During pregnancy, women are more susceptible to respiratory infections. The Covid-19 epidemic has therefore caused legitimate concern and led to the creation of several studies to assess the impact of this infection on pregnant women and their unborn children. One of them was carried out in a laboratory Insert from the Cochin Institute shows that the fetus responds to maternal infection even though it is not itself infected, with possible benefit to the mother.
When infected with respiratory viruses, pregnant women are at increased risk of complications. For this reason, various medical and scientific teams wanted to learn more about the events and risks associated with infection with SARS-CoV-2, the coronavirus responsible for Covid-19, during pregnancy. Among these teams, that of Sélim Aractingi, a clinician and researcher at the Cochin Institute in Paris, is working on fetal stem cells. Some of these cells pass through the umbilical cord, sometimes with a positive effect on the mother. In fact, in the event of damage, fetal stem cells can be recruited to various maternal tissues and remain there long-term, well after the birth of the child. For example, cells of fetal origin can improve maternal skin healing several years after birth. Others may modulate maternal immunity. In connection with Covid-19: “ Medical teams quickly came up with the idea of using umbilical cord blood to treat severe forms of the infection because of the immunomodulatory properties of the fetal cells », remember Sélim Aractingi and his colleague Bénédicte Oulès. The two scientists wanted to learn more about the effects of a SARS-CoV-2 infection on the composition of umbilical cord blood. In collaboration with Vassilis Tsatsaris, gynecologist and obstetrician at the Cochin-Port Royal maternity ward and director of the University Hospital Association Combating prematurity (FHU PREMA), researchers analyzed umbilical cord blood from women who were infected with SARS-CoV-2 during their pregnancy, regardless of whether they developed symptoms of Covid-19 or not. They compared its composition to that of umbilical cord blood obtained from uninfected women during pregnancy. All women participating in this study agreed to donate cord blood for research purposes after their delivery at Cochin Hospital.
A potential benefit to the mother that needs to be evaluated
This work shows that a coronavirus infection transmitted during pregnancy is not transmitted to the fetus, but still causes a reaction in the fetus. Indeed, molecular and cellular analysis of umbilical cord blood from infected mothers revealed an increase in the amount of fetal stem cells involved in the differentiation pathway that leads to the formation of red blood cells. Another observation: umbilical cord blood cells from women who have had symptoms of Covid-19 show activation of the program, generally triggered by an oxygen deficit (hypoxia pathway). “ It appears that the fetus detects maternal infection, possibly through maternal hypoxia [liée aux symptômes de la Covid-19] which is likely to cause fetal distress. This would alter the production of blood cells in the fetus and increase the number of red blood cell precursors. Transferring these precursors to the mother could help her fight hypoxia because red blood cells carry oxygen. However, this is just a hypothesis that we cannot test at this point. Our results nevertheless confirm the interest in cataloging fetal umbilical cord cells and studying their potential benefits to maternal health in a number of diseases, infectious or otherwise. », conclude the researchers.
Sélim Aractingi and Bénédicte Oulès are researchers atCochin Institute (Unit 1016 Inserm/CNRS/Université Paris Cité), in Paris.
source : M. Alkobtawi et al. Increased fetal hematopoiesis in response to symptomatic SARS-CoV-2 infection during pregnancy. Commun Med (Lond), December 11, 2023; doi: 10.1038/s43856-023–00406-6
Author: AR