Determining the Z Scores of Children Covered by Mashhad University of Medical Sciences and Comparing it with the WHO and CDC Standards

Document Type : Original Article


1 Mashhad University of Medical Sciences, Mashhad, Iran

2 2. Department of Epidemiology, School of Health, Management, Social Determinants of Health Research Center, Mashhad University of Medical Sciences, Mashhad, Iran

3 Department of Epidemiology, Faculty of Health, Mashhad University of Medical Sciences, Mashhad, Iran

4 Faculty of Traditional Medicine, Mashhad University of Medical Sciences, Mashhad, Iran


Background: The World Health Organization has introduced two sets of child growth standards for growth assessment. These reference values may not be suitable for use in other populations. Therefore, this study aimed to determine specific Z scores in the population covered by Mashhad University of Medical Sciences in Iran.
Methods: This cross-sectional study was conducted on data obtained from the evaluation of height, weight, and head circumference of children aged from 0 to 18 months visiting the healthcare centers of Mashhad University of Medical Sciences from March 2018 to March 2021. A total data of 128,472 children were extracted from the Electronic Health Records (SinaEHR®) and included in the study. Finally, the collected data were analyzed using Minitab and SPSS software (version 16).  
Results: The L, M, and S parameters were used to calculate Z scores for weight, height, and head circumference. These Z scores were then compared to standard deviation values ​for each age from our study and international standards to determine any differences. Our study found that mean weight scores were 0.16 kg higher than the CDC standard and 0.34 kg higher than the WHO growth standard.  
Conclusion: The provision of this exclusive reference to children's growth indicators not only allows for a more accurate evaluation but also provides the possibility of comparison with other populations using their specific growth charts. It seems that one of the best plans is to compare growth charts with international populations and national growth charts, which due to the electronization of the entire processes of the health system, is more possible than ever.


  1. Touwslager RN, Gielen M, Derom C, Mulder AL, Gerver WJ, Zimmermann LJ, et al. Determinants of infant growth in four age windows: a twin study. J Pediatr. 2011;158(4):566-72.
  2. Healy MJ, Lockhart RD, Mackenzie JD, Tanner JM, Whitehouse RH. Aberdeen growth study. I. The prediction of adult body measurements from measurements taken each year from birth to 5 years. Arch Dis Child 1956;31(159):372–381.
  3. Tanner JM. Foetus into man: physical growth from conception to maturity. Harvard University Press; 1990.
  4. Ong KK, Ahmed ML, Emmett PM, Preece MA, Dunger DB. Association between postnatal catch-up growth and obesity in childhood: prospective cohort study. Bmj. 2000;320(7240):967-71.
  5. Adair LS. Size at birth predicts age at menarche. Pediatrics 2001; 107:E59.
  6. Lampl M, Johnson ML, Frongillo Jr EA. Mixed distribution analysis identifies saltation and stasis growth. Ann Hum Biol. 2001;28(4):403-11.
  7. Lampl M, Veldhuis JD, Johnson ML. Saltation and stasis: a model of human growth. Science. 1992;258(5083):801-3.
  8. Thalange NK, Foster PJ, Gill MS, Price DA, Clayton PE. Model of normal prepubertal growth. Arch Dis Child. 1996;75(5):427-31.
  9. Hamill PV, Drizd TA, Johnson CL, Reed RB, Roche AF, Moore WM. Physical growth: national center for health statistics percentiles. Am J Clin Nutr. 1979;32(3):607-29.
  10. Dibley MJ, Goldsby JB, Staehling NW, Trowbridge FL. Development of normalized curves for the international growth reference: historical and technical considerations. Am J Clin Nutr. 1987;46(5):736–48
  11. El Mouzan MI, Al Salloum AA, Alqurashi MM, Al Herbish AS, Al Omar A. The LMS and Z scale growth reference for Saudi school-age children and adolescents. Saudi J Gastroenterol. 2016;22(4):331-6.
  12. Madarina J. Adoption of the WHO child Growth Standards To classify Indonesian children under 2 years of age according To nutrition status: Stronger indication for nutritional intervention. Food Nutr Bull. 2009;30(3):254-9.
  13. Taghavi N, Ebrahimi H, Karimi A PM. Evaluation of height and weight of 7-11 year old children in Shahroud in the academic years of 2003-2005 and its comparison with the world standard. Med Sci. 2007;17(2):95–101.
  14. del Pino M, Fano V, Lejarraga H. Growth references for height, weight, and head circumference for Argentine children with achondroplasia. Eur J Pediatr. 2011;170(4):453-9.
  15. Brown S, McSharry P. Improving accuracy and usability of growth charts: case study in Rwanda. BMJ Open. 2016;6(1):e009046.
  16. Reddy VS, Jahagirdar R, Deshpande R. Growth Parameters of under 2-year-old Indian Children: A Comparison to WHO MGRS 2006 Charts. Indian J Endocrinol Metab. 2020;24(2):176-180.
  17. Ouyang F, Jiang F, Tao F, Xu S, Xia Y, Qiu X, Zhang J. Growth patterns from birth to 24 months in Chinese children: a birth cohorts study across China. BMC Pediatr. 2018;18(1):344.
  18. Asif M, Aslam M, Wyszyńska J, Altaf S. Establishing body mass index growth charts for Pakistani children and adolescents using the Lambda-Mu-Sigma (LMS) and quantile regression method. Minerva Pediatr. 2020.
  19. Bong Y, Shariff AA, Mohamed AM, Merican AF. Malaysian growth centiles for children under six years old. Ann Hum Biol. 2015;42(2):108-15.
  20. Namakin K, Sharifzadeh GR, Zardast M, Khoshmohabbat Z SM. Comparison of the WHO child growth standards with the NCHS for estimation of malnutrition in Birjand-Iran. Int J Prev Med. 2014;5(5):653–7.
  21. Natale V, Rajagopalan A. Worldwide variation in human growth and the World Health Organization growth standards: a systematic review. BMJ Open. 2014;4(1):e003735.
  22. Physical status: the use and interpretation of anthropometry. Report of a WHO Expert Committee. World Health Organ Tech Rep Ser. 1995;854:1-452.