The other big factor that often determines when a child makes the move is the expected arrival of a new sibling. Extra care will be required if this is the reason for the transition, especially if the child likes her crib and hasn't shown any interest in getting out of it. This is a sensitive time for an older child and you don't want to make her feel as if she's being displaced, says Pamela High, MD, medical director of the Infant Development Center at Women and Infants' Hospital in Providence, Rhode Island.
If you need your toddler's crib for baby number two (or three), begin the process one to two months before the new baby is due to arrive, assuming that your toddler is at least 18 months old, says Dr. Widome. The idea is to get your older child comfortably situated in his new bed as far in advance as possible so that he thinks of the crib as neutral territory -- and not his sleeping spot -- when the younger sibling arrives. If possible, dismantle the crib or store it in a room where it's out of sight, suggests Dr. Widome. Or aim to make the crib "unsleepable" by filling it with stuffed animals, toys, and blankets.
Regardless of the reason for the switch, you'll ideally want to do it at a time when there are no other major changes going on in your child's life, says Dr. Widome. For instance, avoid making the move if your child is in the throes of toilet training, giving up a pacifier, or getting used to a new child-care arrangement.