This segment originally aired on September 20, 2013. An edited version was included in a best-of Brian Lehrer Show episode on December 26. The audio from the original segment is posted here.

Emily Oster, economics professor at the University of Chicago and author of the new book Expecting Better: Why the Conventional Pregnancy Wisdom is Wrong - and What You Really Need to Know, discusses her book where she challenges rules about pregnancy and offers her own advice based on her examination of the data.