Baby Sleep — Everything You Need to Know
The 4 Sleep Regressions Explained
Sleep regressions are temporary disruptions caused by developmental leaps. Understanding why they happen makes them easier to survive.
- 4-month regression — Permanent shift in sleep architecture. Baby now cycles like an adult (light-deep-REM) every 45 min. Lasts 2–6 weeks.
- 8–10 month regression — Driven by separation anxiety and massive motor development (crawling, pulling to stand). Lasts 3–6 weeks.
- 12-month regression — Tied to the transition from 2 naps to 1. Also coincides with walking and first words.
- 18-month regression — Language explosion + molars + independence drive. One of the hardest. Usually resolves in 4–6 weeks.
Safe Sleep Guidelines (AAP 2024)
- Always place baby on their back for every sleep until age 1
- Use a firm, flat surface — approved crib, bassinet, or play yard with a fitted sheet only
- No soft objects — no pillows, bumpers, positioners, loose blankets, or stuffed animals
- Room-share without bed-sharing for at least the first 6 months, ideally 12 months
- Keep sleep space smoke-free and avoid overheating — baby's room should be 68–72°F (20–22°C)
- Pacifier at nap and bedtime reduces SIDS risk by up to 90% — offer after breastfeeding is established
Frequently Asked Questions
When do babies start sleeping through the night?
Most babies are developmentally capable of sleeping 6–8 hours by 4–6 months, though many don't achieve this until 9–12 months. 'Sleeping through the night' is widely defined as 5–6 consecutive hours. By 12 months, 70–80% of babies sleep through most nights.
What is the 4-month sleep regression?
Around 3–4 months, babies permanently shift from newborn sleep cycles to adult-like sleep architecture with 4 stages. They now fully wake between 45-minute sleep cycles — just like adults — but haven't learned to link cycles independently. This causes frequent night wakings. It is permanent but manageable with consistent sleep associations.
How many naps should my baby take?
Newborns: 4–5 naps/day. 3–4 months: 3–4 naps. 6–8 months: 3 naps transitioning to 2. 9–15 months: 2 naps. 15–18 months: transition to 1 nap. 3 years+: most children drop napping entirely.
Is it safe to let my baby sleep on their stomach?
No — the AAP strongly recommends back sleeping for all sleeps until age 1. Once a baby can independently roll both ways (usually 4–6 months), you don't need to reposition them if they roll to their stomach during sleep.
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