Head circumference in Iranian infants

Background: Head circumference (HC) measurement is an important parameter in the diagnosis of neurological and developmental disorders as well as dysmorphic syndromes. Recognition of different disorders requires an understanding of the normal variation of the HC size, especially during infancy which is a period of rapid brain growth. Regarding the differences in the international and interracial standard charts of anthropometric indices, local and generational diversities, changes in the ethnic mix of the population and socioeconomic factors, periodic re-evaluations need to be done on the size of HC. This study aimed to represent a local HC standard for an Iranian infant population in comparison with the charts of the American National Center of Health Statistics (NCHS) approved by the World Health Organization (WHO). Methods: About 1003 neonates were randomly enrolled in this cross-sectional study. They were ageing from 3 days to 24 months and were apparently in normal condition. The HC size of these infants was measured and recorded. Tables and graphs were diagramed by Excel Microsoft Office 2007 software and two-tailed Student’s t-test was used for statistical analysis of data. Results: According to the findings of this study, the mean of the HC size in male infants was larger than the female ones. Based on a visual comparison, the curves followed a pattern similar to that of the NCHS’s. Overall, our subjects in both genders were found to have a smaller HC size at birth compared to the NCHS charts. However, infants of other ages had a larger HC size compared to that of the NCHS’s. Conclusion: With respect to the international and interracial differences in the HC size, it is recommended that local anthropometric indices be constructed and used clinically across the world. In addition, extensive and longitudinally designed studies are required in this regard.