The Development of Standardized National Head Circumference Growth Charts for Jordanian Children Aged 0–5 Years: A Longitudinal and Cross-Sectional Study

<b>Background:</b> Head circumference (HC) is a key indicator of growth and brain development in children, used to identify abnormalities like microcephaly and macrocephaly. While WHO growth standards are widely adopted, they may not account for regional variations due to genetic, environmental, and socio-economic factors. This study aimed to develop and validate national HC growth charts for Jordanian children aged 0-5 years and compare them with WHO standards. <b>Method:</b> This study analyzed 628,456 HC measurements from 250,276 Jordanian children (51.6% boys, 48.4% girls) aged 0-1800 days, using data from the Hakeem program. Only healthy children were included. HC measurements followed international guidelines, and data were analyzed using the Lambda-Mu-Sigma (LMS) statistical method. Percentiles were calculated, and growth patterns were compared with WHO standards. <b>Results:</b> National HC-for-age growth charts were developed for the 3rd, 15th, 50th, 85th, and 97th percentiles. Median percentiles for Jordanian children aligned with WHO standards, but the 3rd percentile was lower, particularly for girls after 840 days. The 97th percentile diverged after 240 days, with larger HC measurements observed in Jordanian children. <b>Conclusions:</b> This study provides the first validated HC growth charts for Jordanian children, addressing the limitations of international standards in reflecting regional variations. These charts offer clinicians and public health professionals a precise tool for assessing and monitoring growth, promoting better health outcomes in Jordanian children.