Here’s the thing about baby sleep: everyone has an opinion, and most of them contradict each other. “Let them cry—it builds independence.” “Never let them cry—it damages attachment.” The reality is less dramatic. Multiple approaches work. The question isn’t which method is “best” but which one you can actually stick with.
A 2016 randomized controlled trial followed two groups of babies through age six. One group did graduated extinction (Ferber). One group did bedtime fading (gradual reduction of parental help). Both groups had improved sleep. Neither group showed negative effects on attachment or emotional development. What didn’t work was inconsistency—families who tried a method for two days, gave up, tried another, gave up.
This guide covers the main approaches, when to start, and what actually matters.
When to start
Most pediatricians recommend waiting until 4-6 months. Before that, babies are still figuring out day and night, still need frequent feedings, and don’t have the neurological maturity for self-soothing. The Cleveland Clinic and the American Academy of Pediatrics both suggest this window.
That said, there’s nothing magical about 4 months. Some 5-month-olds aren’t ready. Some 3-month-olds sleep 8-hour stretches without any training. Your baby’s actual readiness matters more than the calendar.
Signs your baby might be ready:
- They’ve started self-soothing (thumb-sucking, finding their hands)
- They occasionally sleep 5+ hours at night already
- You have a bedtime routine in place
- No major health issues
Don’t start if: baby was premature (adjust age first), has reflux that’s being treated, is going through a growth spurt or illness, or you have a major life change coming up (moving, travel, new caregiver).
The 4-month regression
Around 3-4 months, babies who were sleeping well often suddenly… stop. This is the infamous 4-month sleep regression, and it’s actually a developmental milestone. Your baby’s sleep cycles are changing from newborn patterns (basically “sleep” and “not sleep”) to more adult-like stages with light sleep, deep sleep, and REM.
The result: they wake up more. A 30-minute nap becomes 20 minutes. A 5-hour stretch becomes every-90-minutes.
This is exhausting, but it’s also temporary—usually 2-3 weeks. And paradoxically, it can be a good time to start sleep training, since your baby is already learning new sleep patterns.
The methods
There’s no perfect method. Each one works if you do it consistently. Each one fails if you don’t. Here’s what each involves.
Ferber (Graduated Extinction)
The most researched method. You put baby down awake, let them cry for set intervals, check in briefly, and gradually extend the intervals each night.
Night 1: Check after 3 minutes, then 5 minutes, then 10 minutes. Night 2: Check after 5 minutes, then 10 minutes, then 12 minutes. Night 3 and beyond: Continue extending.
During check-ins, you go in, pat or soothe for 1-2 minutes (no picking up), then leave. The idea is that baby learns to self-soothe while knowing you’ll return.
Timeline: 3-7 nights for most families. Hard part: Night 2 is often worse than Night 1. Many parents give up here. Push through.
Extinction (Cry It Out)
The most controversial. You do the bedtime routine, put baby down awake, say goodnight, and don’t go back in until morning (or a set time).
I’m not going to pretend this is easy. It isn’t. Night 1 can involve hours of crying. But for some babies, it works fast—often 2-4 nights.
The 2012 Pediatrics study that followed extinction-trained babies to age 6 found no differences in emotional health, behavior, or attachment compared to controls. It’s not harmful. But it’s also not necessary if you can’t tolerate it.
Not recommended before 6 months or for babies with medical conditions.
Pick Up/Put Down
Every time baby cries, you pick them up, calm them, and put them back down awake. Repeat until they fall asleep.
Some parents love this. Some babies take 20+ pick-ups the first few nights. It’s gentle but exhausting.
Timeline: 1-2 weeks. Works best for: Parents who genuinely can’t handle hearing their baby cry, babies under 6 months.
Chair Method
Put a chair next to the crib. Sit in it until baby falls asleep. Every 2-3 nights, move the chair further away until you’re outside the door.
This is gradual and less stressful for parents. It also takes 2-3 weeks and requires you to sit in a dark room for potentially hours each night. Bring a book.
Works best for: Babies with separation anxiety, parents who want a slow approach.
Fading
Gradually reduce whatever you’re doing to help baby sleep. If you rock for 15 minutes, rock for 12. Then 10. Then 7. Then just patting. Then just a hand on their back. Then sitting nearby. Then nothing.
This is the gentlest approach but also the slowest—often 3-4 weeks or more. The advantage: almost no crying. The disadvantage: you need patience.
Bedtime Routine Focus
No crying protocol at all. You focus entirely on sleep hygiene: consistent bedtime, dark room, white noise, predictable routine (bath, book, feed, bed). You respond whenever baby cries. Over time, the routine itself teaches sleep.
This works for some families and doesn’t for others. It’s the least structured approach, which can be freeing or frustrating depending on your personality.
Quick comparison
| Method | How long | Crying level | Best if you… |
|---|---|---|---|
| Ferber | 3-7 nights | Moderate | Want structure but struggle with long crying |
| Extinction | 2-4 nights | Higher | Can tolerate crying and want fastest results |
| Pick Up/Put Down | 1-2 weeks | Lower | Need to comfort baby but want independence |
| Chair | 2-3 weeks | Lower | Want gradual change |
| Fading | 3-4+ weeks | Lowest | Have patience and want gentlest option |
| Routine focus | Varies | Lowest | Prefer no “protocol” at all |
What actually matters
More than the specific method, success depends on a few things.
Consistency. This is everything. If you do Ferber for two nights, then pick baby up on night 3 because you can’t take it, you’ve taught them that crying long enough gets results. Pick a method and commit to at least a week.
Timing. An overtired baby has elevated cortisol and adrenaline. They fall asleep harder, not easier. Watch for sleep cues (yawning, rubbing eyes, looking away) and start the routine before they hit overtiredness.
Bedtime routine. Same activities, same order, every night. This isn’t optional. It’s how babies learn that sleep is coming. A 20-30 minute routine works well.
Environment. Dark room (blackout curtains), white noise (blocks household sounds), cool temperature (68-72°F). These matter more than you’d think.
All caregivers on board. If you’re doing Ferber but your partner or mother-in-law picks baby up when they cry, it won’t work. Discuss and agree on the plan before starting.
Common mistakes
Starting too early. Before 4 months, most babies aren’t developmentally ready. You’ll both be frustrated.
Changing methods too fast. Night 3-4 often has an “extinction burst”—more crying than before. This is normal. It means the method is working. Don’t switch methods now.
Inconsistency between bedtime and night wakings. If you sleep train at 7pm but rock to sleep at 2am, baby gets mixed messages. Be consistent, at least for the first stretch of the night.
Skipping the wind-down. Going from active play to crib doesn’t work. Babies need transition time.
When to get help
Talk to your pediatrician if:
- Baby snores, gasps, or stops breathing during sleep
- Sleep training isn’t working after 2 weeks of consistent effort
- You suspect reflux, ear infections, or other medical issues
- Your mental health is suffering
If exhaustion is affecting your emotional wellbeing, read our guide on postpartum mental health to understand what’s normal and when to seek support.
For sleep-specific help, the Association of Professional Sleep Consultants maintains a directory of certified consultants. Not cheap, but sometimes worth it.
FAQ
Is sleep training harmful?
The research says no. Multiple studies have found no differences in attachment, emotional development, or behavior between sleep-trained children and controls. A 2016 randomized controlled trial specifically tested this.
That said, sleep training isn’t mandatory either. Some families co-sleep, some respond to every cry, some parents are fine with night wakings for years. There’s no right answer here.
What if my baby cries for hours?
Some crying is normal—they’re protesting change. But use judgment. If your baby is hysterical, vomiting, or thrashing dangerously, go in. You may need a gentler method or a different timing. For more on understanding why babies cry and how to comfort them, see our guide on baby crying.
Can I breastfeed and sleep train?
Yes. The key is separating feeding from falling asleep. Nurse, then do the rest of the routine (diaper, book, song), then put baby down. Feed-to-sleep is a sleep association; nursing in general is not. For more on managing sleep while breastfeeding, see our guide to sleep for nursing moms.
What about naps?
You can sleep train for naps too, but start with bedtime first. The sleep drive is strongest at night, so it’s easier. Once bedtime is going well, apply the same method to naps.
What if baby gets sick?
Pause training. Comfort your baby. Resume when they’re well. Most babies go back to their previous progress within a few nights.
A note on expectations
Most babies will eventually sleep through the night whether you sleep train or not. This isn’t forever. Sleep training accelerates the process and gives parents some control over timing, but it’s not a moral requirement of good parenting.
If you try a method and it doesn’t feel right, try another. If nothing feels right, wait a few weeks and try again. The method you can actually implement is the one that works.
Sources:
- Gradisar M, et al. “Behavioral Infant Sleep Intervention.” Pediatrics. 2016;137(6)
- Hiscock H, et al. “Five-Year Follow-up of Harms and Benefits of Behavioral Infant Sleep Intervention.” Pediatrics. 2012;130(4):643-650
- Cleveland Clinic: When and How to Sleep Train Your Baby
- Sleep Foundation: Sleep Training for Babies