Study Shows Women Can't Transmit COVID-19 Through Breast Milk

A new study shows that while breast milk can contain genetic material from COVID, infected mothers won’t transmit the disease through breastfeeding

We still have a lot to learn about how COVID infection and vaccination can affect pregnant and nursing mothers and their babies. But a new study offers some good news: While breast milk can contain genetic material from COVID, scientists have found that it’s extremely unlikely that an infected mom could transmit the virus through breastfeeding. This supports earlier studies that have shown breastfeeding to be one way to pass on immunity to children (either from vaccination or infection), while also further showing that it’s likely safe for moms to continue breastfeeding immediately after getting vaccinated or after becoming infected with the virus.

Researchers from the University of California analyzed breast milk samples from 110 women and found that a small number of them — just 6-9 percent — had genetic materials from the COVID virus in their breast milk after becoming infected. However, the researchers said there was “no evidence” that the genetic material found in the breast milk was infectious, and could cause someone else to catch the virus. They said they were unable to culture the virus from the breastmilk samples, and that those genetic materials were just “transiently present.”

Based on those findings, the lead author of the study, Paul Krogstad, said, “breastfeeding is not likely to be a hazard” for infants after their mother tests positive, and infected moms should continue to breastfeed if they are able.

This was the largest study so far of its kind, and researchers said it offers “substantial” evidence that backs up a number of smaller studies with similar findings. It also helps bolster recommendations from public health agencies, who have said that mothers should continue to breastfeed during the pandemic. Other research has shown that mothers can pass COVID antibodies to their babies through breast milk, though researchers do not yet know how much protection children receive from those antibodies.