A portrait in American fecundity: every day hundreds of young women, their bodies roundly pregnant, descend on the University of Southern California Women's Hospital. They overflow the available chairs and sprawl awkwardly on the floor. They come for prenatal checkups, gynecological care and, finally, to deliver their young. Last year more than 18,000 babies were born in this building, roughly 1 out of every 200 babies born in the U.S. "Sometimes they are lined up in the hallways and stacked up for C-sections like planes at LAX, six or seven deep," says obstetrician-gynecologist David Grimes.
But this busiest of U.S. obstetrics...