Any Monday morning, until the freeze sets in, nurses at the windows of Helsinki's handsome, modern Children's Clinic can see a pint-sized (under 5 ft.), boyish-looking man step briskly up the drive with a 10- or 15-lb. pike slung over his shoulder. The fisherman is Dr. Arvo Ylppo, passing from his weekend avocation to his lifelong vocation. Ylppo, the only man in Finland to bear the proud title of archiater (chief physician, an honorific designation dating from ancient Greece), is the world's pioneering authority on premature babies.
When Ylppo began practicing 40 years ago, says a colleague, "doctors thought that prematures just...