in utero varicella zoster virus infection
An in utero varicella zoster virus infection is an infrequent type of in utero infection. The clinical features can be diverse and variable depending on the stage of gestation.
Epidemiology
Fetal infection with varicella is unusual in the current age due to most women of childbearing age being immune. The estimated frequency is generally very low at ~ 0.4% of pregnancies according to one study .
Pathology
The mechanism of congenital malformations caused by varicella-zoster virus seems to be not due to fetal varicella but to the development of herpes zoster in utero and to an encephalitis associated with herpes zoster . Maternal infection during the 1and 2 trimesters can give the congenital varicella syndrome which includes
- skin lesions in dermatomal distribution
- neurologic defects
- ocular diseases
- skeletal anomalies
Infection in the third trimester is not associated with it, but the infant may develop herpes zoster during the first one or two years. Maternal infection just before or after delivery presents a high risk for disseminated varicella in the infant.