What is infant respiratory distress syndrome?
Infant respiratory distress syndrome is a breathing disorder that is present at birth. Infant respiratory distress syndrome was previously known as hyaline membrane disease.
The disease is caused by a lack of lung surfactant, a chemical that normally appears in mature lungs. Surfactant keeps the air sacs from collapsing and allows them to inflate with air more easily. Normally, in the last months of pregnancy, cells in the alveoli produce a substance called surfactant, which keep the surface tension inside the alveoli low so that the sacs can expand at the moment of birth, and the infant can breathe normally. Surfactant is produced starting at about 34 weeks of pregnancy and, by the time the fetal lungs mature at 37 weeks, a normal amount is present.
In respiratory distress syndrome, the air sacs collapse and prevent the child from breathing properly. Symptoms usually appear shortly after birth and become progressively more severe. If an infant is born prematurely, enough surfactant might not have formed in the alveoli causing the lungs to collapse and making it very difficult for the baby to get enough air (and the oxygen it contains). Sometimes a layer of fibrous tissue called a hyaline membrane forms in the air sacs, making it even harder for oxygen to get through to the blood vessels. RDS in newborn infants used to be called hyaline membrane disease.
Infant respiratory distress syndrome almost always occurs in newborns born before 37 weeks of gestation. The more premature the baby is, the greater is the chance of developing RDS. RDS is more likely to occur in newborns of diabetic mothers. Respiratory distress syndrome affects 10% of all premature infants and only rarely affects those born at full-term.