The US baby formula shortage has sparked interest at milk banks. At the Mothers' Milk Bank Northeast in Massachusetts, interest in donating and receiving milk has spiked, says executive director Deborah Youngblood. It's interesting the first sort of response that we got was from potential donors -- so people responding to the formula shortage with sort of an amazing, compassionate response of 'how can I be part of the solution?' People like Kayla Gillespie, a Kansas mother of three, who donated 18 gallons to the Mothers' Milk Bank in Denver six years ago and has now pledged at least 150 ounces. The Human Milk Banking Association of North America, which accredits nonprofit milk banks, says inquiries are up 20%. Parents are also turning to online breastmilk-swapping forums. Amanda Kastelein, a Connecticut mother of three, supplements the special formula she needs for 10-month-old Emerson with breast milk from a mom she found on a peer-to-peer Facebook page called Human Milk 4 Human Babies.