Evaluation of human polyomavirus BK as a potential cause of villitis of unknown etiology and spontaneous abortion.

Polyomavirus BK (BKV) is a widely latent pathogen in man. Although viral reactivation during pregnancy has been demonstrated, and polyomaviruses have been linked to chromosomal abnormalities, a pathogenic role for BKV in fetoplacental disease has not been explored. We performed in situ hybridization studies with BKV probes on cases of villitis of unknown etiology (102), diffuse villitis (25), and spontaneous abortion (22). We found no evidence that BKV plays a role in the pathogenesis of these common fetoplacental disorders.