For my wife and me, those early days passed in a blur. Nights seemed endless, and no government ordinance was about to come along to shorten our shifts. When he was around 3 months old, our son started sleeping for longer periods and our relief was profound. But after about a month, the baby started waking up at night again. After one nightly waking became two, then three and four, I realized it was time to sleep train our son.
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.
"I have a 5 1/2-month-old baby girl who has never once in her life "cried it out." From night one in the hospital, she has slept with me. She is rocked and nursed to sleep and when she starts to grunt/wiggle beside me, I simply shift near enough for her to latch on to my breast, and she nurses back to a deep sleep before either of us fully wakes. I follow Dr. Sears' attachment style parenting and my baby has never once in all her life cried during the night or even fully woken up."
"There are good times to sleep-train and periods when it may be less likely to work," says developmental psychologist Isabela Granic, Ph.D., coauthor of Bed Timing: The 'When-To' Guide to Helping Your Child to Sleep. "This is because infants and toddlers go through mental growth spurts that make them especially clingy, fussy, and prone to night wakings. They're learning new cognitive skills and often don't sleep as well."
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.