Detection of cytomegalovirus, parvovirus B19 and herpes simplex viruses in cases of intrauterine fetal death: association with pathological findings.

There are previous indications that transplacental transmission of cytomegalovirus (CMV), parvovirus B19 (PB19) and herpes simplex virus types 1 and 2 (HSV-1/2) cause fetal infections, which may lead to fetal death. In a prospective case-control study we examined the incidence of these viruses in intrauterine fetal death and their association with fetal and placenta pathological findings. Molecular assays were performed on placenta tissue extracts of 62 fetal deaths and 35 controls for the detection of CMV, PB19 and HSV-1/2 genomes. Formalin-fixed, paraffin-embedded liver, spleen and placenta tissues of fetal death cases were evaluated histologically. Thirty-four percent of placental specimens taken from intrauterine fetal deaths were positive for any of the three viruses (16%, 13%, and 5% positive for CMV, PB19, and HSV-1/2, respectively), whereas only 6% of those taken from full term newborns were positive (P = 0.0017). No dual infection was observed. This difference was also observed when fetal deaths with a gestational age <20 weeks or a gestational age >20 weeks were compared with the controls (P = 0.025 and P = 0.0012, respectively). Intrauterine death and the control groups differed in the detection rate of CMV DNA (16% and 3%, respectively; P = 0.047), which was more pronounced in a gestational age >20 weeks (P = 0.03). Examination of the pathological findings among the PCR-positive and PCR-negative fetal deaths revealed that hydrops fetalis and chronic villitis were more common among the former group (P = 0.0003 and P = 0.0005, respectively). In conclusion, an association was detected between viral infection and fetal death, which was more pronounced in the advanced gestational age. Fetal hydrops and chronic villitis were evidently associated with viral DNA detection in cases of intrauterine death.