COVID-19 human milk studies should continue without stopping breastfeeding, researchers say

Scientists have launched a number of human milk and lactation studies to determine if SARS-CoV-2 can be transmitted to infants through human milk. Three scientists, including one from Washington University in St. Louis, wrote a new perspective article in the American Journal of Human Biology making the case for human milk studies co-created with the people whose milk is under investigation — and where study findings are interpreted in the context of real-life choices and experiences.

“It is not easy to conduct human milk research during a pandemic,” said E.A. Quinn, associate professor of biological anthropology in Arts & Sciences and a co-author of the new article. She leads the Biomarkers and Milk Research Lab at Washington University. “Yet, despite the consistent lack of quality evidence for transmission of viral RNA from breast milk, some leaders are pushing ahead by altering public health and clinical practice guidance.”

“Breastfeeding and human milk are critical to maternal and infant health outcomes, especially during public health emergencies,” said Aunchalee Palmquist, corresponding author and a medical anthropologist and assistant professor in the Department of Maternal and Child Health and the Carolina Global Breastfeeding Institute at the Gillings School of Global Public Health at the University of North Carolina, Chapel Hill.

“Unequivocal recommendations to disrupt lactation due to COVID-19 reveal a blatant disregard of the potential harms that hang in the balance for parents and infants,” the authors wrote.

Co-author Ifeyinwa Asiodu, a nurse scientist and assistant professor in the Department of Family Health Care Nursing at the University of California, San Francisco School of Nursing, concurs.

“Current WHO (World Health Organization) and CDC (Centers for Disease Control and Prevention) recommendations are supportive of breastfeeding, chestfeeding and expressing human milk,” Asiodu said. “Given the current science, we know that the utilization of donor human milk is also safe as coronavirus is inactivated by pasteurization techniques conducted at HMBANA (Human Milk Banking of North America milk banks. Any mixed messages may further exacerbate disparities and inequities experienced by Black, Indigenous, People of Color (BlPOC) communities.”

Testing challenges

Since COVID-19 emerged, scientists around the world have scrambled to initiate new human milk studies and publish case reports, an effort the authors describe as a “liquid gold rush.”

When research focuses on milk as a separate entity, the question becomes: ‘Are women a risk to their milk?’

In published work, 50 COVID-19-positive individuals have had their milk tested, although some individuals have donated multiple samples over the course of infection.

Scientists have only found viral RNA in a small percentage of those samples, and repeat milk samples from the same individuals did not consistently yield identifiable viral RNA.

Complicating these efforts, the actual act of collecting milk samples for these kinds of studies also is difficult, given high risk of samples becoming contaminated through droplets in the air, skin or surfaces and containers.

“People seem drawn to fetishizing human milk as something discreet from lactation,” Quinn said. “In reality, while the majority of mothers in the United States do express milk for their infants, most lactating individuals feed their infants directly.”

“The way in which the research is constructed is, ‘Is there infectious potential of the milk?’” she said. “It focuses on the milk as a separate entity, not as part of the relationship between a breastfeeding mother and baby.

“So the question becomes: ‘Are women a risk to their milk?’ Nobody has really demonstrated that,” Quinn said.

Racial equity issues

The WHO has issued guidance that says that COVID-19 presents no reason to avoid or stop breastfeeding.

But certain influential global health and health-care authorities have subsequently put forth recommendations that contradict the WHO guidance. And these recommendations have the potential to impact certain people more than others.

“The science used to support hospital-based perinatal separation policies for COVID-19, including strongly advising against breastfeeding or provision of human milk with SARS-CoV-2 infection, are disproportionately harming BlPOC populations,” Palmquist said. “So, when we see that there are racial/ethnic disparities in breastfeeding outcomes as a result of COVID-19, we need to recognize that structural racism affects everything in pandemics from bench science to bedside practice.”

“During this public health crisis, we need evidence-based recommendations and consistent messaging that centers the health and well-being of women and lactating people, their infants and families,” Asiodu said. “Human milk research is important; however, it needs to be conducted with a racial equity and reproductive justice lens.”