Newborn rhythms are not schedules
Why feed-wake-sleep cycles work in week one and clocks do not.
A newborn does not have a circadian rhythm yet. Their melatonin system comes online around six to eight weeks, which is why a routine that worked at three weeks suddenly stops working at four. The most useful tool in the first months is the cycle, not the clock.
Most newborns can stay awake comfortably for forty-five to ninety minutes before they need to sleep again. Past that window, cortisol rises, and the baby who would have settled in two minutes now needs forty.
You are not aiming for a schedule. You are aiming for a sequence. Feed, brief alert time, soothe to sleep, repeat. That sequence tells the baby what comes next, even when the clock does not.
Try this week
- Watch for the second yawn, not the first cry. The first yawn is the cue.
- Time how long they were awake last cycle. Stay inside that window.
- Pick one sleep cue (a song, a smell, a phrase) and repeat it every nap.
Reference. Polly Moore, "The 90-Minute Baby Sleep Program"