The patient is a 32-year-old woman at 35 weeks of gestation with a history of preeclampsia without severe features, characterized by proteinuria (1+ on dipstick). She has no history of chickenpox or varicella vaccination, and blood testing confirmed her lack of immunity, placing her at increased risk for severe complications from varicella infection. Two weeks before her scheduled cesarean section, her husband was diagnosed with active varicella, resulting in significant exposure to VZV.

Given her late-stage pregnancy and lack of VZV immunity, the patient is at increased risk for severe maternal infection and potential neonatal varicella. She remains asymptomatic, with no fever, rash, or malaise—however, her immunologic vulnerability due to pregnancy warrants prompt intervention.

The patient was prescribed post-exposure prophylaxis with VARIZIG and is being closely monitored for signs of VZV infection. Coordination with the neonatal care team has also been initiated to prepare for possible complications in the newborn.

Expert Consensus

• Development of varicella during pregnancy, can result in serious adverse outcomes such as congenital varicella syndrome, maternal VZV pneumonia, and neonatal varicella infection, all of which can lead to feto-maternal morbidity and mortality (Lamont RF et al., 2011).
• Close household contact with individuals actively infected with VZV, such as a spouse with chickenpox, represents a significant transmission risk. These exposures require urgent evaluation and prophylactic intervention to minimize maternal and neonatal morbidity (Lachiewicz AM and Srinivas M, 2019).
• The absence of prior varicella vaccination or history of chickenpox leaves pregnant individuals without immunity, further increasing susceptibility (CDC Yellow Book, 2024).
• Post-exposure prophylaxis with VARIZIG is the standard of care for pregnant women exposed to VZV who lack immunity (CDC Yellow Book, 2024). Administering VARIZIG as soon as possible, ideally within 96 hours of exposure (but can be administered up to 10 days following exposure), significantly reduces the severity of maternal infection and lowers the risk of neonatal varicella (Marin M et al., 2013).
• Neonatal varicella management includes isolation and postexposure prophylaxis with VARIZIG within 10 days of exposure, especially for neonates exposed around delivery, preterm infants with significant exposure, or those <28 weeks or <1,000 g at birth. Healthy term neonates exposed postnatally generally do not require prophylaxis. If VARIZIG is unavailable, IVIG or acyclovir may be used (Singh S et al., 2022).
• Due to both maternal and fetal risks from preeclampsia, the delivery plan should not be altered due to her exposure to varicella. Delivery should be based on the recommendations for pregnancies complicated by preeclampsia without severe features. So, in this case, her delivery, by repeat cesarean as she requested, would be at 37 weeks. Her exposure to varicella should not influence this decision.

Maternal and neonatal varicella can lead to serious complications, including vertical transmission, intrauterine growth restriction, low birth weight, and an increased risk of preterm birth. The most severe outcomes are linked to conditions such as Congenital Varicella Syndrome, maternal varicella pneumonia, and neonatal varicella (Lamont RF et al., 2011).

VZV in Pregnancy

While varicella infection is typically mild in children, it poses greater risks in adults, including pneumonia and encephalitis. In pregnant women, VZV infection is rare due to widespread immunity; however, when it occurs, it can result in significant maternal, fetal, and neonatal complications (ACOG, 2015).

Maternal and Fetal Risks

Varicella during pregnancy can lead to severe maternal complications, with 10–20% of infected pregnant women developing pneumonia, a significant risk factor for maternal mortality. Fetal risks include the potential for congenital varicella syndrome (CVS) when the infection occurs during the first or second trimester. CVS is rare, with risks ranging from 0.4% in the first trimester to 2% in the second trimester, and is associated with abnormalities such as skin scarring, limb hypoplasia, chorioretinitis, and microcephaly. Infections in the third trimester are not linked to CVS but may still affect the neonate (ACOG, 2015).

Neonatal Risks

Neonatal varicella infection is particularly severe when maternal disease develops from 5 days before delivery to 48 hours postpartum, as neonates lack protective maternal antibodies. These infections carry a high neonatal mortality rate due to the immaturity of the neonatal immune system. Although transmission from individuals with herpes zoster (shingles) is theoretically possible, it is extremely rare as it requires direct contact with lesions and viral shedding is lower in shingles compared to primary chickenpox. These risks emphasize the importance of preventive measures, including vaccination and timely post-exposure prophylaxis in susceptible pregnant women (ACOG, 2015).

TIMING OF DELIVERY IN COMPLEX CASES

Balancing Maternal and Fetal Risks in Timing the Delivery

The risk of life-threatening complications is highest when varicella infection occurs around the time of delivery, necessitating stringent protective measures and preventive treatment immediately after birth, even for newborns who appear fully asymptomatic. The timing of therapy is influenced by the extended incubation period characteristic of VZV infection, with viral dissemination and the appearance of a rash typically occurring 9 to 15 days after exposure (Blumental S and Lepage P, 2019).

GUIDELINES FOR MANAGING NEWBORNS AND INFANTS EXPOSED TO OR INFECTED WITH VARICELLA WITH MOTHER AS THE SOURCE OF EXPOSURE

The following are the guidelines for management (Blumental S and Lepage P, 2019):

A. Perinatal infection (mother develops symptoms between Day 5 before (D-5) and Day 2 after (D2+) delivery):

This is the highest-risk scenario for life-threatening disease in the newborn. Both mother and baby should be hospitalized for at least 3 days with airborne and contact precautions. The baby should receive VARIZIG or intravenous immunoglobulin (IVIG) (400 mg/kg) within 48–96 hours of birth. Intravenous acyclovir (30 mg/kg/day in 3 doses) should begin on day 7 after the mother’s rash onset and continue for 10 days. If intravenous access is not possible and the baby is asymptomatic, oral acyclovir may be considered with close monitoring. If the newborn develops symptoms despite treatment, acyclovir should be continued for at least 3 weeks, and underlying conditions such as immunodeficiency or viral resistance should be investigated.

B. Postnatal infection (mother develops symptoms from Day 3 to Day 28 after delivery):

The risk of neonatal infection remains high, but severe disease is less common. Babies should be treated with oral acyclovir (80 mg/kg/day in 4 doses) starting on day 7 after the maternal rash appears and continued for 7–10 days. Hospitalization with precautions is recommended if the clinical situation or social factors (eg parental compliance) warrant it. If the baby develops symptoms, they should be hospitalized and treated with intravenous acyclovir for at least 3 weeks.

C. Maternal symptoms between Day 20 and Day 6 before delivery:

Infections in this timeframe are generally mild for the newborn, although some may develop symptoms or lesions at birth. Both mother and baby should be hospitalized for at least 3 days with precautions. The baby should receive VARIZIG or IVIG (400 mg/kg) within 48–96 hours after birth. If vesicles are present at birth or appear later, oral acyclovir (80 mg/kg/day in 4 doses) should be administered for 7 days, with hospitalization duration determined by clinical and social factors.

NEONATAL VARICELLA: PREVENTION AND MANAGEMENT

Risks of Neonatal Varicella in Late Pregnancy Exposure

According to the ACOG, exposure to VZV in late pregnancy poses significant risks for neonatal varicella, especially when maternal infection occurs within 5 days before delivery or up to 2 days postpartum. During this period, there is insufficient time for maternal antibodies to transfer to the fetus, leaving the newborn highly susceptible to infection. Neonatal varicella can manifest as disseminated disease involving multiple organ systems and may lead to severe complications, including pneumonia, hepatitis, and encephalitis, which can be life-threatening (ACOG, 2015).

Neonatal Outcomes with Prompt Intervention

With timely administration of VARIZIG and, if needed, antiviral therapy, neonatal outcomes improve significantly. Prophylaxis reduces the severity and duration of the disease, lowering the risk of life-threatening complications. Early diagnosis and management are crucial in minimizing morbidity and ensuring the best possible health outcomes for neonates exposed to VZV in late pregnancy (CDC Yellow Book, 2024).

POST-EXPOSURE PROPHYLAXIS WITH VARIZIG

Guidelines for VARIZIG Use in Pregnancy Following VZV Exposure

CDC recommends VARIZIG (varicella-zoster immune globulin) as the first-line post-exposure prophylactic treatment for pregnant women exposed to VZV who lack immunity . According to guidelines, VARIZIG should be administered as soon as possible after exposure to reduce the risk of severe complications (CDC Yellow Book, 2024). This intervention is particularly critical in pregnancy, as maternal varicella infection can lead to serious outcomes for both the mother and the fetus, including varicella pneumonia and neonatal varicella (Lamont RF et al., 2011).

Efficacy of VARIZIG in Reducing the Severity of Maternal and Neonatal Varicella

Clinical studies have demonstrated that VARIZIG significantly reduces the severity of varicella in high-risk populations, including pregnant women (Levin MJ et al., 2019).

By providing passive immunity, VARIZIG may help reduce or mitigate disease symptoms in otherwise healthy pregnant individuals but does not necessarily prevent fetal infection or disease. ACOG states that since there is no conclusive evidence that VARIZIG can stop CVS or neonatal varicella, its primary use during pregnancy is aimed at minimizing the risk of severe complications from varicella in a susceptible adult such as pneumonia, rather than directly preventing infection of the fetus (ACOG, 2015).

Timing of Administration for Optimal Outcomes

Both CDC and The American Academy of Pediatrics guidelines recommend that for maximal effectiveness, VARIZIG should ideally be administered within 96 hours of VZV exposure. However, it remains effective when given up to 10 days post-exposure (Marin M et al., 2013).

Early administration is critical in reducing the likelihood of severe maternal infection and ensuring the best possible outcomes for the fetus. Timely intervention minimizes the potential for neonatal varicella, especially in cases where delivery is imminent.

Conclusion and Clinical Recommendations

Managing VZV exposure in pregnancy requires a balanced approach to addressing maternal and neonatal risks. Evidence supports early identification and management of preeclampsia through BP control, close monitoring, and timely delivery to prevent progression to severe complications. For VZV exposure in non-immune pregnant women, administering VARIZIG promptly is critical to reducing the severity of maternal infection and possibly minimizing the risk of neonatal varicella (ACOG, 2015).

Recommendations for Clinical Practice

• Prompt prophylaxis: To reduce the severity of infection, administer VARIZIG to pregnant women exposed to VZV as soon as possible, ideally within 96 hours (Marin M et al., 2013).
• Coordinated care: To effectively manage maternal and neonatal care, a multidisciplinary team, including obstetricians, infectious disease specialists, and neonatologists, should be involved.
• Close monitoring: monitor for signs of disease progression in both the mother and neonate, and provide immediate intervention when necessary.

By prioritizing proactive management and coordinated care, clinicians can achieve optimal outcomes for both the mother and the baby in complex pregnancies involving VZV exposure.