Many babies born prematurely have not yet started making surfactant. Surfactant is a substance that helps keep the lungs open when we breathe. Babies who have RDS need oxygen and need help with their breathing until the lungs make surfactant. A ventilator is used for 5 to 7 days to help the baby breathe. The baby is given artificial surfactant to to help him breathe until the lungs make their own surfactant.
Apnea occurs because the brain is still immature.
It improves as the brain matures. In the meantime the baby is given help to keep breathing. Sometimes the baby is placed on a respirator, which breathes for her until she is able to breathe more reliably. Babies who are born 12 weeks or more prematurely may not breathe reliably for several weeks. Many very preterm babies develop chronic lung problems.