Written by: Jenn Schoen, Certified Pediatric Sleep Consultant

Sleep training can be one of the most transformative steps parents take toward better rest, but it doesn’t always go smoothly. Many families start sleep training with the right intentions, only to feel confused or discouraged when progress stalls. The good news: most sleep training “failures” aren’t true failures—they’re simply signs that something in the sleep training approach, sleep environment, schedule, or bedtime routine needs adjustment.

This guide breaks down the six most common reasons sleep training fails, how to recognize them, and what you can do to get back on track.

1. Inconsistent Routines or Responses to Tears and Wakings

Consistency is the cornerstone of successful sleep training. Babies learn through patterns and repetition, and they feel safest when the same sequence of events happens every time they fall asleep. When bedtime routines or parental responses vary from night to night, it sends mixed signals about what’s expected. This inconsistency makes it significantly harder for babies to develop independent sleep skills because the “rules” keep changing.

Here are examples of common inconsistencies that often delay or derail sleep training results:

• Reverting to a sleep prop, like rocking, swaying, nursing, or bottle feeding during tough nights
• Using one method at bedtime and a different method for night wakings or at nap time
• Trying multiple sleep training approaches in rapid succession
• Extending bedtime routines—adding extra books, songs, rocking—when your baby protests or fusses, which can lead to overstimulation or overtiredness
  
  

Why Consistency in Sleep Training Matters

Inconsistency can delay and, in some cases, reset the learning process. Babies depend on predictable cues to understand what will happen when they’re tired or awake during the night. If the response changes from one waking to the next, they have no pattern to rely on. This uncertainty increases crying, lengthens settling times, and can create more night wakings—not fewer.

Tips for Staying Consistent During Sleep Training

Here’s how to avoid losing steam during sleep training, so you can 

• Choose a method you feel confident using consistently for up to two weeks, not just a few days. Remember: gentle sleep methods often require a high degree of parental involvement, so make sure you’re prepared to stick it out until the end.
• Stick with the same routine every night—same order, same length, same expectations. 
• Use the same method for naps and night wakings, so your baby clearly understands the pattern and can practice building their independent sleep skills under the same conditions.
• Prepare for the first few nights to be the hardest, and remind yourself that consistency in this window matters most.
• Communicate the plan with all caregivers so everyone responds the same way. Pro tip: if you’re feeling drained after a few nights, tag in your partner to take over for a night or two.
  
  

When the cues, routines, and responses are predictable, babies learn much more quickly—and sleep training becomes smoother and more effective.

2. Incorrect Wake Windows or Overtiredness

Even the most consistent sleep training method can fail if your baby’s daytime schedule isn’t aligned with their developmental needs. Sleep pressure builds gradually throughout the day, and when wake windows are too long—or naps are too short—your baby becomes overtired. An overtired baby doesn’t simply “crash.” Instead, their body releases cortisol, a stress hormone that increases alertness and makes it significantly harder for them to fall asleep and stay asleep. In other words, a misaligned nap schedule can completely derail even the best sleep training plan.

Common Signs Your Baby is Overtired

Babies don’t get drowsy when they’re overtired—they get wired. Look for these signs that your little one has pushed past their sweet spot:

• Your baby seems hyperactive or unusually clingy before sleep
• Long settling times at bedtime despite using the same consistent method
• Frequent false starts in the evening (waking 30–60 minutes after bedtime)
• Short, fragmented naps
• Early-morning wakings that don’t improve with night training
  
  

Why Preventing Overtiredness Matters for Restful Sleep

When babies are overtired, the brain signals the release of cortisol and adrenaline, which are designed to keep them alert and “powered through” exhaustion. These hormones can override your baby’s natural sleep drive, making it much harder to fall asleep and stay asleep—even if they’re extremely tired.

This is why the right nap schedule is so important. If your baby isn’t sleeping enough during the day or is awake for too long between naps, cortisol levels stay elevated, and the body struggles to transition into deep, restorative sleep at night. No sleep training method—not even the firmest—can counteract a chronically overtired state.

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How to Prevent Overtiredness in Babies

Think of preventing overtiredness as working with your baby’s biology, not against it. These steps make a big difference:

• Follow age-appropriate wake windows and adjust them as your baby grows
• Avoid pushing naps or bedtime too late, even if you’re tempted to “stretch” your baby in hopes of better sleep
• Watch for early sleep cues (rubbing eyes, yawning, fussiness, red eyebrows, or zoning out) and begin their sleep routine right away before overtiredness sets in
  
  

When daytime rhythms are aligned with your baby’s biological sleep needs, cortisol levels stay balanced, sleep pressure builds appropriately, and sleep training becomes far more effective—often with faster, smoother progress.

3. Sleep Props Are Still Present

Sleep props—anything your baby relies on to fall asleep—are one of the most common reasons sleep training stalls. These can include rocking, feeding to sleep, bouncing, swaying, using motion devices, or even repeated pacifier replacements. Sleep props aren’t inherently “bad,” but they become problematic when your baby depends on them to transition between sleep cycles. If these props are present at bedtime but not consistently maintained throughout the night, sleep training progress can slow or stop.

Here are common ways that sleep props can derail sleep training:

• You’re still rocking, patting, or feeding during certain wakings “just to help them settle”
• Baby relies on the pacifier for sleep but can’t replace it independently, leading to multiple overnight pop-ins
• Naps always require rocking or holding, even though independent sleep is expected at night
• Your baby can fall asleep in the crib but only after being soothed in your arms until drowsy
  
  

How Sleep Props Can Derail Sleep Training Progress

Babies expect the same conditions throughout the night that helped them fall asleep initially. If they fall asleep while being rocked or fed but later wake in a quiet crib without those conditions, they naturally signal for help. Even small inconsistencies—like rocking for naps but not bedtime, or helping “just once” during a long night—can reset progress and confuse the learning process.

What to Do To Remove Sleep Props

If sleep props have taken center stage:

• Remove or gradually reduce all sleep props, aiming for the same conditions at bedtime, nap, and night wakings
• Move your baby’s feeding to the beginning or middle of the bedtime routine and make sure you keep your baby awake during night feedings. Poppins certified pediatric sleep consultant Jenn Schoen says, “try tickling or squeezing your little ones feet during the feed to keep them awake until they’re ready to go back down into their crib.”
  
  

When sleep associations are aligned and consistent, babies settle more easily and naturally begin connecting sleep cycles with far fewer wakings.

4. Developmental Milestones or Regressions

Sleep training can temporarily stall when your baby is going through a major developmental leap. New skills, like rolling, sitting, crawling, or talking, can activate the brain in exciting ways, and babies often want to practice them everywhere, including at night. Regressions tied to rapid brain development, such as the 4-month regression or the 8–10-month regression, can also disrupt sleep patterns even when you’re following a consistent plan.

Here are common signs that your baby’s developmental leap may be slowing your sleep training progress:

• Your baby repeatedly practices new motor skills in the crib instead of settling
• Constant popping up to sit or stand, even when they’re tired
• Extra fussiness, clinginess, or separation sensitivity during the day
• Difficulty winding down for naps or bedtime
• More frequent early-morning wakings
  
  

Why Developmental Milestones Impact Sleep

New motor skills and cognitive skills temporarily compete with sleep pressure. A baby learning to roll or stand has an “itch” to practice, and the drive to master the skill can override the drive to sleep. Meanwhile, developmental milestones often come with sleep regressions—increased wakefulness, lighter sleep, and more frequent signaling (aka crying) for reassurance.

This isn’t a sign that sleep training isn’t working—it’s simply a reflection of your baby’s rapid growth and brain maturation.

What to Do When Your Baby Hits a Sleep Regression During Sleep Training

If your child is going through a sleep regression related to a developmental leap, we recommend holding off on sleep training until the regression has passed. Why? During these periods, your baby’s brain and body are working overtime, and adding the stress of learning new sleep skills can feel overwhelming.

But if you’ve already begun sleep training and a regression appears mid-process, here’s how to navigate it:

• Stay consistent with your chosen method, even if progress temporarily slows. Switching approaches during a milestone often leads to confusion and more tears
• Offer plenty of daytime practice for new motor or cognitive skills so your baby can master them outside the crib. Once a skill becomes automatic, it’s far less likely to disrupt sleep
• Increase connection during the day to help your baby feel secure and supported throughout the process
• Adjust expectations for a few days. Sleep usually dips during a regression, so be patient as you and your baby navigate this period

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Remember: developmental leaps are temporary, and most babies return to smoother, more predictable sleep once their new abilities settle into place.

5. Medical or Physical Factors Interfering with Sleep

Even the most consistent sleep training plan can fall apart if your baby is dealing with underlying medical or physical discomfort. Babies can’t verbalize pain or irritation, so disruptions in sleep are often one of the earliest signs that something isn’t quite right. When a baby is uncomfortable—whether from reflux, an ear infection, eczema flare, or congestion—the body’s natural sleep drive takes a back seat to the need for relief. In these situations, no sleep training method, no matter how well-structured, can override the physical discomfort your baby is experiencing.

Common physical factors that can impact sleep training include:

• Reflux or digestive discomfort
• Allergies or eczema
• Cough, cold or flu
• Ear infections
• Teething
• Snoring, mouth breathing, or labored breathing
  
  

Why it matters: If a baby is uncomfortable, they will wake more often and require more soothing, which can make sleep training feel inconsistent or ineffective. Babies experiencing pain, irritation, or illness simply aren’t in an optimal state for learning new sleep skills.

What to do: If your child becomes ill or is experiencing one of the medical symptoms described above, we recommend pausing sleep training and offering the comfort and care they need. Once your child is fully recovered, you can resume your sleep training plan, and most babies return to progress quickly once they’re feeling well.

6. Intervening Too Quickly When Your Child Stirs

During sleep training, one of the most important things you can do is pause for three minutes when your baby wakes and cries. Why? This brief window gives your baby the chance to try resettling on their own before you help—the core skill sleep training is designed to build.

Here’s why the 3-minute rule helps:

• Creates space for learning: Babies often make small self-settling attempts that get interrupted if you enter too quickly.
• Prevents mixed signals: Immediate intervention can reinforce the idea that they need help to fall back asleep.
• Supports consistency: A predictable pause helps babies understand what to expect during night wakings.
  
  

When your baby wakes during the night, here’s how to respond using the 3-minute rule:

1. Wait three minutes before going in. Set a timer if you need to.
2. Observe for signs of settling (pauses, shifting, quieter fussing).
3. If after three minutes, your baby is not showing any signs of settling, go in to soothe them and apply whatever sleep training method you used at bedtime.
   
   

Most babies show progress quickly once they are consistently given this short window to practice their independent sleep skills.

How to Know Sleep Training Is Working

Sleep training doesn’t always move in a straight line—some nights feel easier, others more challenging—but steady progress usually appears in small, predictable ways. These early signals often show up before your baby is fully sleeping through the night, and noticing them can help you stay confident during the learning curve.

Look for these early signs that sleep training is working:

• Decreasing settling time. Your baby begins falling asleep more quickly at bedtime, with less crying, fussing, or needing your support to drift off.
• Fewer night wakings. Instead of fully waking and calling for help during each sleep cycle, your baby starts resettling independently more often.
• Longer stretches of continuous sleep. You may notice your baby consolidating nighttime sleep into longer chunks—4, 5, or even 8 hours depending on age and feeding needs.
• Calmer daytime behavior. Well-rested babies tend to be more alert, social, and emotionally regulated, with fewer overtired meltdowns or “witching hour” struggles.
• More predictable naps. Daytime sleep becomes easier to initiate and more consistent in length, which supports smoother bedtimes and better overnight sleep.
  
  

Most families notice at least some of these improvements within the first week, especially when the sleep training method is developmentally appropriate and applied consistently. Over the following days, these early wins typically build into more consolidated, restorative sleep for the whole family.

FAQ: Why Doesn’t Sleep Training Work?

When sleep training isn’t going as planned, it’s easy to feel confused, discouraged, or unsure of what to change. The truth is, most setbacks have simple, fixable explanations—and they’re far more common than parents realize. This FAQ section answers the questions families ask most often when sleep training feels “stuck,” helping you identify what’s getting in the way and how to get sleep back on track with confidence.

Why Isn’t My Baby Falling Asleep Even with Sleep Training?

Common causes include overtiredness, inconsistent routines, or sleep props still being used. Adjusting wake windows and ensuring consistency usually helps.

How Long Should I Try a Method Before Deciding It’s Not Working?

Most methods should be followed for at least 3–5 nights before evaluating effectiveness, unless you suspect discomfort or illness.

Does Sleep Training Fail for Some Babies?

Yes, but usually because something in the environment or routine needs to be adjusted—not because the baby can’t learn independent sleep skills.

Can Teething or Illness Cause Sleep Training Setbacks?

Absolutely. Pause training during illness or significant discomfort, then restart once your baby is well.

Do Some Babies Need a Gentler or Slower Approach?

Yes. Young babies (under 6 months) and sensitive or high-alert babies often benefit from gradual methods with more parental presence.

Need Help Troubleshooting Sleep Training? Poppins Can Guide You

If sleep training feels overwhelming—or you’ve tried and haven’t seen the results you hoped for—you don’t have to figure it out alone. Poppins offers:

• Personalized sleep plans tailored to your baby
• Real-time coaching for hard moments
• Guidance that aligns with your parenting style
  
  

We’ll help you understand what’s going on, make adjustments that work, and support you every step of the way.

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