Respiratory distress syndrome (RDS) occurs most often in infants who are born too early. RDS can cause breathing difficulty in newborns. If it is not properly treated, RDS can result in complications. This may include pneumonia, respiratory failure, chronic lung problems, and possibly asthma. In severe cases, RDS can lead to convulsions and death.

Respiratory System of an Infant  
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RDS occurs when infant's lungs have not developed enough. Immature lungs lack a fluid called surfactant. This is a foamy liquid that helps the lungs open wide and take in air. When there is not enough surfactant, the lungs do not open well. This will make it difficult for the infant to breathe.

The chance of developing RDS decreases as the fetus grows. Babies born after 36 weeks rarely develop this condition.


Risk Factors  

A risk factor is something that increases your chance of getting a disease or condition. Factors that increase your baby's risk of RDS include:

  • Birth before 37 weeks; increased risk and severity of condition with earlier prematurity
  • Mother with insulin dependent diabetes
  • Multiple birth
  • Cesarean section delivery
  • Cold stress
  • Asphyxia
  • Precipitous delivery
  • Previously affected infant
  • Being male
  • Hypertension (high blood pressure) during pregnancy


The following symptoms usually start immediately or within a few hours after birth and include:

  • Difficulty breathing, apnea
  • Rapid, shallow breathing
  • Delayed or weak cry
  • Grunting noise with every breath
  • Flaring of the nostrils
  • Frothing at the lips
  • Blue color around the lips
  • Swelling of the extremities
  • Decreased urine output


The doctor will ask about the mother's medical history and pregnancy. The baby will also be evaluated, as outlined here:

Before Birth  

Amniotic fluid is fluid that surrounds the fetus. It may be tested for indicators of well-developed lungs such as:

  • Surfactant
  • Lecithin:sphingomyelin ratio
  • Phosphatidyl glycerol

After Birth  

  • Laboratory studies—done to rule out infection
  • Physical exam—includes checking the baby's breathing and looking for bluish color around the lips or on trunk
  • Testing for blood