Some pregnant mothers may be passing the COVID-19 infection to their unborn babies, new studies revealed this week.
In one study released Thursday, Chinese scientists followed 33 pregnant women with COVID-19 pneumonia contracted in the city of Wuhan — the first epicenter of the deadly bug — and found that three babies, all boys, were infected with the contagion at birth.
That’s a rate of 9 percent, although in a particularly small sample, the researchers noted.
The findings were published in the Journal of the American Medical Association Pediatrics.
“Because strict infection control and prevention procedures were implemented during the delivery, it is likely that the sources of SARS-CoV-2 in the neonates’ upper respiratory tracts or anuses were maternal in origin,” the researchers wrote.
All three babies — who survived the illness — were delivered by Cesarean section because of their mothers’ conditions, the findings show.
One was delivered prematurely, at 31 weeks, because of fetal distress and needed to be resuscitated. He suffered from pneumonia, shortness of breath and sepsis — and ultimately recovered through ventilation, antibiotics and caffeine treatment in intensive care. He tested negative for the virus within seven days.
The two infants delivered on time experienced lethargy and fever, and one had pneumonia. Both recovered from the infection within six days.
Two other studies — also conducted in China and published Thursday in the Journal of American Medical Association — reported a different sign of possible mother-to-child transmission, also known as vertical transmission, ABC News reported.
The researchers detail case studies of three infants that did not have symptoms or test positive for the deadly bug but had specific antibodies or immune proteins for the infection called IgM.
Such transmission seemed unlikely at the early stages of the coronavirus outbreak, ABC reported.
Data was previously published on 19 infants born to mothers with COVID-19, all of whom tested negative for the virus, according to the report.
But the three new studies are shedding a different light, Sonja Rasmussen, a pediatrician and professor who is an expert on infections in pregnancy, told the health-news website Stat.
“I do think all these pieces taken together would lead you towards saying that it looks like vertical transmission is possible,” Rasmussen said. “[They] suggest to me that the virus can cross the placenta.”
But in an editorial published in JAMA — along with two of the new studies — doctors David Kimberlin and Sergio Stagno of the University of Alabama at Birmingham cautioned against jumping to conclusions.
“Although these 2 studies deserve careful evaluation, more definitive evidence is needed before the provocative findings they report can be used to counsel pregnant women that their fetuses are at risk from congenital infection with SARS-CoV-2,” the doctors wrote.
With Post Wires