Sleep Regressions by Age: 4, 8, 12, 18 Months and 2 Years
A sleep regression is a short stretch — usually two to six weeks — when a baby or toddler who slept well starts waking often, fighting naps or resisting bedtime. Five arrive on schedule: 4, 8, 12 and 18 months, and again around age 2. Each one is temporary and tied to a leap in development.
Not medical advice: this page is general information for parents, not a diagnosis or treatment plan. If your baby is sick, feeding poorly, breathing oddly or you simply feel something is wrong, call your pediatrician. For emergencies, call your local emergency number.
The five regressions, at a glance
| Age | What changes | Typical length | First move |
|---|---|---|---|
| 4 months | 4-Month Sleep Regression | \1 | Hold wake windows at 1. |
| 8 months | 8-Month Sleep Regression | \1 | Practice standing-to-lowering in the daytime so the crib skill is learned when he is not tired. |
| 12 months | 12-Month Sleep Regression | \1 | Keep two naps while your baby still naps twice; dropping early tends to make early waking worse. |
| 18 months | 18-Month Sleep Regression | \1 | Keep the nap on the calendar — skipping it for a week guarantees an earlier, worse bedtime. |
| 2 years | 2-Year Sleep Regression | \1 | Keep the same bedtime to the minute for two weeks; predictability is the strongest signal you have. |
What works through any regression
- Hold the bedtime routine exactly — same three steps, same order, same voice.
- Protect the daytime nap; an skipped nap makes the night worse, not better.
- Respond the same way every wake (quiet presence, not a new game), so the phase cannot train a new habit.
- Keep wake windows inside the AAP- and NSF-aligned ranges for your child's age, then adjust one lever at a time.
- Get morning daylight and keep the room dark, so circadian timing holds while everything else wobbles.
What the guidelines say
The American Academy of Pediatrics (AAP) recommends a consistent bedtime routine and a separate, flat sleep surface for infants. The CDC puts total sleep at 12–16 hours a day for babies 4–12 months, 11–14 hours for ages 1–2 and 10–13 hours for ages 3–5, and the National Sleep Foundation (NSF) ranges match those numbers. Use them as ranges, not targets: total sleep differs from child to child.
Frequently asked questions
- What exactly is a sleep regression?
- A regression is a temporary stretch when an established sleeper starts waking more, fighting sleep or needing extra help settling. It is a change in patterns, not a permanent loss of skill, and it follows a developmental leap more often than illness.
- How long do sleep regressions last?
- Most run two to six weeks. Naps usually recover first, then night waking, then early wakes. If nothing improves after a month, treat it as a schedule problem: wake windows, nap length and bedtime are the three levers.
- How do I get through a regression without starting over?
- Hold the bedtime routine exactly, keep responses boring and consistent, protect the daytime nap, and pick one change at a time. Regression is the wrong moment for new rules, but the right moment for a steady hand.
- When should I talk to the pediatrician?
- Ask whenever waking comes with fever, breathing trouble, poor feeding or weight concerns, or when you have not slept longer than three hours a night for weeks. Parents' exhaustion counts as a reason to call, too.