Prevalence of herpes simplex virus types 1 and 2 at maternal and fetal sides of the placenta in asymptomatic pregnant women.

PROBLEM: Herpes simplex virus 1 (HSV-1) commonly causes orolabial infection, but can also infect the genital mucosa. In contrast, HSV-2 is usually genital. Genital herpes can transmit the virus vertically to the fetus during pregnancy. We sought to estimate the prevalence of HSV-1/2 on the maternal and fetal sides of the placenta.

METHOD OF STUDY: Placental tissues were collected from pregnant women seen at the Rio Grande University Hospital. HSV-1 and HSV-2 were detected by nested PCR.

RESULTS: The prevalence of HSV-1 and HSV-2 was, respectively, 28% and 12.6% (maternal side) and 29.9% and 8.3% (fetal side). All HSV-positive women were asymptomatic. Sexual behavior, vaginal delivery, and presence of HSVs on one side of the placenta were risk factors associated with HSV infection.

CONCLUSION: The occurrence of HSVs in placental tissue was high, especially for HSV-1. Novel strategies need to be implemented for the management of asymptomatic women who might transmit HSV to their newborns.