Because breast milk contains antibodies, Block likens it to immunizations, which have been emphasized in the new health care law to control costs.
A study released this year by Harvard Medical School concluded that if 90 percent of mothers followed the standard medical advice of feeding infants only breast milk for their first six months, the United States could save $13 billion a year in health-care costs.
Breast-feeding could also prevent the premature deaths of 900 infants each year from respiratory illness and other infections, according to the study.
But some say tax officials are worried that any a new IRS ruling could be abused, according to a report in the New York Times.
"They get very uneasy about anything that smacks of food because they fear it will open up all sorts of exceptions," said Roy Ramthun, a former Treasury Department official who is now a consultant in health savings accounts. "It's a matter of cost and of protecting the integrity of the tax code."
Breast-feeding advocates say that when women go back to work after a pregnancy leave, they tend to stop nursing. The rate of breast-feeding increases with education, income and age; black women are less likely to breast-feed, while Hispanics have higher breast-feeding rates.
About 75 percent of all the 43 million mothers who gave birth in 2007 attempted breast-feeding, according to a survey by the Centers for Disease Control and Prevention.
But by the time the baby was 6 months old, only 43 percent were still nursing and by the first birthday only 22 percent.
Some progress has been made, say advocates. Congress has recently mandated under the new health law that employers provide the unpaid time and appropriate accommodations to pump and store breast milk in the workplace. "You can't do it in a hand towel in the toilet," said Kaysen.
Kelly Yates, a 33-year-old new mother from South Orange, N.J., is already stressing out about returning to her job as a project manager for a construction company.
She spent $350 on a breast pump for her now 3-month-old daughter.
"We were lucky enough to be given an electric pump as a gift when our son was born," she said by phone, while nursing her newborn.
"But there are accessories I have to replace and pieces I have to buy and those things aren't cheap either," she said. "Any amount of money you have to spend discourages people who are already struggling with breast-feeding. It's discouraging for new moms."
Irene Iannelli, a 41-year-old registered dietician consultant from Orange, Conn., said that even though breast milk is a food, in many instances pumping is a medical necessity.
"A baby needs to be fed to live," she said. "When a mother does not produce enough milk for nutritional support or cannot breast feed due to medical circumstances such as cancer or HIV, then the alternate source of nutrition is a baby formula. When a mother who has no medical instance where she is unable to breast feed her child chooses not to do so, that's a lifestyle choice."
By comparison, some of the expenditures that are allowable by the IRS seem frivolous: false teeth adhesives, pimple creams and even artificial turf for those with allergies.