News

16th June 2004

Babies in big families less likely to thrive

New research suggests that babies born into big families are more likely to struggle to thrive.

The findings come from a team at Bristol University who were part of the Children of the 90s project which followed 11,700 infants.

Failure to thrive is a medical term referring to infants whose weight gain is in the bottom 5 per cent. They do not grow as well as their peers. There is evidence that it is associated with a delay in proper development, and possibly problems in later life, including intellectual deficits.

The babies in the study were weighed at birth, then at 6-8 weeks old and again at 9 months. The researchers focussed on the 5 per cent who put on the least weight over that time.

It has long been assumed that babies born into a lower social status were more likely to fail to thrive. However, this study found the incidence of low growth was equal across all social classes and regardless of the parents' career or working status.

But the study did find a link between parents' height. Babies with short parents were 8 times more likely to fail to thrive in comparison to those with tall parents.

The risk of failure to thrive increased even with second and third babies. A firstborn baby had a 3.4 per cent risk, a second child increased to 4.6 per cent, whilst a third born child had a risk of 5.8 per cent which increased to 8.9 per cent for a fourth child.

Dr Peter Blair led the study and said more research was needed to find out why babies in large families suffered with slow growth. He said "While it may not be surprising that babies of short parents are more likely to grow slowly - we are the first study to establish this association.

"Growth standards for future measurement need updating and parental height must be part of this new calculation.

"The project is now investigating the growth and development of the children at seven and eight to assess the longer-term consequences of poor growth in the first year of life."

• Read our How does your baby grow? feature
• Discover how three mums resolved their baby's growth issue