Credit: Melissa Bates
In 1963, President John Kennedy’s wife, Jackie, gave birth to a little boy three weeks early. The baby survived only 39 hours before dying of hyaline membrane disease, more commonly known as respiratory distress syndrome. The first successful treatments began in 1991, and now nearly 99 percent of babies like the Kennedy baby survive prematurity. Physicians are even able to treat babies born as much as 16 weeks early. This also means that the first large-scale group of people with hyaline membrane disease to survive being born prematurely is only 24 years old. What does the future hold for this population?
Hyaline membrane disease is caused by a deficiency in the molecule surfactant. Surfactant is produced in the lung starting shortly before birth and is critical for the lungs to inflate and the lungs’ surface to stay dry. To treat the disease, premature babies are given surfactant derived from animals. In addition to surfactant, supplemental oxygen is given and babies are placed on mechanical ventilators.
We recently found that adults who had been born prematurely had important, but unexpected, changes in their physiology. For example, unlike their peers who were born at full term, prematurely born adults couldn’t increase their breathing in a low-oxygen environment. We also discovered that their exercise capacity and the ability of their lungs to take up oxygen were reduced. We were really struck by this because these prematurely born adults looked just as healthy as adults born at term, until they were stressed with exercise or a low-oxygen environment.
Although we studied minor stresses in a healthy population, we think that our experiments offer a clue that a bigger problem exists on the horizon. Soon, this young population will begin to age. We’ve already found that their physiology is different. Given the current success in treating premature infants now, it is absolutely vital that we shift some of our scientific focus to figuring out whether their different physiology puts them at higher risk of age-related diseases, such as high blood pressure, pulmonary hypertension and diabetes, in the future.
Melissa Bates, PhD, is an assistant professor of human physiology at the University of Iowa.
Correction (10/22/15): An earlier version had said that the baby was born in 1967. The correct year was 1963, and the post has been revised.