The cause of respiratory distress syndrome in premature infants is

The cause of respiratory distress syndrome in premature infants is lack of surfactant in the lungs because the lungs has not fully developed.

Explanation:

Respiratory distress syndrome is a type of neonatal disease of respiration caused by the lack of surfactant production by the lungs.

Normally the lungs of fetus start the formation of surfactant during the third trimester of pregnancy (26 weeks through labour and delivery). The surfactant is produced by type II alveolar cells and is the lipoprotien complex that has surface tension lowering effect (surface active agent) having both hydrophobic and hydrophilic properties thus coats the air sacs and alveoli.

In the premature infants, the lungs are not fully developed hence the adequate amount of surfactant is missing thus resulting in Respiratory distress syndrome.