[Varicella-zoster virus and pregnancy]

The incidence of varicella is low in pregnant women, and estimated around 1/1000 pregnancies. Vaccination is the cornerstone of prevention, but is contraindicated during pregnancy. Varicella is more severe in pregnant women. The risk of viral pneumonia is not increased, but VZV-associated pneumonia is usually more severe in pregnant women. Infection between 0-20 WG is associated with a 2 % risk of congenital varicella syndrome. Infection between D-5 and D+2 of delivery is associated with high risk of severe neonatal infection. Non-immune pregnant women with significant exposure to VZV require post-exposure prophylaxis with specific anti-VZV immunoglobulins that should be administered ideally within 4 days post-exposure and maximum within 10 days of exposure. Anti-VZV immunoglobulins are available in France in the context of an approved expanded access to an investigational new drug. Pregnant women with varicella should receive within 24 hours antiviral treatment based either on valaciclovir or, in case of severe infection, intravenous aciclovir. Both drugs were shown safe during pregnancy, even during the first trimester. Neonates born from mothers who developed varicella between D-5 and D+2 of delivery should also receive as soon as possible specific anti-VZV immunoglobulins.