There is no evidence that COVID-19 can be transmitted from mother to child through breastfeeding, according to findings released today by UCLA researchers.
The study conducted by UCLA Health and published in the journal Pediatric Research found no evidence of transmission of SARS-CoV-2 through breast milk from recently infected mothers.
Milk samples from 110 breastfeeding women, who donated to Mommy’s Milk Human Milk Biorepository at UC San Diego between March and September 2020, were used in the study. Of those who donated milk, 65 mothers tested positive for COVID-19, while nine had symptoms but tested negative, and 36 were symptomatic but were not tested.
“In our study, we found no evidence that breast milk from mothers infected with COVID-19 contained infectious genetic material, and no clinical evidence was found to suggest that infants were infected, suggesting that breastfeeding is probably not a danger,” the leader said. author Dr. Paul Krogstad, pediatric infectious disease researcher at UCLA’s David Geffen School of Medicine.
Krogstad and colleagues found SARS-CoV-2 genetic material in the breast milk of seven women with confirmed infections or who reported being symptomatic. A second breast milk sample taken from these seven women between one and 97 days later contained no SARS-CoV-2 RNA.
The authors found no SARS-CoV-2 genetic material known as SgRNA, which is an indicator of virus replication, in the seven breast milk samples or when culturing other samples. There was no clinical evidence of infection in infants who were breastfed by the seven mothers with SARS-CoV-2 RNA in their milk.
The researchers noted that the study may have some limitations, noting that its small sample size may not capture all of the potential factors that predict the presence of SARS-CoV-2 RNA in breast milk.
However, this is the largest study to date to analyze breast milk and provides evidence that breastfeeding women with known or suspected SARS-CoV-2 infection does not carry any risk or does not lead to COVID-19 infection in their infants, the researchers said.
The other authors of the study are Dr. Grace M. Aldrovandi, Deisy Contreras, Hwee Ng and Nicole Tobin, all from UCLA.