Women would quit nursing if pollutants found in breastmilk.

Feb 12, 2009

Geraghty SR, JC Khoury, AL Morrow and BP Lanphear. 2008. Reporting individual test results of environmental chemicals in breastmilk: potential for premature weaning. Breastfeeding Medicine 3:207-213.

Synopsis by Jennifer Adibi

A majority of breastfeeding women said if they knew the milk was tainted with pollutants they would wean their babies early out of fear of exposing them to environmental chemicals, even though nursing enhances infant body and brain development and doctors and researchers encourage it.

This study is most likely the first to actually ask women if they would change breastfeeding based on results of pollutants found in their breast milk.

In response to the survey, 65-81 percent of pregnant women said that they would immediately wean their babies if their breastmilk contained either low or high levels of phthalates, a class of chemicals used to make plastics soft. African American women were slightly more likely to take this action than white women (74 percent vs. 65 percent). Only one quarter of women would stay the course and continue to breastfeed.

Research consistently shows that breastfed infants do better in terms of physical and brain (thinking and reasoning) development than those fed formula.

While conducting the survey, the researchers discovered how little women and physicians know about chemicals in breastmilk. The public is ill-informed about the levels of environmental contaminants and whether or not they pose risks to the child. Doctors do not have a clear message to deliver to their patients, because few scientific studies address this important topic.

This study raises ethical questions for researchers and doctors: how much information should be conveyed to women, especially if the links between chemicals and effects aren't clear and if prenatal exposures have bigger effects? Should women have their breastmilk tested if they will stop nursing and lose the known benefits to their infants?

The authors make a plea to both the culprits -- the chemical manufacturers -- and the harbingers -- the researchers -- to consider the public health and ethical implications of allowing chemicals to get into breastmilk and to examine how mothers are told information.

The survey was conducted among approximately 500 pregnant women in Cincinnati, Ohio, who were participating in a research study. Breastfeeding prevalence was high overall (81%) and highest among women who were white, had a college education, were married and had a household income greater than $80,000. Even though white women were more likely to breastfeed, black women were more likely to want to know the actual levels of phthalates in their milk.

Researchers chose to ask about one chemical -- instead of many -- and settled on phthalates because they are commonly found in household products, including toys, fragrances and plastics.

Exposure to phthalates is widespread, and almost everyone in the US has them in their bodies. Animal studies show the chemicals are harmful to the development of the reprodutive system.