SARS-CoV-2 infection in pregnancy and risk of stillbirth

Abstract

The COVID-19 pandemic has changed the lives of millions of people across the globe. As of November 2021, WHO has reported more than 250 million confirmed cases of SARS-CoV-2 infection with more than 5 million deaths. Despite the continuous efforts being made by the medical community to address the fundamental questions posed by the SARSCoV-2 infection in pregnant women and its impact over the mother and the offspring. The aim of this paper is to assess the evidence accumulated since the emergence of the pandemic concerning the impact of SARS-CoV-2 infection on the mother and fetus, especially addressing the risks of intrauterine death in SARS-CoV-2 positive mothers. We searched different databases up to November 2021 for variations of the sentence: "SARS-CoV-2 infection and COVID-19 and pregnancy and fetal death, stillbirth, intrauterine death". The changing physiological and immune responses during pregnancy make a pregnant woman more prone to developing severe forms of COVID-19, causing sometimes serious pregnancy complications such as fetal loss. At times mild general symptoms related to COVID-19 can cause serious fetal complications, suggesting that placental changes are responsible for fetal outcome. Infection with non-Delta variant increases the risk of fetal loss in the third trimester two times compared to healthy population, while Delta variant increases this risk four times. The exact mechanism of vertical transmission is still to be established and these aspects need further research especially assessing COVID-19 variant particularities.