Background: Both intrauterine and sexual transmission of human herpesvirus (HHV)-6 and HHV-7 have been suggested, and congenital HHV-6 infection does occur. We prospectively studied HHV-6 and HHV-7 at multiple sites in pregnant women to determine the characteristics of these viruses at repeated time points.
Methods: Peripheral blood mononuclear cells (PBMCs), cervical secretions, placenta, and cord blood were tested by nested polymerase chain reaction (PCR) and reverse-transcriptase PCR for HHV-6 and HHV-7 and by quantitative PCR for HHV-6.