The effect of the delta SARS-CoV-2 variant on maternal infection and pregnancy

Athina Samara; Asma Khalil; Patrick O'Brien; Eric Herlenius

doi:10.1016/j.isci.2022.104295

The effect of the delta SARS-CoV-2 variant on maternal infection and pregnancy

iScience. 2022 May 20;25(5):104295. doi: 10.1016/j.isci.2022.104295. Epub 2022 Apr 25.

Authors

Athina Samara^{1

2}, Asma Khalil^{3

4

5}, Patrick O'Brien^{6

7}, Eric Herlenius^{1

2}

Affiliations

¹ Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.
² Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden.
³ Fetal Medicine Unit, St George's Hospital, St George's University of London, London, UK.
⁴ Vascular Biology Research Centre, Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK.
⁵ Fetal Medicine Unit, Liverpool Women's Hospital, University of Liverpool, Liverpool, UK.
⁶ The Royal College of Obstetricians and Gynaecologists, London, UK.
⁷ University College London Hospitals NHS Foundation Trust, London, UK.

Abstract

A greater proportion of pregnant women with COVID-19 have mild disease compared with their non-pregnant counterparts. Paradoxically, however, they are at higher risk of developing severe disease, requiring respiratory support and admission to intensive care. The delta SARS-Cov-2 variant is associated with increased risk of hospitalization and morbidity in unvaccinated pregnant populations. However, it is not known whether the worse pregnancy outcomes associated with the delta variant are due to a direct effect of the virus on the pregnancy, or whether this effect is mediated through more severe maternal infection. Here, we synthesize studies of COVID-19 pregnancies, focusing on the different routes of SARS-CoV-2 infection of lung and placenta, and the mechanisms of syncytial formation for each SARS-CoV-2 variant. To delineate COVID-19 complications in pregnant women, future studies should explore whether the delta variant causes greater placental infection compared to other variants and contributes to increased syncytial formation.

Keywords: Pregnancy; Virology.

Publication types

Review