The Science of Mother-Infant Sleep is a compilation of recent articles that address these important questions. Our goal was to bring together recent evidence about the safety of sleep practices so that parents and professionals can make informed, evidence-based decisions. The Science of Mother-Infant Sleep is a collaborative project by an international working group of experts on mother-baby sleep. • Sleep-Training and Cry-It-Out Techniques • Do they impact infant health and development? • What should parents know? • Parental Decisions about Infant Sleep • What is normal infant sleep? • How can parents calm a crying baby?