weeks
• Maternal age less than 21 years

Symptoms of neonatal herpes encephalitis typically present between four and eleven days after the baby is delivered.  The following are signs and symptoms of neonatal HSV encephalitis.

• Rapid onset of fever
• Headache
• Seizures and tremors
• Lethargy and irritability
• Feeding poorly
• Unstable temperatures
• Fontanelle bulging (soft spot of the skull)
• Focal neurologic signs
• Impaired consciousness
• Body stiffness and/or crying that cannot be soothed or may worsen when the baby is picked up or handled
• SEM herpes is characterized by external lesions and no internal involvement
• DIS herpes affects internal organs, especially the liver

A neonatal diagnosis is determined by the following:

• Positive cerebral spinal fluid (CSF) viral cultures
• Positive immunoglobulin G against herpes simplex virus from neonatal blood
• Positive polymerase chain reactions (PCR) for herpes simplex virus from CSF

The virus progresses rapidly and death occurs within 10 – 14 days if left untreated. Long term brain injuries are common in babies that survive.

All babies with suspected or diagnosed HSV must be treated with intravenous (IV) acyclovir. Prompt treatment is crucial, especially in cases of disseminated infections. SEM HSV infections are treated for 14 days, whereas CNS or DIS infections require 21 days of therapy.

Although high dose IV acyclovir for a sufficient period has been proven to be effective, neonatal HSV infection is still associated with high residual lethality and morbidity because acyclovir may suppress but not eradicate the virus in infants.

Localized HSV usually heals without negative outcomes, whereas the CNS form is lethal in about 6% of cases. Approximately 69% of babies with CNS infection are left with permanent disabilities. The DIS infection is lethal in 31% of cases and approximately 17% of babies are left with permanent disabilities.

A history of HSV infection in all pregnant women and their partners should be obtained at the first prenatal visit. Women with a negative personal history of HSV, and especially those with a positive history in the male partner, should be strongly advised to have no oral and sexual intercourse at the time of recurrence in order to avoid infection (in particular, during the third trimester of gestation). Furthermore, use of condoms throughout pregnancy should be recommended to minimize the risk of viral acquisition, although the male partner has no active lesions. Condoms are not a complete barrier for the genital region. Thus, prophylactic administration of acyclovir or valacyclovir in the third trimester of pregnancy should be provided to all pregnant women with genital herpes during pregnancy.

A careful examination of the vulva, vagina and cervix should be performed on any woman who presents signs or symptoms of HSV
infection at the onset of labor. Artificial rupture of membranes should be avoided. All pregnant women who have a suspected active genital HSV infection or prodromal symptoms of HSV infection should undergo C-section, although membranes are intact. On the other hand, when genital herpes lesions are not present, C-section is not required but lesions near the genitals should be covered with an occlusive dressing before vaginal delivery. It is important to remember that fetal scalp electrodes monitoring during labor and vacuum or forceps delivery should be used only if necessary, since these practices increase the risk of HSV transmission. It is also imperative that all pregnant patients be given informed consent so they can make important decisions regarding their pregnancies.

Neonates born to women with active genital lesions, with a confirmed or suspected HSV infection should be:

• Isolated
• Managed with contact precautions to avoid direct contact with skin and mucosal lesions, excretions and body fluids
• Immediately treated with IV acyclovir without delay

In short, the measures to prevent transmission of HSV to newborns include the following:

• A C-section delivery should be performed on mothers with active lesions during delivery.
• Infants delivered vaginally by mothers with active genital herpes must be closely observed and treated with acyclovir.
• In pregnant women with genital herpes, supressive acyclovir should be initiated at 36 weeks’ gestation and maintained up to and during delivery, regardless of delivery mode.

Listed below are issues that may constitute negligence:

• Failure to diagnose HSV in the pregnant woman
• Failure to diagnose and treat HSV in the infant
• Failure to properly deliver the baby of an infected mother in order to avoid risks of infection in the baby, which includes failure to perform a C-section when indicated, as well as utilisation of delivery instruments and other invasive tools, such as a fetal-scalp electrode.
• Failure of the physician to obtain adequate informed consent, which includes advising the mother of the risks and alternatives of delivery methods, such as vaginal birth versus C-section delivery.

It is crucial that the physician take a thorough history of the pregnant woman, and this includes asking about HSV infection and risk factors.  If any of the risk factors for HSV are present, the physician should test the mother for HSV. If a mother has HSV, all measures must be taken – and standards of care followed – in order to prevent spread of the infection to the baby.  If the baby is at risk of getting the infection, the baby must be monitored closely after delivery, and if any signs of HSV are present, the baby must be treated and tested for the infection.