Growth spurts are a frequently cited explanation for changes in infant behaviour — and the explanation is sometimes accurate. Understanding what actually happens during growth spurts (and when the term is being used loosely) helps parents respond appropriately to temporary disruptions in sleep and feeding.
Healthbooq provides developmental context for sleep behaviour throughout the first year.
Physical Growth Spurts
Physical growth spurts — periods of rapid height and weight gain — occur at somewhat predictable intervals in the first year (approximately 2–3 weeks, 6 weeks, 3 months, 6 months, and 9 months, though individual timing varies).
Sleep during physical growth spurts:- Increased sleep may occur. Growth hormone is released during slow-wave sleep, and the body may increase sleep depth and duration to support physical growth
- More frequent night feeding may occur. Increased caloric demand for growth can produce genuine hunger at intervals shorter than the child's usual overnight pattern
Duration: physical growth spurts typically last 2–5 days. A sudden return to more frequent feeding or more sleep that resolves within a week is consistent with a physical growth spurt.
Neurological/Developmental Leaps
Neurological growth spurts — periods of rapid cognitive, social, or motor development — produce a different pattern. During these periods:
- The infant may be more alert, wakeful, and difficult to settle
- Night wakings may increase
- The infant may seem clingy, unsettled, and wanting more contact
- Feeding may increase (particularly in breastfed infants, where feeding also serves a comfort function)
This pattern looks more like a sleep regression than a physical growth spurt and reflects the brain's increased activity during a developmental leap.
How to Respond
During physical growth spurts: respond to increased feeding demand; allow more sleep if the infant seeks it; don't force the usual schedule if hunger or tiredness signals are frequent.
During neurological leaps: maintain routines while offering more daytime contact and reassurance; avoid introducing new sleep associations to manage the temporary disruption.
Duration: both types of spurt are temporary — 2 days to 2 weeks. If disruption extends beyond 2–3 weeks, the cause is likely something other than a growth spurt.
Key Takeaways
Growth spurts — periods of accelerated physical or neurological development — are commonly associated with temporary changes in sleep and feeding. During physical growth spurts, infants may sleep more (growth hormone is released during sleep) and feed more frequently due to increased caloric demand. During cognitive or neurological leaps, the opposite pattern may occur — more wakeful, alert periods and less settled sleep. These are temporary patterns lasting a few days to 1–2 weeks.
