Under normal circumstances, newborn babies can sleep flat on their backs just after birth, and there is no special adverse effect on the child. The newborn baby, due to physical development is not perfect, will not turn over, so the vast majority of the time is to take the flat position to sleep. And newborns lie flat, the muscles on both sides of the body are evenly stressed, so sleep more relief, the child will sleep more deeply. But parents need to be careful not to let the child lie flat when feeding, so as not to cause vomiting. In addition, when the child has a cold, coughing, coughing symptoms or the presence of severe gastric reflux and frequent spitting up, lying down to sleep is likely to cause aspiration pneumonia, or even asphyxiation, it is better to choose the side sleep position. When the child sleeps flat for a long time, parents can properly turn over for it and change the sleeping position to avoid abnormalities in the baby’s head, affecting the beauty.