The endless debate over routine mammograms is getting another kick from an analysis that sharply questions whether the test really does what it's supposed to.
Dr. H. Gilbert Welch, coauthor of the analysis of mammography's impact, which was just published in The New England Journal of Medicine, tell Shots that the aim was to "get down to a very basic question."
Why people yawn is a mystery. But yawning starts in the womb.
Past studies have used ultrasound images to show fetuses yawning, but some scientists have argued that real yawns were getting confused with fetuses simply opening their mouths.
So Nadja Reissland, a researcher at the University of Durham in the United Kingdom, used a more detailed ultrasound technique to get images of fetal faces that could distinguish a true yawn from just an open mouth.