Oct. 12 (UPI) -- New mothers infected with COVID-19 during pregnancy didn't pass the virus to their babies, even if they breastfed and shared the same hospital room, according to a study published Monday by JAMA Pediatrics.
Mothers with severe COVID-19, however, delivered their babies, on average, one week earlier than healthy mothers, and their babies were four times as likely to need phototherapy to treat jaundice, the data showed.
"Between our findings and other studies, it is now known that there is a relatively low likelihood of vertical transmission from [COVID-19]-positive mothers to their newborns," study co-author and pediatrician Melissa Stockwell told UPI.
"We also show that the risk remains low even with newborns rooming-in and direct breastfeeding practices, both of which had been concerns early in the pandemic," said Stockwell, division chief of child and adolescent health at NewYork-Presbyterian/Columbia University Irving Medical Center.
Pregnant women may be at increased risk for severe illness from COVID-19, and reports have appeared that the risk for preterm delivery is higher among women infected with the virus, according to data released in June by the U.S. Centers for Disease Control and Prevention.
"There remains a concern for the effect of this virus on pregnant women," study co-author Dr. Cynthia Gyamfi-Bannerman, a maternal-fetal medicine specialist at NewYork Presbyterian, told UPI.
However, no indication exists -- at least to date -- that their newborns are at any risk from the virus.
To explore the issue further, the Columbia University researchers tested 101 babies born to infected mothers in New York City between March 13 and April 24 -- the height of the COVID-19 outbreak in the region.
Two of the babes had low levels of the virus in their nasal and throat samples initially, but neither developed symptoms, and they later tested negative, the researchers said.
The remainder all tested negative at birth and, and the 31 infants who were retested several days later remained negative. All 101 babies "roomed in" -- or shared the same hospital rooms as their mothers -- and bathing was delayed, the researchers said.
Some studies have recommended early bathing of babies born to mothers with COVID-19 as a way to reduce risk for virus spread, but early bathing has other health risks, including hypothermia, they said.
Three of the 10 babies born to mothers with severe COVID-19, however, required phototherapy, while six of 91 born to mothers with mild to moderate disease required the treatment, the data showed.
"Treating babies as babies seems safe during the COVID-19 pandemic," study co-author Dr. Dani Dumitriu told UPI.
"This is particularly important given the continued spread of COVID-19 throughout the country and around the world," said Dumitriu, a neonatologist at New York-Presbyterian.