Head circumference during infancy in a birth cohort of Sri Lankan children: are we using the correct chart?

INTRODUCTION Measuring head circumference and plotting it in centile charts is a routine practice in paediatrics. However if wrong charts are used, serious misinterpretations can ensue. OBJECTIVES This study was carried out to ascertain the appropriateness of charts used in Sri Lanka. Out of a birth cohort of 2215 children, 250 from each sex were invited for a follow up study. Head circumference was measured at 2, 4, 6, 9 and 12 months. Statistical characteristics of head circumference for each sex, at each age were calculated. RESULTS At the first follow up 244 boys and 241 girls were assessed. Out of this, 85% of boys and 86% of girls completed the follow up. CONCLUSIONS Head circumference of both sexes deviated significantly at all ages from the charts available in the Child Health Developmental Record (CHDR). Head circumference charts available in the CHDR are inappropriate for use in Sri Lankan children.