Researchers say the findings, published in the journal Pediatrics, underscore a need to make prolonged breastfeeding easier for women to manage.

For the study, the investigators calculated the current costs of 10 pediatric diseases for which there is evidence of a protective effect of breastfeeding -- including eczema, middle-ear infections, lower respiratory tract infections like pneumonia, asthma, type 1 diabetes and sudden infant death syndrome (SIDS).

They then estimated what the cost savings would be if 90 percent of new mothers in the U.S. breastfed exclusively for six months, as is generally recommended. The researchers calculated the direct costs of medical care, as well as indirect expenses, such as parents' time away from work to care for a sick child.

Based on their calculations, the U.S. could save $13 billion per year, as well as prevent 911 annual deaths -- mainly from SIDS, necrotizing enterocolitis (an intestinal disorder seen mainly in preterm infants) and respiratory infections.

Government survey data suggest that while most U.S. women start breastfeeding their newborns, only 32 percent are still exclusively breastfeeding at three months, and 12 percent are doing so at six months.

However, the current findings should not be seen as placing blame on non-breastfeeding mothers for healthcare and other costs, the researchers say.

We shouldn't be blaming women, because not only are they often not actively supported in attempting to breastfeed, but they are also undermined in a number of ways, lead researcher Dr. Melissa Bartick, of the Cambridge Health Alliance and Harvard Medical School in Boston, said in an interview.

Hindrances often begin immediately, according to Bartick. She said there is research showing that keeping mother and newborn in skin-to- skin contact for at least the first hour of life is important in imprinting the baby's breastfeeding behavior. But in most U.S. hospitals, Bartick noted, newborns spend that time away from their mothers, being bathed and having routine tests, and then returned to mom tightly swaddled.

But while experts agree that breast milk is the best nutrition for infants, estimating the actual financial costs of suboptimal breastfeeding rates is not straightforward.

Bartick and colleague Arnold Reinhold based their estimates on data from a 2007 report from the U.S. Agency for Healthcare Research and Quality (AHRQ), which reviewed evidence from more than 100 studies on breastfeeding and mothers' and infants' health.

The AHRQ report concluded that breastfeeding is associated with lower risks of certain infant health problems: For instance, on the basis of five studies, the report found that infants who were exclusively breastfed for three to six months were half as likely to develop middle-ear infections as babies who were exclusively formula-fed.

However, the studies the agency reviewed were almost all observational -- meaning the researchers looked at rates of a given health problem among infants whose mothers chose to breastfeed and those whose mothers did not. These types of studies cannot prove that breastfeeding itself prevents certain illnesses, because there may be other important differences between babies whose mothers breastfeed and those whose mothers do not -- though researchers try to account for those factors to the extent possible.

Still, Bartick said, there are strong associations between breastfeeding and lower risks of a number of infant health problems, and more than enough evidence supporting the biological mechanisms by which breastfeeding could help prevent those diseases.

She also pointed out that her team's estimate did not consider mothers' health. Some studies have linked breastfeeding to lower long- term risks of certain diseases in mothers -- including type 2 diabetes and breast cancer -- so the $13 billion estimate may be too conservative, according to Bartick.

My main message is that moms need more support for breastfeeding, she said.

Among her suggestions: better access to lactation counseling, which is often not covered by insurance; a scaling back in the aggressive marketing of infant formula, including the free samples given to new parents at the hospital, and paid break time for women to pump their breast milk or, where possible, offer flexible work schedules or on-site daycare.

Paid maternity leave could also help more mothers successfully breastfeed, according to Bartick. Right now, the U.S. requires employers with 50 or more workers to offer 12 weeks of non-paid maternity leave.

We're the only developed country in the world without paid maternity leave, Bartick said.

Healthcare