 This is the VOA Special English Health Report. We recently told you about a study which found that more than 10% of all babies worldwide are born too early. A common problem in preterm babies is respiratory disease. The lungs are the last organs to develop. But a medicine called surfactant can save babies struggling to breathe. The story of this life-saving medicine begins with a discovery in 1959 by a researcher named Mary Ellen Avery. She told this story in 2005 to children's news at Children's Hospital Boston where she was the first woman to serve as physician-in-chief. She had been doing research at the Harvard School of Public Health. She was asked to find out more about the foam that forms in the lungs of people with a condition called pulmonary edema. At night she worked in a hospital delivery room. She saw many premature babies with a disease now called respiratory distress syndrome. She examined the lungs of babies who had died. She found there was no air in their lungs and she discovered why. In her words, the material that was important, the foam, was missing. And they were struggling to reinflate their lungs. Nature put this foam, or surfactant, in the lungs to lower surface tension. You cannot keep air spaces inflated without it. Babies usually develop this coating while they are in the womb, but many premature babies do not. Finally, in 1980, a Japanese doctor, Tetsuro Fujiwara, published a study about an artificial surfactant. It could be given to a baby and within minutes the baby could breathe. The medical community had taken years to accept Dr. Avery's discovery. But she told Harvard Medical School in 1982 that she never gave up. In her words, knowing what you want to do is important, especially in research. Dr. Anne Hansen at Children's Hospital Boston remembers the first time she heard about Dr. Avery. It was in 1990 when the government was in the process of approving a surfactant called exosurf. The doctor she was working with had some exciting news for her. She said it was the last night before the hospital would start giving exosurf to all its preterm babies. And then he told her the story of Mary Ellen Avery. Dr. Avery was 84 years old when she died late last year. For VOA Special English, I'm Mario Ritter.