What is ... Surfactant?

A key insight that led to helping premature babies survive involved bubbles. Specifically, it was the fact that soap in water reduces the pressure difference between the inside and outside of a bubble, and keeps it from collapsing.

When healthy babies are born their lungs pop open, and their alveoli (the millions of microscopic air sacs in which oxygen and carbon dioxide are exchanged during breathing) afterwards stay open, ready to receive air with each breath.

In the 1950s and '60s, despite the best efforts of doctors, many extremely premature babies died of respiratory distress syndrome, or RDS. Their lungs would open after birth, but their alveoli would close when the babies exhaled, and their lungs would become brittle and damaged,often collapsing.

What they lacked is pulmonary surfactant -- a natural soapy substance created by special cells in the alveoli of mature lungs that helps them, like a bubble, balance the pressure on their outside with their interrnal pressure, and remain open to incoming air.

In the 1980s, therapy using artificial surfactant was developed by March of Dimes grantee T. Allen Merritt, M.D., of the UC San Diego Medical Center. Since then, the number of babies who die from RDS has gone from 10,000 per year to fewer than 1,000.

Today, the introduction of artificial surfactant into the trachea and lungs of extremely premature newborns is essential therapy. Tens of thousands of babies born very prematurely have survived, most to grow up to have a chance to dip a wand into a bottle, put it to their lips, and ... blow bubbles.