Low Birth Weight
An important component of decreasing infant mortality is to prevent LBW. The rate of infant death increases significantly with decreasing birth weight for infants weighing less than 2,500 grams. As previously explained, LBW is a risk factor for SIDS. It is also a leading cause of infant mortality on its own in the United States. LBW is often caused by prematurity. In 2001, 11.6 percent of live births were born too early, or prior to the 37th week of pregnancy, and 7.6 percent were born too small, weighing less than 2,500 grams or 5.5 pounds.
Respiratory Distress Syndrome
Respiratory Distress Syndrome (RDS) occurs primarily in infants born too early and is a result of lungs that are not fully developed. The lungs of a full-term baby contain a foamy fluid known as surfactant. Surfactant helps the air sacs, or alveoli, in the lungs expand in order to let in air. Because of their early birth, premature babies’ lungs have not yet developed surfactant. Without surfactant, a baby’s lungs cannot inflate properly and the baby will have difficulty breathing.