For some families, implementing this sleep training method can help baby learn to sleep through the night.

“Sleep when the baby sleeps,” they say. But what if yours doesn’t seem too keen on sleeping at all?

Well, you’re not alone. There are a multitude of parenting books written specifically about sleep training methods, some of which involve letting your baby cry for periods of time.

While it can sound harsh, the idea behind crying it out, as it’s called, is that a baby can learn to soothe themselves to sleep versus relying on a caregiver to soothe them. And self-soothing may lead to solid and more independent sleep skills over time.

Let’s take a closer look at the cry-it-out method so you can determine if it’s something you want to try.

“Cry it out” (CIO) — or sometimes “controlled crying” — is an umbrella term used to describe several different methods that involve letting a baby cry as they learn to fall asleep on their own.

You may be familiar with the Ferber Method, for example, which has parents set specific time increments to check on baby if they’re crying — but there are several other sleep training programs that involve varying degrees of CIO.

Weissbluth’s method

In this method, Marc Weissbluth, MD, explains that babies may still wake up to two times a night at 8 months old. However, he says parents should start predictable bedtime routines — letting babies cry 10 to 20 minutes to sleep —- with infants as young as 5 to 6 weeks of age.

Then, when baby is 4 months old, Weissbluth recommends doing what’s called “full extinction,” which means allowing them to cry until they stop/fall asleep without parent interaction/checks.

Murkoff’s method

Heidi Murkoff explains that by 4 months of age (11 pounds), babies no longer need night feeds. This also means they can sleep through the night — and that night waking after 5 months old is a habit.

Sleep training — graduated extinction, scheduled awakening, reinforcement of sleep rhythms — begins after 4 months old as chosen by the parents. At 6 months, Murkoff says that “cold turkey” CIO is appropriate.

Bucknam and Ezzo’s method

Robert Bucknam, MD, and Gary Ezzo — who gave their book “On Becoming Babywise” the subtitle “Giving your infant the gift of nighttime sleep” — feel that teaching your little one to self-soothe is truly a gift that will help baby in the long run. Ezzo and Bucknam say that babies between 7 and 9 weeks of age are capable of sleeping up to 8 hours a night. By 12 weeks, this increases up to 11 hours.

The CIO method here involves allowing 15 to 20 minutes of crying before sleep. It’s also important to note that this method prescribes a specific rhythm of daytime sleep as well (eat-wake-sleep).

Hogg and Blau’s method

“Baby whisperer” Tracy Hogg and Melinda Blau say that by the time a baby weighs 10 pounds, they’re ready to sleep through the night. That said, they recommend cluster feeding in the evenings and doing a dream feed.

With regard to CIO, the authors say that babies will do three “crescendos” of crying before sleep. Parents tend to give in during that second peak. In this method, parents are permitted to respond — but encouraged to leave again immediately after baby settles.

Ferber’s method

Likely the best known CIO method, Richard Ferber, MD, uses the graduated extinction model starting when baby is 6 months old. “Graduated” basically means that parents are encouraged to put baby to bed when they’re drowsy but still awake.

Then, you’re to let your baby cry for 5 minutes before responding the first time. After that, you may extend the time between responses by 5- (or fewer) minute increments.

Giordano and Abidin’s method

Suzy Giordano and Lisa Abidin believe babies are capable of sleeping 12 hours at a time without a night feed by 12 weeks of age. Once a baby reaches 8 weeks old, this method allows crying at night for 3 to 5 minutes before you respond. Instead of night feeds, the authors encourage parents to feed babies every 3 hours during the day.

For more information

Shop online for books about these CIO methods:

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How you go about CIO depends on your baby’s age, the philosophy you follow, and your sleep expectations. There’s no one-size-fits-all approach, and what works for one baby or family may very well not work for another.

Before sleep training using CIO, you may want to speak with your child’s pediatrician to get clarification on how much your baby should be sleeping at night for their age, whether or not they need a night feed, and any other concerns you might have.

Here’s a sample way to start CIO:

1. Establish a predictable nighttime routine

Many parenting experts agree that before CIO, you should get your child into a bedtime rhythm. That way, your baby is able to start relaxing and gets cues that it’s time to sleep. This might involve things like:

2. Place your child in their crib

But before you leave the room, make sure to practice safe sleep practices:

  • Don’t practice CIO with a baby who is still swaddled.
  • Make sure the crib is clear of any stuffed animals or pillows.
  • Place your baby on their back to sleep.

3. Watch and wait

If you have a video or audio baby monitor, tune in to see what your child is up to. In some cases, they may go to sleep. In others, there could be some fussing. This is where your specific method comes in as to how you respond:

  • If you’re following full extinction, you should still keep an eye on your child to make sure they’re safe.
  • If you’re following a graduated approach, be sure to keep track of the different intervals as you go to briefly soothe your child.

4. Soothe, but don’t linger

For example, if you’re following the Ferber Method:

  • The first night, you would go in after 3 minutes, then again after 5 minutes, and then again after 10 minutes.
  • The second night, the intervals might be more like 5 minutes, 10 minutes, 12 minutes.
  • And the third night, 12 minutes, 15 minutes, 17 minutes.

Each time you go in, simply pick your baby up (or not — it’s up to you), assure them, and then leave. Your visit should be 1 to 2 minutes, tops.

5. Consider other situations

Sometimes, cries are your baby’s signals for help.So, there are times when your baby is more likely to cry and actually needs you. If your little one is really having a hard time, take a step back and evaluate the bigger picture:

There are a number of reasons your baby may cry and actually need your help.

6. Be consistent

It may be hard to keep up CIO night after night if you feel your efforts aren’t immediately working. Eventually, your baby should get the idea.

However, to get there, it’s very important to try to stay consistent and follow the plan. Responding at certain times and not others can be confusing to your baby.

Related: Should you let your child cry it out at naps?

Whether you follow a full extinction or graduated extinction CIO plan, there gets to be a point where you might wonder: How long should I let my baby cry? Unfortunately, there’s really no single answer to this question.

Nicole Johnson, sleep expert and author of popular blog the Baby Sleep Site, says that parents should have a clear plan before starting.

The goal of CIO is to have a baby fall asleep without sleep associations, like being rocked by mom or dad. So, it’s tricky, since going in to check on baby might involve rocking or other sleep associations.

Johnson says that parents need to decide together what’s “too long.” Instead of waiting for what feels “too long” in the moment, try to work out the details ahead of time.

And she also says to be aware of situations where a baby’s long spells of crying may actually signal that the baby needs help (illness, teething, etc.).

Related: Your baby’s sleep schedule in the first year

Experts share that while various methods state you can start CIO as early as 3 to 4 months old (sometimes younger), it may be more developmentally appropriate to wait until your baby is over 4 months old.

Some CIO methods go by a child’s weight as a recommendation on when to start. Others go purely by age.

Whatever the case, it has to do with development and different ideas about when a baby needs night feedings versus when they’re ready to go without them. (Also, how you define “going without a night feeding” matters. There’s a big difference between going 6 to 8 hours without a feeding and going 12 hours without.)

The following table displays the age that different methods say parents can start things like “cold turkey”, “extinction”, or “graduated extinction” CIO with babies.

MethodStarting age / weight
Weissbluth4 months old
Murkoff6 months old
Ezzo and Bucknam1 month old
Hogg and Blau6 weeks / 10 pounds
Ferber6 months
Giordano and Abirdin8 weeks

It’s a good idea to speak with your pediatrician before starting any CIO program, as your baby may have specific health or feeding needs not addressed by parenting books.

As with all things parenting, try your best to not go too much by the book and to look at your individual child’s needs.

Related: 5 tips to help your baby sleep through the night

You probably have a friend or family member who absolutely swears that CIO was their ticket to nighttime sleep success. Well, if you’re still a bit leery of this method, there’s some good news: A 2016 study focused on the emotional effects of letting babies cry. The results didn’t show any long-lasting trauma.

It’s important to point out that the study specifically looked at sleep training methods that involve graduated extinction, where parents do respond to cries in set intervals.

To perform the research, the scientists measured the babies’ cortisol (the “stress hormone”) levels using their saliva. Then, 1 year later, the babies were evaluated for things like emotional/behavioral problems and attachment issues. The researchers didn’t find a significant difference in these areas between babies in the test and the control groups.

The researchers also evaluated whether or not CIO methods actually lead to better sleep. Again, the answer was positive. The babies who cried actually fell asleep faster and had less stress than babies in the control group. The CIO babies were also more likely to sleep through the night than the control group.

While this is just one sample, a 2012 study evaluated long-term effects of sleep training. The results were similar. Five years after sleep training, researchers determined that such intervention had no negative effects — and there was no difference between the test and the control groups.

As you can imagine, the idea of letting a baby cry for periods of time without parental involvement does get some heat from critics. But is there research to support the idea that crying can be damaging to babies?

One study suggested that babies become more securely attached to their mothers when nighttime interactions are positive — that is, when mom (or dad, presumably, although the study looked at mothers) picks up and soothes baby if they wake up crying.

Psychologist Macall Gordon explains that popular sleep training methods seem to take a stance that the ability to sleep longer stretches is linear, meaning that the amount your child sleeps at night should increase with time.

However, she points out that sleep may actually be tied to things like:

  • brain growth
  • your individual child’s temperament or physiology
  • culture and developmental regressions in the first year

In other words: Sleep isn’t cut and dry, and there isn’t necessarily a specific plan — involving crying or not — that will get your baby reliably sleeping 12 hours each night.

Related: Does the pick up, put down method work to get your baby to sleep?

You can work on better sleep habits with your baby without subscribing to any specific method of sleep training. Some tips:

  • DO keep a consistent bedtime routine each night and place your baby in their crib drowsy but awake.
  • DO let your baby fuss a bit and consider using a pacifier to help them settle.
  • DO work to understand what’s developmentally appropriate to expect from your child when it comes to night wakings/feedings.
  • DON’T fret if the methods you’re trying aren’t working.

Some babies are born good sleepers. For others, it’s a process that can take some time. If you have concerns about your baby’s sleep habits, don’t hesitate to make an appointment with your pediatrician.