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Sleep·8 min read·Reviewed: Mar 6, 2026

Baby Not Sleeping Through the Night? Causes and Solutions by Age

Why your baby wakes up at night and what to do about it. Age-specific causes, sleep regression timeline, and gentle solutions.

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ParAI Health Team

Reviewed against AAP, WHO & CDC guidelines

Baby Not Sleeping Through the Night? Causes and Solutions by Age
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Key Takeaways

  • Most babies don't consistently sleep through the night until 6–9 months
  • Night waking is developmentally normal — not a sign you're doing something wrong
  • Sleep regressions at 4, 8, and 12 months are temporary and usually last 2–4 weeks
  • Small changes to sleep environment and routine often make the biggest difference

If you're reading this at 3am with a wide-awake baby, you're not alone. Night waking is one of the most common challenges new parents face — and it's almost always temporary.

When Do Babies Sleep Through the Night?

"Sleeping through the night" medically means a 6-hour stretch — not 8pm to 7am. With that definition:

See also: Why Does My Baby Wake Up Screaming? Causes & Solutions and Baby Sweating While Sleeping: Causes & When to Worry.

  • 3 months — about 50% of babies can do a 5–6 hour stretch
  • 6 months — most babies are capable of 6–8 hours without feeding
  • 9–12 months — most babies sleep 10–12 hours with 0–1 wake-ups

Capable doesn't mean consistent

A baby who can sleep through the night won't always do so. Illness, teething, travel, and developmental leaps all cause temporary setbacks.

Why Your Baby Wakes Up: Causes by Age

AgeCommon CausesWhat to Do
0–3 monthsHunger (small stomach), startle reflexFeed on demand, swaddle
3–6 months4-month sleep regression, hunger, habitConsistent routine, gradual night weaning
6–9 monthsSeparation anxiety, teething, milestonesComfort briefly, pain relief for teething
9–12 monthsStanding/walking practice, 8-month regressionPractice new skills during day, consistent response

Sleep Regression Timeline

Sleep regressions are periods when a baby who was sleeping well suddenly starts waking more. They're caused by developmental leaps:

  • 4 months — the biggest one. Sleep cycles permanently mature. Lasts 2–6 weeks
  • 6 months — mild. Related to separation anxiety and solid food introduction
  • 8–10 months — crawling, pulling up, separation anxiety peak. Lasts 2–4 weeks
  • 12 months — walking, nap transition from 2 to 1. Lasts 1–3 weeks

The golden rule of regressions

Don't create new habits during a regression that you'll need to undo later. If you start co-sleeping or feeding to sleep during a regression, it may become the new normal.

Gentle Solutions That Work

  • Consistent bedtime routine — same 3–4 steps every night (bath, book, song, bed)
  • Put down drowsy but awake — helps baby learn to self-settle
  • Wait before responding — give 2–3 minutes before going in. Many babies resettle on their own
  • Gradual withdrawal — slowly reduce your presence at bedtime over 1–2 weeks
  • Dream feed — feed at 10–11pm before you go to bed to extend the first stretch
  • White noise — masks household sounds and mimics the womb

Creating the Ideal Sleep Environment

  • Dark room — blackout curtains make a significant difference
  • Cool temperature — 68–72°F (20–22°C) is ideal
  • White noise — continuous, not intermittent
  • Safe sleep surface — firm mattress, no loose bedding (AAP guidelines)
  • Consistent sleep location — same crib/bassinet for naps and nighttime

When to Talk to Your Pediatrician

  • Baby is over 6 months and waking every 1–2 hours consistently
  • Loud snoring or pauses in breathing during sleep
  • Baby seems in pain when waking
  • Extreme difficulty falling asleep (takes over 45 minutes consistently)
  • You're concerned about your own sleep deprivation and mental health

Struggling with Sleep? Try ParAI's AI Sleep Coach

ParAI's AI Sleep Coach creates a personalized sleep plan based on your baby's age, temperament, and patterns. Daily check-ins, progress tracking, and evidence-based guidance.

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This article is for informational purposes only and is not a substitute for professional medical advice. Always consult your pediatrician for specific questions about your child's health.