Diagnosis of congenital CMV using PCR performed on formalin-fixed, paraffin-embedded placental tissue.

Congenital cytomegalovirus (CMV) infection may be asymptomatic until hearing loss manifests in childhood. Because diagnosis of congenital CMV requires viral detection within an infant’s first 21 days of life, CMV polymerase chain reaction (PCR) on formalin-fixed, paraffin-embedded (FFPE) placental t