According to a new study, Covid-19 in women during pregnancy leads to an increased risk of respiratory distress in their newborn children. That respiratory distress may be caused by an over-active inflammatory response in the infants. Luckily, the risk of RD in newborns is much lower if women are vaccinated.
In the study just published in the journal Nature Communications, researchers from UCLA and the Cleveland Clinic investigated the health of infants born to women who had Covid-19. Briefly, 221 women who became infected with SARS-CoV-2 during their pregnancies and their infants were studied. About 17% of these infants exhibited signs and symptoms of respiratory distress within six months of birth. Among infants born to women not infected with SARS-CoV-2, the prevalence of RD is roughly 5%.
To investigate the causes of this increased RD risk, the investigators considered several factors. They looked at disease severity in the women, the vaccination status of the women, and whether the pregnancies went to term.
The biggest takeaways? Respiratory distress in infants was more common if women had severe Covid-19 disease, if the infants were born prematurely (less than 37 weeks gestation), or if the women were not vaccinated. In fact, the odds of respiratory distress were three times greater in infants born to unvaccinated women.
Of course, these various factors are interrelated. For example, the researchers note that 16% of unvaccinated mothers had severe or critical Covid-19 disease. Among vaccinated mothers, that number dropped to only 4%. So, the increased prevalence of RD in infants born to unvaccinated women may reflect the increased disease severity seen in these women.
It should be noted that the infants monitored in this study were not infected with the Covid-19 virus. Rather, the researchers describe them as SARS-CoV-2 exposed uninfected individuals. For some viruses, mother-to-fetus transmission is common. For a pregnant woman infected with cytomegalovirus, for instance, the risk of in utero transmission is quite high. For respiratory viruses, that risk generally is low. This seems to be true for SARS-CoV-2. Cases of in utero, or vertical, transmission of the Covid-19 virus have been reported, but it’s a rare event.
So if the newborns were not infected, then what’s causing the respiratory distress? To begin addressing this question, the researchers looked at protein levels in the blood of SARS-Cov-2 exposed uninfected infants and infants born to women who had not been infected with the Covid-19 virus. They report that several proteins associated with an inflammatory response were upregulated in the SEU infants. Perhaps, Covid-19 infection during pregnancy triggers a heightened inflammatory response in the fetus. This inflammatory response, in turn, leads to the observed respiratory distress.
However, the scientists note that several factors prevent them from concluding that this connection is causal. First, the number of individuals studied was small. Second, the increased inflammatory response in the infants could have been caused by factors other than Covid-19. Third, a direct mechanistic link between an increased inflammatory response and respiratory distress has not been elucidated. But the preliminary data are intriguing.
Numerous studies have demonstrated the safety and efficacy of the existing Covid-19 mRNA vaccines. The shots reduce the likelihood of severe disease, hospitalization, and death. Moreover, if women are vaccinated during pregnancy, then the risk of Covid-19-related hospitalization in the newborn children is reduced. With this report, we can add yet another benefit attributable to the vaccines. For pregnant women, Covid-19 vaccination prior to infection reduces the risk of respiratory distress in exposed, but uninfected newborns. As the authors of this study note, “Pregnant persons should be encouraged to receive mRNA Covid-19 vaccines.” Maternal vaccination can protect women and their children.
