The answer is called the foramen ovale. Hope this helps.
It may be perfectly healthy that their newborn is sleeping this long so unless they start displaying other strange symptoms that cause concern, there is no need to worry. They could suggest that they are concerned to the midwife if they feel anxious, to get a professional opinion.
<span>There are three major groups of mammals, categorized on the basis of their method of reproduction. Monotremes lay eggs to have children instead of having the mother bear them. The second type of mammal is the marsupial, which are non-placental animals who carry their young in their pouches. Eutherians are the third group who are placental mammals.</span>