Growth spurts are the reason a baby who slept through the night is suddenly feeding every two hours. They are predictable, short, and very normal.
The classic timetable
The best-known spurts cluster around 2–3 weeks, 6 weeks, 3 months, and 6 months. Around each one, babies often feed more, sleep worse, and cling more for a few days.
Why it feels so intense
During a spurt a baby's body asks for more fuel to build. Fussiness usually tracks the growth spurt itself and settles as suddenly as it started.
When not to blame a spurt
Spurts are short. If fussiness, feeding difficulty, or fever goes beyond a few days, or weight stops climbing across checkups, talk to your pediatrician.
See the spurt in the data
Log measurements before and after a fussy week in GrowChart and you will often see the percentile jump that explains the whole episode.
Try the free calculator
No sign-up needed — check a percentile or z-score in seconds, then save & track when you create a free account.
Open the calculator → Create a free account