New Born is always kept on the left hand side of the mother

I was watching a movie day before. There was a particular scene in which a child is born and after a few scene cuts, the child is crying laying on the left side of the mom. It just triggered a thought as to why a child when born is put on the left hand side of the mom. Though this has crossed my mind many a times, but i have never taken the pains to find out why it was the case. Day before, my intellect forced my mind to look into this.

Well the reason is quite simple. A child when kept on the left hand side sleeps peacefully and is in sound mind. When a child is inside mother's womb, it keeps on hearing the heartbeats of his/her mom. Even if there is a slight increase or decrease in the number of beats, then it sends out the danger signal to the child and the child starts feeling uncomfortable. When a child is born, it needs to hear the same beats in order to be in peace.

This is definitely not mine, Who else can i get the information from......