Study suggests fetal coronavirus infection is possible

A small study strengthens evidence that a pregnant woman infected with the coronavirus might be able to spread it to her fetus.

Researchers from Italy said Thursday that they studied 31 women with COVID-19 who delivered babies in March and April. They found signs of the virus in several samples of umbilical cord blood, the placenta and, in one case, breast milk.

Women shouldn’t panic. This doesn’t mean there’s viable virus in those places and “it’s too early to make guidelines” or to change care, said the study leader, Dr. Claudio Fenizia, an immunology specialist at the University of Milan.

But it does merit more study, especially of women who are infected earlier in their pregnancies than these women, said Fenizia, who discussed the results at a medical conference being held online because of the pandemic.

Since the start of the pandemic, doctors have wondered whether in-the-womb infection could occur. HIV, Zika and some other viruses can infect a fetus this way. Several early reports from China suggested the coronavirus might, too, although doctors suspect those women may have spread the virus to their babies during or after birth.

The new study involved women at three hospitals during the height of the outbreak in northern Italy. The virus’s genetic material was found in one umbilical cord blood sample, two vaginal swabs and one breast milk sample. Researchers also found specific, anti-coronavirus antibodies in umbilical cord blood and in milk.

In one case, “there’s strong evidence suggesting that the newborn was born already positive because we found the virus in the umblilical cord blood and in the placenta,” Fenizia said.

In another case, a newborn had antibodies to the coronavirus that do not cross the placenta, so they did not come from...