From the Guidelines
Pregnant women exposed to chickenpox should receive varicella-zoster immune globulin (VZIG) within 96 hours of exposure, ideally as soon as possible, to reduce the risk of severe varicella infection and its complications, as recommended by the most recent guidelines 1.
Key Considerations
- The standard dose of VZIG is 125 units/10 kg body weight, up to a maximum of 625 units, given as an intramuscular injection.
- If chickenpox symptoms develop despite VZIG, oral acyclovir treatment (800 mg five times daily for 7 days) should be started.
- Pregnant women with active chickenpox should be treated with acyclovir, especially if they are in the second or third trimester or have severe disease.
- Chickenpox during pregnancy poses risks including pneumonia for the mother and potential congenital varicella syndrome for the baby if infection occurs in the first 20 weeks of pregnancy.
Patient Groups
- Women who have previously had chickenpox or received the varicella vaccine are generally immune and don't require intervention after exposure.
- Any pregnant woman exposed to chickenpox should contact her healthcare provider immediately for proper assessment and management, as the risk for neonatal death has been estimated to be 31% among infants whose mothers had onset of rash <4 days before giving birth 2.
Management
- VZIG is recommended for pregnant women without evidence of immunity who have been exposed to chickenpox, as it can prevent complications of varicella in the mother rather than protecting the fetus 3.
- Neonates born to mothers who have signs and symptoms of varicella from 5 days before to 2 days after delivery should receive VZIG, regardless of whether the mother received VZIG.
From the Research
Management of Varicella Infection in Pregnancy
- The management of varicella infection in pregnancy involves several key steps, including documentation of varicella immunity status, informing non-immune pregnant women of the risks, and administering varicella zoster immunoglobulin in cases of exposure 4.
- Pregnant women who develop varicella infection should be aware of the potential adverse maternal and fetal sequelae, and detailed ultrasound and follow-up are recommended to screen for fetal consequences of infection 4.
- Women with significant varicella infection in pregnancy should be treated with oral antiviral agents, such as acyclovir, and hospital admission should be considered in cases of progression to varicella pneumonitis 4.
Post-Exposure Prophylaxis
- Post-exposure prophylaxis with varicella zoster immunoglobulin (VZIG) can reduce the risk of serious disease when administered within 72-96 hours after exposure 5.
- Acyclovir or valacyclovir can be used as post-exposure varicella prophylaxis in risk patients for whom the time window for VZIG-use has expired 5.
- Antiviral agents, such as aciclovir, can be used to prevent VZV reactivation disease in immunosuppressed patients, but the dose, duration, and patient population for its use are not well established 6.
Treatment of Varicella-Zoster Virus Infections
- Antiviral agents, such as acyclovir, valacyclovir, and famciclovir, are FDA-approved drugs for the treatment of VZV infections 7.
- New molecules, such as valnivudine hydrochloride and valomaciclovir stearate, are being developed as potential anti-VZV candidates 7.
- A cost-consequence model comparing valaciclovir and acyclovir for the treatment of herpes zoster in immunocompetent patients over 50 years of age found that valaciclovir reduced average direct medical costs per patient by 17% and indirect costs by an average of 25% 8.