Mothers of premature babies are increasingly turning to milk from donors to breast milk banks to feed their babies.
When babies are born early, their mothers are often unable to produce milk to feed them.
The International Milk Banking Initiative lists 33 nations with human milk banks, including 14 in the US and 216 in Brazil.
But where human milk sales exist, they are largely unregulated and self-policed.
Al Jazeera's John Hendren reports from Austin, Texas.