Putting babies to sleep on their backs was common in many societies until the early 20th Century, when many U.S. doctors started to promote the opposite.
Believers in stomach sleeping, including Dr. Benjamin Spock, preached that prone sleeping could prevent babies from choking on their own vomit or developing pneumonia caused by inhalation of vomit or foreign objects.
Decades of that message made it difficult to change sleep practices once studies found that back sleeping reduced the incidence of sudden infant death syndrome by more than 50 percent.
In 1992, federal officials estimated that only 13 percent of babies slept on their backs. Thanks in part to a “Back to Sleep” campaign that started in 1994, that figure increased to 73 percent by 2003.
Today, virtually all medical authorities agree that children should be put to sleep on their backs.
