Thousands of women suffer life-altering injuries or die during childbirth because US hospitals and medical workers skip safety practices that are known to prevent problems. Doctors and nurses should be weighing bloody pads to track blood loss so they recognize danger sooner. They should be giving medication within an hour of spotting dangerously high blood pressure to fend off strokes.

One exception in the U.S.: California, where safety experts and hospitals worked together to implement practices that are now endorsed by leading medical societies as the gold standard of care. Statewide, California's maternal death rate has fallen by half, while deaths rose across most of the country.

Despite widespread recognition that the California safety measures save lives, hospitals elsewhere have been slow to use them.