What is a normal rate of weight gain in infancy?
We have retrieved weights from the Child Health records of an annual cohort of 3418 full-term children, aged 18-30 months in order to define a lower limit of normality for weight gain for both clinical and research purposes. There was a strong tendency for children at the extremes of the distribution to move inwards towards the average: only 26% of those below the 3rd centile for weight at six weeks were still below it at one year. We describe a method based on conditional standards to correct for this "regression to the mean" and produce a measure of the discrepancy between a child's predicted and actual growth: the "thrive index". The value of the thrive index below which only a minority of children fell provided a lower threshold for normality. While most children below the 3rd centile for weight at 9-24 months of age also had subnormal weight gain, 41% of those with subnormal weight gain had not fallen below the 3rd centile.
Department of Child Health, University of Newcastle upon Tyne, UK.
C M
CM
Wright
J N
JN
Matthews
A
A
Waterston
A
A
Aynsley-Green
D002675:Child, Preschool; D004739:England; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012016:Reference Values; D015430:Weight Gain / Q000502:physiology*