1 Forschungsinstitut für Kinderernährung (Research institute for child nutrition), Heinstück 11, D-4600 Dortmund 50, Federal Republic of Germany
To the Editor.
In their recent paper Roche and co-workers1 use the data of the Fels Longitudinal Study for the construction of reference charts for head circumference for children from birth to 18 years of age. However, we believe that there are problems with the method they used to fit the percentile curves to the data. The curves in figs 1 and 2 give the strong impression that growth of head circumference does not end at the age of 18 years for boys or girls.