Pregnant women with coronavirus do not show symptoms during delivery in late March and early April, according to a new study.
Published in the New England Journal of Medicine, the study found that one in seven pregnant women who were admitted to two New York City hospitals for delivery were infected with the new coronavirus. However, most of them did not show symptoms.
Doctors from New York-Presbyterian Allen Hospital and the Columbia University Irving Medical Center reported that they tested a total of 215 women who gave birth to babies between March 22 and April 4.
All patients were tested for the new coronavirus upon admission to the hospital. Results showed that 33 tested positive for infection with COVID-19.
"Most of those potentially harmful or transmissible cases would have been missed if the women had not been tested," according to a team led by Dr. Dena Goffman, of Irving Medical Center.
In fact, "29 of the 33 patients [87.9%] who were positive … at admission had no symptoms of COVID-19 at presentation," Goffman noted. Only four of the 33 patients manifested typical COVID-19 symptoms, like fever.
Coronavirus testing for pregnant women
Most of the women also did not develop coronavirus symptoms either, at least over the short term. Only three of the 29 asymptomatic obstetric patients eventually showed any fever during the few days they were in the hospital.
The study points out it is not proven if the fevers were caused by COVID-19 or some other condition.
The New York City physicians who authored the report suggest that all women admitted to the hospital for obstetric care must undergo testing for the novel coronavirus.
Doing so could help "determine hospital isolation practices and bed assignments" for patients, and help in caring for newborns and the "use of personal protective equipment" by hospital staff, Goffman's group concluded.
"The new data provides an important opportunity to protect mothers, baby and health care teams during these challenging times," the study says.
Dr. Natalie Meirowitz is chief of obstetrics and gynecology/maternal fetal medicine at Long Island Jewish Medical Center in New Hyde Park, N.Y. She explained that the rate of coronavirus infection for pregnant women "probably varies quite a bit between communities."
She noted that "the women they report as asymptomatic women may have been 'pre-symptomatic' -- developing symptoms only after discharge from the hospital."
"From our experience, there are women we initially classified as asymptomatic, that subsequently recalled minor symptoms such as low grade fever or dysgeusia [loss of sense of taste] in days/weeks preceding the positive test results," said Meirowitz.
Coronavirus risks to fetus, newborns
Several reports suggest there is a low risk of the coronavirus being transmitted from an infected mother to her fetus. This is according to Dr. Justin Brandt, an assistant professor of obstetrics and gynecology in the division of maternal-fetal medicine at Rutgers Robert Wood Johnson Medical School in New Jersey.
Meanwhile, there is some research that says some babies of mothers with COVID-19 naturally have coronavirus-specific antibodies. This may mean they were exposed to the virus in the womb.
"We need more data to clarify and corroborate this risk, but there may be reason to worry about vertical transmission and associated conditions, including birth defects, early neonatal disease and other complications," Brandt said in a Rutgers news release.
