It’s okay if you’re not ready. You aren’t missing out on sleep training if you skip it at 4 months: You truly can start sleep training at any age, even in the toddler years, although experts say it’s smart to be aware of developmental milestones and adjust baby’s sleep schedule accordingly. For example, the week baby learns to walk may be tough to implement a sleep-training schedule, and even a sleep-trained baby may see a regression simply because he’s going through such a developmental shift.
The age of your baby might determine what kind of sleep-training method you choose, though. You could try a gentle shush-pat technique with a five-month-old, but you’ll likely have to leave a one-year-old in the crib as they protest (cry or scream) about the new bedtime arrangement. Don’t attempt a formal sleep-training method before four months, until your baby is able to go longer in between feeds and their circadian rhythm starts to develop. (Many babies this age still feed in the night—contrary to popular thinking, sleep training isn’t synonymous with night weaning.) Dickinson says that many four-month-old babies are biologically able to go through the night without a feed, but that doesn’t mean you shouldn’t respond and feed them if other methods of calming them aren’t working. Since every situation is different, we recommend checking with your doctor before withholding your baby’s night-time feeds.