Sleep training is one of the most polarizing topics in new parenthood. But many people do swear by it?like a friend of mine who had the date she was going to start sleep training her second child circled on the calendar shortly after he was born. 
This raises the question: If you?re planning on sleep training, when exactly should you do it"  Most parents do it between four and nine months, and yet, some parents online are sharing that they?ve done it earlier?much earlier, when their babies are just eight-weeks-old. Is that okay" We asked the experts to find out.
Can I sleep train my baby at eight weeks" 
Not really, says Sanjeev Bhatla, a member of the Canadian Paediatric Society?s Early Years Task Force and a family physician based in Calgary. Eight weeks is simply too young, he says. ?I think if you asked the other members of the Early Years Task Force, they would universally say no, that?s too early,? he says.   Elizabeth Murray, a pediatrician and spokesperson for the American Academy of Pediatrics, agrees. ?They?re not developmentally meant to do it at that age?and they still need the calories from eating at night,? she says. 
What is the youngest age you can sleep train a baby" 
There?s no hard and fast rule, but almost all of the research that supports sleep training has been done on babies who are six months old. ?There?s good evidence that once babies are six months old, it doesn’t do any harm to attachment, and even five years later...