My Baby Won't Sleep at Night: Real Causes and What to Do
Why your baby wakes at 2am — and the sleep window nobody told you about.
If your baby won't sleep at night, the first thing to know is it's not your fault — or theirs. Babies don't have a mature circadian rhythm until 3-4 months. Before that, their biological clock simply doesn't exist. What does exist is a "sleep window": the exact moment when the baby is ready to sleep. Miss it by 20 minutes and cortisol rises, leaving the baby over-stimulated. That's where the 2am nightmare begins.
How much a baby actually sleeps
0-1 month
14-17h
2-3 months
12-15h
4-6 months
12-16h
7-12 months
12-15h
5 signs your baby is ready to sleep
Rubs eyes or ears
Stares blankly or blinks slowly
Loses interest in toys or the breast
Whimpers with a soft, monotonous cry
Turns head to one side (rooting reflex)
The sleep window lasts 10-20 minutes. mi·ma calculates when it starts based on your baby's last feeding and last sleep. That's the SweetSpot.
What to do when the baby won't sleep at 2am
Total darkness: screens and light suppress melatonin in seconds
White noise at 65 dB (equivalent to the womb — activates the calming reflex)
Swaddle until 2 months: the Moro reflex wakes them on their own
Don't pick up immediately when crying — wait 60 seconds to see if they self-regulate
Check they're not hungry: calculate if more than 2.5h have passed since the last feeding
If your baby under 3 months sleeps more than 4-5 consecutive hours at night, wake them to feed. Their stomach is small and they need calories.
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The sleep window: act within 20 min of seeing sleep cues.
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In mi·ma
mi·ma tracks every feeding and nap, and alerts you when your baby's sleep window is about to open. No guessing.
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mi·ma is a support logbook for parents. This guide is informational and does not replace consultation with your pediatrician. For any concerns about your baby's health, consult a healthcare professional.
Sources
- · AAP Sleep Guidelines 2022
- · Harvey Karp — Happiest Baby on the Block
- · NIH — Infant Sleep Patterns
- · NSF — Sleep in Infants