Most sleep coaches say the ideal time to start sleep training (or promote independent sleep, not necessarily using the cry-it-out method) is based on your baby’s development, but is usually somewhere between four and six months, when your baby hasn’t had much time to get used to nursing or rocking to sleep. At this stage, most babies are also developmentally ready to learn the skill of falling asleep on their own, explains Jennifer Garden, an occupational therapist who runs Sleepdreams in Vancouver. Around four months of age, some babies go through a sleep regression because their sleep cycles change and there are longer periods of lighter sleep per cycle. “It’s a great time to work on independent sleep skills,” says McGinn. Other babies’ slumber derails around this time because they are working on new skills, like moving around and rolling. Some parents choose to wait until things settle down before embarking on a sleep-training method, but you don’t have to, says McGinn.
Though many of the parents I see in clinic have put up with terrible sleep for years, sleep training is a safe and effective tool to help babies learn to soothe themselves at night. For this guide, I reviewed the literature on infant sleep. As director of the Pediatric Sleep Center at Yale University, I have extensive experience helping families to address sleep problems. I have also written a book on the topic, which was inspired by sleepless nights with my own children.
"A young child cannot yet understand what is best for him, and he may cry if he does not get what he wants," Ferber writes. "If he wanted to play with a sharp knife, you would not give it to him no matter how hard he cried, and you would not feel guilty or worry about psychological consequences. Poor sleep patterns are also harmful for your child and it is your job to correct them."
If your baby is older than six months, don’t worry, McGinn says: “It’s never too late to develop good sleep habits.” Dickinson says he finds nine months to be a bit of a sweet spot for parents in terms of getting babies to sleep through the night. “They are at a good age for understanding routines and don’t need to eat during the night,” he explains.