Introduction
The placenta is a transient organ and although it is a physical barrier between maternal blood and fetal circulation, several low molecular weight substances are carried or passively cross it ensuring fetal growth and development. Viral infection in the placenta indicates a great risk of vertical transmission, which is dependent on specific maternal immune response and specific viral receptor expression in placenta or decidual cells and might result in pregnancy complications such as preterm birth, intrauterine growth restriction and miscarriage1,2,3.
In this scenario, Human Cytomegalovirus (CMV), a member ofHerpesviridae family, has ability to remain, to cross the placenta and infect the fetus, like only few pathogens are able to do. This virus is a major cause of congenital infections in humans and maternal infection may result in symptomatic disease or asymptomatic infection in the neonate. CMV may be present in both the maternal interface and in the villi which belong to the fetal tissue, indicating that it may persist in the placenta independent of fetal infection1, 4. The placenta is a reservoir for CMV and plays an important role in vertical transmission4. Cervical reactivation and shedding are important routes for prenatal transmission5,6.
The virus can be transmitted to the fetus during primary maternal infection, causing malformation and other severe symptoms and, to a lesser extent in latent reactivation or re-infection by different strains, problems in fetal development and sensorineural hearingloss. Cell permittivity is due to CMV interaction with heparin surface cell receptors expressed in many cell types, including fibroblastos, trophoblasts, macrophages and monocytes, epitelial cells, endothelial cells and muscle cells 1,7. Maternal immunity function influences viral infection but the route of CMV viral transmission includes various permissive cell types present in the placenta6-8.
The present cross-sectional study estimated CMV molecular prevalence in placenta biopsies and determined CMV DNA prevalence in the placenta and cord blood, also correlating variables and suggesting possible parameters that can assemble a more elaborate picture about the expected outcomes of a pregnancy under this condition.