Study finds no evidence of SARS-CoV-2 transmission via breast milk
A small study found no evidence that mothers infected with SARS-CoV-2 transmitted the virus to their babies through breast milk, affirming previous studies.
“This article goes beyond prior small studies to provide evidence that infectious SARS-CoV-2 is not present in the milk of lactating women with recent infection, even when SARS-CoV-2 RNA is detected,” Paul A. Krogstad, MD, a professor in the departments of pediatrics and pharmacology at UCLA Health, and colleagues wrote in Pediatric Research.
In the new study, Krogstad and colleagues analyzed the breast milk of 110 women throughout the U.S., most of them white, aged in their mid-20s to mid-40s. Among them, 65 women had a confirmed SARS-CoV-2 infection, nine women had symptoms but tested negative for SARS-CoV-2 and the remaining women had symptoms but were not tested.
“The collection of breast milk samples was not directly observed and we relied on the maternal report of SARS-CoV-2 test results, symptoms and treatments received,” the researchers wrote. “However, all participants completed a semi-structured interview guided by trained study staff who prompted for specifics with the aid of a calendar.”
Krogstad and colleagues reported that among all the women, SARS-CoV-2 viral RNA was found in the breast milk of 6% of the women with either confirmed infection or symptomatic illness and 9% of the women with a positive SARS-CoV-2 diagnostic test. Infectious SARS-CoV-2 was not detected in any of the cultures, and none showed signs of subgenomic RNA, an indicator of SARS-CoV-2 replication, according to the researchers.
“To our knowledge, this study represents the largest number of breast milk samples analyzed to date from women with recent SARS-CoV-2 infection,” the researchers wrote. “Nonetheless, even this size may have been too small to permit the identification of factors that would predict the presence of SARS-CoV-2 RNA in breast milk.”
Kroger said in a press release that the study suggests “breastfeeding is not likely to be a hazard.”
COVID-19: Small study found no evidence of transmitting virus through breastfeeding. https://www.eurekalert.org/news-releases/940378. Published Jan. 18, 2022. Accessed Jan. 18, 2022.