Sleep problems are the single most searched parenting topic in the UK. If you're reading this at 3am, you're not alone - and there are evidence-based approaches that help.
Why babies wake at night
Night waking is biologically normal for babies. Their sleep cycles are shorter than adults (around 45-50 minutes vs 90 minutes), and they naturally surface between cycles. Most babies don't consistently sleep through the night until somewhere between 6 and 12 months - and "sleeping through" is defined as a 5-hour stretch, not the 8 hours adults hope for.
Sleep regressions - what's actually happening
The 4-month "regression" isn't really a regression - it's a permanent change in sleep architecture. Your baby's sleep cycles are maturing from newborn patterns to adult-like patterns. This means more surface wakings, and they need to learn to link cycles independently. It typically lasts 2-4 weeks.
Other common disruptions happen around 8-10 months (separation anxiety and mobility), 12 months (transition from two naps to one), and 18 months (language explosion and independence).
What the evidence says about settling techniques
NHS guidance recommends a consistent bedtime routine: bath, book, bed - at the same time each night. The routine signals to your baby that sleep is coming, and consistency is more important than the specific activities you choose.
Gradual retreat (sitting beside the cot and slowly moving further away over days) has good evidence for reducing night waking without leaving your child to cry. Put your baby down drowsy but awake when possible, so they learn to fall asleep without being held or fed.
For toddlers who keep getting out of bed, calmly and silently return them each time. Don't engage in conversation or negotiation - the boring repetition is the point.
Safe sleep
For babies under 12 months, the Lullaby Trust and NHS recommend: always on their back, in a clear cot (no pillows, toys, or bumpers), in the same room as you for the first 6 months, at a comfortable temperature (16-20°C). Avoid falling asleep with your baby on a sofa or armchair - this carries a significant risk.