By Colleen Hurley, RD, Certified Kids Nutrition Specialist In case you were one of the many parents left wondering what to do about baby bottles, more information is revealed. It turns out; the greatest risk of baby bottles comes from heating the bottles prior to feeding time. A new study by the University of Missouri found that feeding infants from a heated plastic baby bottle poses serious health risks. The culprit is bisphenol A (BPA), which leaches when bottles are heated to about 80 degrees or filled with hot liquids. BPA is a synthetic estrogen that can cause early onset of puberty in girls, feminization in boys, breast and prostate cancer, and some forms of diabetes. About 90 percent of the baby bottles sold in the US contain BPA. University of Missouri researchers warn that parents who use plastic baby bottles to feed infants run the risk of their children developing developmental, medical, and reproductive problems in the future. Consumer groups, at a recent press conference, claim the study only confirms previous suspicions of health risks and hope the study helps eliminate the use of harmful chemicals in baby bottles. Researchers also state they found surprisingly large levels of BPA leaching out of the heat-tested bottles. Consumer groups and physicians alike hope the study sets new precedence for protecting our infants and children from potential harm. Doctors from the Institute for Health and Environment agree that we are exposing infants to risk at a time when the brain and body are rapidly developing and babies are most vulnerable. In addition, researchers note several animal studies have found BPA to be detrimental to development. However, not everyone shares the same concerns. A spokesperson for baby bottle makers feels the news is just a scare tactic for parents and that studies conducted on animals cannot adequately provide insight into human responses. It is important to note that animal studies are acceptable evidence for proving the safety of new medications. There are some things you can do to help protect your child. It is best to replace baby bottles frequently, especially when they begin to look cloudy. Also, be sure not to heat the bottle itself, only warm the liquid before pouring it into the bottle and make sure the liquid is not too hot (under 80 degrees). Makers of BPA-free plastic baby bottles and cups, Born Free provide baby bottles without the use of harmful chemicals. Nature Pure also makes glass baby bottles without chemicals. Although these baby bottles may be more expensive than regular plastic bottles initially, the price will equal out in the long run as BPA free bottles do not need to be replaced as often.