"It also keeps the baby in lighter phases of sleep so he can practice arousing and going back to sleep, which is good in case of any problems, such as sleep apnea."
Being close to their parent regulates a baby's heart rate, immune system, and stress levels, and makes breastfeeding easier, says James McKenna, Ph.D., director of the Mother-Baby Behavioral Sleep Laboratory at the University of Notre Dame in Indiana. "It also keeps the baby in lighter phases of sleep so he can practice arousing and going back to sleep, which is good in case of any problems, such as sleep apnea."