Question: how long baby can sleep in the crib?
Answer: Over 90% of 18-month-olds sleep in a crib, but that gradually drops to about 80% at 2 years and 40% by 3 years of age. After the first birthday, it's wise to put the mattress all the way down and make sure your tot doesn't have toys or bumpers to climb on. The top of the crib rail should be above his collarbones.