What a difference a century makes!

At the beginning of the 20th century, pregnant women put their affairs in order and kissed their families with fervor before they went into labor, knowing they might not survive their "travail."

A decade into the 21st century, birth has become so safe in industrialized countries that we tend to take that safety for granted. The vast majority of women sail through birth without a hitch.

In addition, women who 100 years ago could not have hopefully embarked on a pregnancy -- women with diabetes, for example -- now are able to bear children with careful monitoring.

Some women do still encounter problems that can be life-threatening, however, and it's not always possible to predict which women those will be.