Establishing Growth Reference Charts for Head Circumference of the Pakistani Children, Using the Lambda-Mu-Sigma (LMS) Statistical Method

For growth monitoring of brain, head circumference (HdC) reference data are needed. Rapid increase in the HdC is usually seen within first few years of life which marks histological changes in the brain. However, in Pakistan, there is a dearth of research on the potential use of HdC measurements. We aimed to develop the age and gender specific smoothed HdC growth reference charts for the Pakistani children, aged 2 to 5 years. A representative cross-sectional sample of 1474 Pakistani children, aged 2 - 5 years, was studied. Age and gender specific smoothed HdC growth reference values and their charts were obtained using the lambda-mu-sigma (LMS) statistical method. The smoothed HdC percentiles (3rd, 5th, 10th, 25th, 50th, 75th, 90th, 95th and 97th) were calculated and their charts were drawn. The percentile values of HdC increased with age in both sexes. The boys had more increase in HdC percentiles than the girls had, except for the 95th and 97th percentiles. Comparison of 50th percentiles of HdC with those of the other countries demonstrated that the Pakistani children had substantially lower HdC percentiles than their counterparts in the other populations. The results showed that reference values for the HdC were smaller than the corresponding reference values provided by the World Health Organization. Therefore, it is suggested that each country should produce its own HdC growth charts because the use of the charts of other countries as standards may provide misleading information of the children population under study.