Significance of the placental barrier in antenatal viral infections

Biochim Biophys Acta Mol Basis Dis. 2021 Dec 1;1867(12):166244. doi: 10.1016/j.bbadis.2021.166244. Epub 2021 Aug 16.


The placenta provides a significant physical and physiological barrier to prevent fetal infection during pregnancy. Nevertheless, it is at times breached by pathogens and leads to vertical transmission of infection from mother to fetus. This review will focus specifically on the Zika flavivirus, the HIV retrovirus and the emerging SARS-CoV2 coronavirus, which have affected pregnant women and their offspring in recent epidemics. In particular, we will address how viral infections affect the immune response at the maternal-fetal interface and how the placental barrier is physically breached and discuss the consequences of infection on various aspects of placental function to support fetal growth and development. Improved understanding of how the placenta responds to viral infections will lay the foundation for developing therapeutics to these and emergent viruses, to minimise the harms of infection to the offspring.

Keywords: Barrier function; Human immunodeficiency virus; Immune cells; Placenta; Pregnancy; Severe acute respiratory syndrome coronavirus 2; Syncytiotrophoblast; Viral infections; Zika virus.

Publication types

  • Review

MeSH terms

  • COVID-19 / metabolism
  • Female
  • Fetus / virology
  • HIV Infections / metabolism
  • HIV-1 / pathogenicity
  • Humans
  • Infectious Disease Transmission, Vertical / statistics & numerical data
  • Placenta / metabolism
  • Placenta / virology*
  • Pregnancy
  • Pregnancy Complications, Infectious / epidemiology
  • Pregnancy Complications, Infectious / virology*
  • SARS-CoV-2 / pathogenicity
  • Virus Diseases / physiopathology*
  • Zika Virus / pathogenicity
  • Zika Virus Infection / metabolism