But, she said, it cannot give a sense of the prevalence of severe COVID-19 among pregnant women in the general population.
Of the 46 pregnant women who tested positive for SARS-CoV-2, the coronavirus that causes COVID-19, 43 were tested because they had symptoms. Nearly 15% developed breathing problems that landed them in the hospital.
“That’s 1 in 8,” Adams Waldorf said, “which to me is high.”
Pregnancy itself puts some degree of stress on the lungs, she explained. If a woman is also obese, or has an underlying health condition like asthma, that adds further stress.
Another big question is whether having COVID-19 during pregnancy can affect the baby. Of the women in this report, eight gave birth during the study period. That included two women who had a cesarean section, in part, to relieve their breathing difficulties.
That, Adams Waldorf said, shows the illness can affect the timing of delivery.
The risk of moms-to-be passing the virus to the fetus is a “still evolving” area of research, Langen added.
Last week, Canadian doctors reported on a newborn that likely became infected with the coronavirus while still in the womb. The good news is that baby was born healthy and did not develop COVID-19.
For now, Adams Waldorf said that pregnant women should take the recommended steps to protect themselves from infection: Stay home as much as possible, practice social distancing when they do go out, and wash hands frequently.
She also recommended that women opt for telemedicine visits when possible, especially if they are obese or have underlying health conditions.
As for childbirth in the midst of the pandemic, Langen said hospitals are “working hard to make labor and delivery safe.”
Some, including the University of Washington, are also screening women for SARS-CoV-2 when they arrive for delivery.
Last month, doctors at two hospitals in New York City — the epicenter of the U.S. outbreak — reported on their initial findings: Testing showed that 1 in 7 women who delivered between March 22 and April 4 had the coronavirus infection. But most — 88% — had no symptoms.