PRENATAL-DIAGNOSIS SF FETAL VARICELLA-ZOSTER VIRUS-INFECTION WITH POLYMERASE CHAIN-REACTION OF AMNIOTIC-FLUID IN 107 CASES

OBJECTIVE: Varicella, resulting from primary infection by varicella zo ster virus, carries a risk of severe congenital varicella. Prenatal di agnosis is rarely applied because methods remain to be validated. STUD Y DESIGN: From 1989 to 1994, 107 women contracted clinical varicella b efore 24 weeks of pregnancy. Amniocentesis was performed in all cases, with simultaneous fetal blood sampling in 82 cases, Virus was detecte d in amniotic fluid by cell culture inoculation and polymerase chain r eaction. Fetal blood was tested for anti-varicella tester virus immuno globulin M. RESULTS: Of the 107 amniotic fluid samples tested, nine of 107 (8.4%) were positive by polymerase chain reaction, but only two o f these (1.8%) were positive in cell culture; none of the blood sample s from infected fetuses were positive for specific anti-varicella test er Virus immunoglobulin M. The outcome of 99 pregnancies was fully doc umented. CONCLUSION: The risk of transplacental passage before 24 week s of pregnancy was 8.4% in our series. The risk of congenital varicell a is 3 in 107 (2.8%) and that of isolated postnatal varicella tester i nfection is 3 in 78 (3.8%). Polymerase chain reaction is more sensitiv e than cell culture for the detection of varicella tester virus in amn iotic fluid.