Most experts recommend starting when your baby is between 4 and 6 months old. By about 4 months, babies have typically started to develop a regular sleep-wake cycle and dropped most of their night feedings. These are signs they may be ready to start sleep training. Many babies this age are also developmentally able to sleep for long stretches at night.
If your baby is growing poorly or is difficult to console, you should talk to your child’s pediatrician to ensure that your child’s sleeping difficulties have no medical cause. Likewise, if you are struggling with depression, it is critical to discuss this with your child’s pediatrician as well as your own physician. Poor sleep can prolong postpartum depression in mothers.
Parents often wonder how to know if your child needs sleep training or if their sleep habits are just something they’ll grow out of. If your baby is consistently cranky and overtired, it's probably time to look into helping them become a better sleeper. And as Melissa noted, she started sleep training the second time around because she could tell her son was just as frustrated as she was about not sleeping!
Some of these experts think cry it out methods are not good for babies. Pediatrician and "attachment parenting" advocate William Sears devotes an entire chapter of The Baby Sleep Book to a critique of cry it out approaches. Sears, along with no tears advocates such as Elizabeth Pantley (author of The No-Cry Sleep Solution), believes that cry it out techniques can give your child negative associations with bedtime and sleep that could last a lifetime.
Some experts suggest techniques that are slightly different than these methods. Perhaps the best known is pediatrician Harvey Karp, author of The Happiest Baby on the Block. His method suggests a very specific routine involving the so-called five S's: swaddling, the side or stomach position (for calming your baby, not for sleeping), shushing, swinging, and sucking.
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.
The idea behind extinction (or full extinction to differentiate it from graduated extinction) is that you want to extinguish the behaviour (crying) by not responding to it. As with the check-and-console method, go through your bedtime routine, put them in their crib awake, say good night and walk out. This is certainly the most controversial sleep-training method, and even experts disagree on what you should do next—it all depends on what stage your baby is at developmentally, as well as what works for the parents.