SARS-CoV-2 in Human Breast Milk and Neonatal Outcome: A Collaborative Study

Background: In the current COVID-19 pandemic caused by the SARS-Coronavirus-2 (SARS-CoV-2) it is important to understand if breast milk may be a vehicle of infection. The possible transmission of the virus via breastfeeding is still largely unexplored. Methods: This is a prospective collaborative observational study where samples of human milk from 12 breastfeeding mothers positive for SARS-Coronavirus 2 were collected. Search for the viral RNA in breast milk samples was performed by real-time PCR methodology. All the newborns underwent a clinical follow up for the first month of life or until the finding of two sequential negative swabs. Findings: In eleven cases the search for SARS-CoV-2 RNA in milk samples resulted negative and in one case it was positive. Eleven of the twelve newborns were exclusively breastfed in the first month of life and closely monitored. Clinical outcome was uneventful. Four newborns tested positive for SARS-CoV-2 and were all detected in the first 48 hours of life, after the onset of maternal symptoms. Also the clinical course of these 4 infants, including the one who received mother’s milk positive for SARS-CoV-2, was uneventful, and all of them became SARS-CoV-2 negative within 6 weeks of life. Interpretations: Our study supports the view that SARS-CoV-2 positive mothers do not expose their newborns to additional risk of infection by breastfeeding. This is an important message that should be given to mothers and healthcare providers in this moment of uncertainty due to the COVID-19 pandemic. Clearly, the recommended hygiene measures for direct breastfeeding, as well as for milk expression when a mother and her infant need to be separated, must be carefully followed. Funding: This Study was supported by University of Turin (grant RILO2019 to EB and DL). Declaration of Interests: The authors declare no conflict of interest. Ethics Approval Statement: The study was approved by the local Ethical Committee (protocol number 0039684), and informed consent to participate in the study was obtained from each mother.