vitababyIn short
Faltering growth (previously called failure to thrive) means a baby’s weight gain is slower than expected for their age, usually shown by their weight crossing downward through one or more centile spaces on the growth chart over time. It is a pattern that prompts a closer look, not a diagnosis on its own — most causes are to do with feeding or intake, and many babies catch up. In the UK it is assessed by a health visitor or GP, who looks at the whole picture: the trend, feeding, development, and general health.
Key takeaways
- Faltering growth describes slower-than-expected weight gain — typically downward centile crossing over time.
- It is a pattern that prompts assessment, not a diagnosis by itself.
- Most causes relate to feeding or intake, and many babies catch up.
- It is assessed by looking at the whole picture: trend, feeding, development, and health.
What the term means
Faltering growth is the term UK guidance (NICE) now uses for what used to be called failure to thrive. It describes a slower rate of weight gain than expected for a baby’s age, usually identified when weight crosses downward through centile lines on the chart over a period of time, rather than from a single low reading. A baby can be small and entirely healthy; what draws attention is a change in the pattern.
How centile crossing is read
Centile lines on the WHO/Red Book chart show where a baby sits relative to others of the same age and sex. Sitting steadily on a lower centile is usually fine. Crossing downward through one centile space can be normal in the early weeks; crossing two or more is more likely to prompt review. The early days after birth are a special case — most babies lose some weight then regain it, which is expected.
- A sustained downward trend matters more than any single weigh-in.
- Crossing two or more centile spaces usually prompts a closer look.
- Newborn weight loss and regain in the first weeks is normal.
Common causes
Most often, faltering growth comes down to a baby not taking in enough — through feeding difficulties, latch or supply issues, or simply needing more frequent feeds. Sometimes there is an underlying cause such as reflux, cow’s milk protein allergy, or an infection. Less commonly it relates to how the body uses energy. The assessment is about working out which of these, if any, applies.
What happens next
A health visitor or GP will usually review feeding, weigh and plot carefully, and look at your baby’s development and general health. Many babies simply need feeding support and closer monitoring, and catch up. If an underlying cause is suspected, they may suggest further checks or refer on. Keeping a clear record of feeds and weights makes this assessment quicker and more accurate.
VitaBaby charts the weight trend and logs feeds and intake over time, so the pattern behind a faltering-growth concern is easy to see and share with your health visitor or GP.
FAQ
Is faltering growth the same as failure to thrive?
Yes — “faltering growth” is the term UK guidance now uses for what was previously called failure to thrive. The newer term is less alarming and reflects that it describes a growth pattern rather than a fixed diagnosis.
Does crossing one centile line mean something is wrong?
Not necessarily. Crossing one centile space can be within normal variation, especially in the early weeks. Crossing two or more spaces, or a sustained downward trend, is more likely to prompt a review by your health visitor or GP.
Will my baby catch up?
Many babies with faltering growth catch up once any feeding issue or underlying cause is addressed. The outlook depends on the cause, which is why assessment by a health visitor or GP matters.
Sources
- Faltering growth (recognition and management) — National Institute for Health and Care Excellence (NICE)
- Baby weight and height — NHS
- Growth charts — Royal College of Paediatrics and Child Health