What to Expect When You're Expecting is a pregnancy guide, now in its fifth edition, written by Heidi Murkoff and Sharon Mazel and published by Workman Publishing. Originally published in 1984, the book consistently tops The New York Times Best Seller list in the paperback advice category, is one of USA Today's "25 Most Influential Books" of the past 25 years and has been described as "the bible of American pregnancy".

Incorporating everything that's new in pregnancy, childbirth, and the lifestyles of parents-to-be, complete with a preconception plan, information on choosing a practitioner, birthing alternatives, second pregnancies, twins, making love while pregnant, and coping with common and not so common pregnancy symptoms.