Give and take: When the profit
Breast milk may well be an elixir for premature babies. But this ‘white gold’ can be hard to find
He r mi l k w a s t h e o n l y thing Jen Canvasser could give her babies. Born at 28 weeks, three months prematurely, Zachary and Micah each weighed less than a kilogram and were rushed to the neonatal intensive care unit. The boys were born so early that Canvasser’s milk hadn’t yet come in. She may have been a firsttime mother, but she knew this: her babies weren’t going to receive formula. She believed that milk — specifically, her milk — would give them the best start in life.
Doctors told her to try to pump every two hours to get her milk to come in. So, every other hour, around the clock, Canvasser assembled the pump in her hospital bed, attached it to her breast and willed the milk to emerge. Nothing happened.
“It was really stressful,” she says. “These little, itty-bitty guys really needed the nutrition and I was told they would be given formula if my milk did not come in.”
After two days, during which the boys were given only minimal nutrients through tubes into their veins, Canvasser finally produced a few milky drops. After filling a tiny syringe, husband Noah took the lift down to the neonatal ICU and dabbed his wife’s milk on his sons’ lips.
In that first tense, terrifying week, Zachary and Micah’s doctors came to Canvasser with more bad news: her milk wasn’t providing enough nutrition for the twins. The doctors wanted to add a high-calorie fortifier to it to help the boys grow and develop. Canvasser agreed.
But i nstead of getting better, the boys began to get worse. They stopped breathing while asleep. They began to have trouble digesting.
Canvasser’s worry turned to panic on the cold Friday afternoon of the second week when Micah began vomiting. Things got worse over the weekend. By Sunday morning, his belly had become swollen and he was constantly throwing up. On Sunday afternoon, Micah was rushed to the operating room to have part of his bowel removed. Just two weeks old, he had developed a life-threatening disease called necrotising enterocolitis, which had killed parts of his intestines. The infection was so severe, his kidneys began to fail.
Advances in caring for premature babies and very low-birthweight infants — defined as weighing less than 1.5kg at birth — mean that more of them survive longer. But this vulnerable group still has a high risk of necrotising enterocolitis. It affects about 1% to 3% of infants in the neonatal ICU and 7% of very low-birthweight infants, and up to a third of those infected will die. Numerous research studies have shown, however, that giving premature infants a diet exclusively of human milk significantly reduces the risk.
With Micah seriously ill, Canvasser finally asked the doctor about the fortifier in the boys’ milk.
“They called it a human milk for- tifier. I assumed it was some type of benign extra vitamins or something that they were adding. I had no idea what it was,” she says. “So I asked: ‘What is this fortifier? Can you show it to me?’” The bottle they showed her was a brand of formula.
After searching the internet in the wee hours of the morning, Canvasser found a fortifier made from human milk and persuaded Micah’s doctors to switch after two weeks on the formula, but his tiny body was already hopelessly damaged. At 11 months old, having spent 10 of those months in intensive care, Micah died from complications of necrotising enterocolitis.
Micah’s brother Zachary, also given formula during his neonatal ICU stay, is now a healthy, thriving three-year-old. Still, Canvasser can’t shake her fear that the formula had something to do with Micah’s death, although there’s no way to be sure.
Statistics suggest that Micah would have had a better chance on an allhuman milk diet rather than being fed with formula. But when a mother’s own milk isn’t providing enough nutrition for a vulnerable baby, the temptation is for medical staff to turn to formula rather than finding a source of human milk. Breast milk donation is on the rise, but will there ever be enough supply for all the babies who need it?
The maelstrom of hormones that help a woman give birth to her baby also tell her body to start producing milk. When the baby then sucks at her nipple, it stimulates the release of the hormone prolactin, which tells her body to produce more. Even so, it can take several days for milk to come in. For firsttime mothers, those whose babies were delivered by Caesarean section and mothers of preemies, the milk supply can take even longer to start.
On the other hand, mothers can find themselves producing more milk than their baby needs, especially if they use an electric breast pump. This has given some the option of sharing the milk their child doesn’t need.
Sharing breast milk is not new. Women have done it for millennia, letting friends’ or relatives’ hungry children nurse at their own breasts. At other times, women would handexpress their milk into pots or jars to give to families in need. And wet nurses, often impoverished or enslaved women, were often used to provide milk for wealthy children, even if it was at the expense of their ability to nurse their own. In the early 1900s, hospitals and charities began freezing and banking breast milk for sick babies.
The Human Milk Banking Association of North America, which helps to run and accredit milk banks in the United States, has gone from dispensing about 12 000 litres of pasteurised donor human milk a year in 2000 to 112 000 litres in 2014. John Honaman, its executive director, says that “more people understand the importance of what pasteurised donor human milk can do for a child”. “We’re a bridge from the time that a child is born to the time that their mom can breastfeed,” he says.
Breast milk can vary substantially from woman to woman. Mothers of preterm infants have milk that is higher in protein and fat. The composition of breast milk also changes as the baby gets older, becoming less nutrient-dense over time. But although donor milk isn’t identical to the baby’s own mother’s milk, it still has many of the same benefits, passing along valuable antibodies that protect the baby from disease.
Some parents are squeamish about giving their children milk from a stranger, but more and more neonatologists are framing it much more simply.
“We tell them that this milk is medicine,” says Amy Hair, a neonatologist at Texas Children’s Hospital in Houston.
The last few weeks of pregnancy are a busy time. Not only does the fetus continue to grow in size, organ systems are also rapidly maturing. Some of the last organs to finish developing are the brain, lungs, stomach and gut. Not surprisingly, this means that babies born prematurely often have difficulties with brain development, breathing and digesting food. Many preemies, especially those born before 32 weeks, have a digestive tract that is as thin and fragile as tissue paper, making them especially vulnerable to diseases such as necrotising enterocolitis.
Scientists aren’t sure what causes it. Mark Underwood, a neonatologist at the University of California in Davis and a leading expert on the disease, believes it is caused by an interaction between normal gut bacteria and the preemie’s still-developing immune system.
Human milk helps support the immature immune system, according to Hair and Underwood. Besides water, fat and lactose, the three largest components of breast milk, it contains many things that help fight disease, such as antibodies. It also contains human milk oligosaccharides, which can’t be digested by the baby but are the preferred food for many healthy bacteria living in the gut. If there are large numbers of healthy bacteria in the gut, that doesn’t leave room for diseasecausing ones. Another component of breast milk is lactoferrin, which binds iron, making it unavailable to dangerous bacteria that need it in order to survive. In short, breast milk creates an optimal gut environment, especially in premature infants.
Still, Underwood points out, breast milk isn’t perfect for preemies.
“Preemies are unfortunately limited in the volume they can take, and the amount of nutrients in human milk really didn’t evolve for preemies. And so we know pretty clearly, [small premature] babies who get unfortified human milk, their rate of growth is going to be poorer than if they get fortified milk, and that has an impact on their brain development as well,” he says.
Trials in the 1980s and 1990s that first compared breast milk with formula found that preemies grew better on formula because it had more calories an ounce than breast milk. More recently, neonatal ICUs have begun to fortify human milk to ensure that these babies have the nutrients they need to grow and develop as well as all the benefits of breast milk.
“If you don’t focus on nutrition and give them the appropriate amounts of protein, they rapidly lose protein … The way you add the human milk fortifier, you can actually give high protein,” says Hair. “We know mother’s milk has antibodies, immune factors; while donor milk is pasteurised and has a little less of those components, it still has quite a bit of those immune factors.”
Angel works on the fourth floor of an ageing brick highrise building, at the end of a dim, narrow hallway. The windows of her office look out on to a leafy courtyard where physicians and support staff bustle in white jackets and scrubs. The noise from Angel working nearly drowns out all sounds of conversation in the room. Angel is a squat silver chest about waist-high. She is the $100 000 milk pasteuriser imported from Britain to Norfolk, Virginia. At North America’s newest milk bank at the Children’s Hospital for the King’s Daughters, Angel sterilises about 60 litres of milk every week.
The manager of the hospital’s mothers’ milk bank, Ashlynn Baker, gave Angel her nickname because she kills deadly microbes that can