I am waiting until DS turns 2. I randomly asked my pedi one time and she said not until 2 even before I told her that's what I was planning. I know I'm among the minority here...
We used to wrap one around DD's waist when she was in RNP and she refused to transition to the crib without it, so when we transitioned at around 7 months she had the blanket in the crib.
We wanted to wait until he was 12 months, but he is a January baby and at about 11 months the 0-9 sleep sacks stopped fitting him. So 11 months is when we did it.
Re: blanket
DS1 2-26-07
#4 Due May 2015
IT'S A BOY
I put one in at 1 year
Freshie Girl 9.29.12