Scientists have claimed that by the end of 2020, approximately 300 000 infants could be born to mothers infected by SARS-CoV-2, the virus that causes Covid-19.
The study, published in the Journal of Developmental Origins of Health and Diseases, revealed that exposure to Covid-19 could pose a risk to the health and ageing of individuals who aren't even born yet.
"Millions more will be born into families who have experienced tremendous stress and upheaval due to the pandemic even if they haven't been infected themselves," said the study authors from University of Southern California (USC) in the US.
While the longer-term effects of Covid-19 on infants is yet to be seen, researchers can find some insight from the past, including the 1918 flu pandemic and previous coronavirus illnesses such as SARS in 2002 and MERS in 2012.
"The 1918 influenza pandemic had long-term impacts on the cohort exposed in utero, which experienced earlier adult mortality and more diabetes, ischemic heart disease and depression after age 50," said study author Caleb Finch from USC.
"It is possible that the Covid-19 pandemic will also have long-term impacts on the cohort that was in utero during the pandemic, from exposure to maternal infection and/or the stress of the pandemic environment," Finch added
Maternal viral infections can affect fetuses through multiple pathways, from direct transmission through the placenta to inflammatory responses that disturb in-utero metabolism and negatively affect growth.
While direct maternal-fetal transmission of the virus and severe birth defects appear to have been rare during previous coronavirus outbreaks, there were increases in preterm delivery and low birth weight during both the 2002 SARS and 2009 H1N1 influenza outbreaks, which are possible consequences of increased inflammation.
While studies on Covid-19 and pregnancy are still in their early stages, there have already been some concerning results that merit a closer look in ongoing studies, the authors wrote.
Increased rates of preterm birth may be linked to maternal SARS-CoV-2 infections, and other studies indicate that severe illness is correlated with a higher risk of stillbirth.
Other potential dangers, including the increased risk of blood clots presented by both pregnancy and severe Covid-19, also need further study.
"We suggest that to capture the consequences of viral exposure in utero for childhood development and adult health, Covid-19 birth cohort studies consider the immediate collection of data from the mother, fetus, neonate, and placenta," the team noted.