Viruses in the placenta

Many different viruses can infect placental cells and are associated with congenital infection (Table 1). Viruses such as rubella, cytomegalovirus (CMV) and parvovirus are recognised as infectious agents of the placenta and foetus. Herpes simplex virus (HSV), varicella, human immunodeficiency virus (HIV), hepatitis B virus (HBV) and enterovirus occasionally infect the placenta and foetus, but are more commonly known as perinatal pathogens. Other viruses such as adenovirus and adeno-associated virus (AAV) have been found to infect the placenta, but a causative link between viral infection and poor pregnancy outcome has not yet been definitively established.