Hyaline
membrane disease, also known as respiratory distress syndrome, is one of the most frequent causes of death in infants,
especially those who are born prematurely, have a low birth weight, or are delivered by Caesarean section. The symptoms of hyaline
membrane disease appear shortly after birth and can rapidly lead to death. The disease is a form of atelectasis, a collapse of the lungs or failure of the lungs to expand completely at birth. Hyaline membrane disease is thought to be caused by a lack of
surfactant, or surface-acting, material, which normally helps keep the lungs' alveoli (air sacs) expanded. If surfactant is lacking, surface tension exerts a contracting force on the alveoli, causing them to collapse. The disease takes its name from the hyaline, or glassy, membrane that sometimes forms in the air sacs of affected babies. In 1990 the U.S. Food and Drug Administration approved the use of a synthetic lung surfactant for infants with this disease.