Faltering growth

Most babies lose weight after birth and then start regaining it at around two weeks of age. However, faltering growth (or failure to thrive) is when a baby does not gain weight at the expected rate

A baby’s development – particularly their brain development – may be affected if their growth falters, which is why it’s vital that the problem is recognised as quickly as possible.

How it's recognised

Every baby’s weight should be regularly checked against growth charts or centiles. These charts compare the baby’s weight, length and head circumference with babies of the same age and sex. Faltering growth is diagnosed:

  • If a baby loses more than 10 per cent of its birthweight or fails to regain its birthweight by day 14
  • If a baby’s weight slips two centiles or if it is consistently low for two months.


There are many reasons for faltering growth, with feeding problems being the most common. A baby may not be taking in enough calories for their development if they:

  • Are not fed often enough
  • Have a problem feeding and don’t get enough milk during each feed
  • Fall asleep before they’ve had enough
  • Are having infant formula milk that has been prepared incorrectly (e.g. it is too dilute).

When weaning starts, infants may not get enough calories and nutrients, particularly if they have too much fibre in their diet, which can fill them up. Persistent reflux, vomiting and cows’ milk protein allergy can also lead to faltering growth, as can medical conditions where food is not absorbed properly (e.g. coeliac disease), which can cause poor weight gain in babies.

A baby’s development – particularly their brain development – may be affected if their growth falters


Faltering growth needs to be diagnosed by a GP or health visitor, who will recommend appropriate treatments or referral to a paediatric dietitian.

For breastfed babies, the mother may need to increase her calorie and nutrient intake and get help with her breastfeeding technique. For formula-fed babies, special milks may be prescribed. In all cases, growth will need to be monitored carefully to ensure it returns to normal as quickly as possible and also to prevent undesirable excess weight gain.

Formula milks

Infant formula milks for faltering growth are nutritionally complete, energy-dense formulas (e.g. SMA High Energy). They can be used for medically identified increased energy and nutrient requirements, such as faltering growth, disease-related malnutrition and malabsorption.

These specialist formula milks can be used as the sole source of nutrition in babies from birth, in older babies to complement weaning, or mixed with foods for babies up to 18 months. The formulas have a protein:energy ratio close to that recommended for catch-up growth and are gentle on immature kidneys.

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