PRENATAL-DIAGNOSIS OF CONGENITAL VARICELLA INFECTION

Fourteen fetuses at risk of Varicella-Zoster virus (VZV) infection und erwent prenatal diagnosis at 10-24 weeks' gestation by a combination o f chorionic villus sampling, amniocentesis, and fetal blood sampling. Polymerase chain reaction (PCR) was done on Fetal and placental tissue s, using primers which define a 221 bp region of the gene coding for t he 44 kD protein of VZV. Positive cases were further analysed by dot b lot hybridization, using radiolabelled DNA probes corresponding to the Hind III fragment VZV genome. The rate of placental/fetal infection w as 36 per cent (5/14 fetuses: 2/11 in the first and 3/3 in the second trimester). At post-mortem examination, two aborted fetuses had hydroc ephaly and VZV DNA was found in most of the examined tissues. The nine women who tested negative at prenatal investigation delivered healthy neonates whose VZV-specific IgM antibody titres were negative and non e of them developed herpes zoster infection, In view of the high frequ ency of fetal VZV infection and the reported low rate of malformations , the role of invasive prenatal diagnosis in women who acquire the inf ection in the first half of gestationis mainly that of reassurance whe n the test is negative.