ORIGINAL ARTICLE Neonatal length inaccuracies in clinical practice and related percentile discrepancies detected by a simple length-board Anna J Wood, 1 Camille H Raynes-Greenow, 2 Angela E Carberry 2,3 and Heather E Jeffery 2,3 1 Sydney Medical School and 2 School of Public Health, University of Sydney and 3 Newborn Care, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia Aim: The study aims to assess accuracy of standard practice measurement of neonatal length compared with a gold-standard length-board technique. Methods: Data were obtained from a population-based, cross-sectional study of 602 term babies at Royal Prince Alfred Hospital, Sydney, Australia, in 2010. Neonatal length was measured by standard clinical practice and by a length-board (gold standard) and measurements compared. Standard growth curve percentiles were used to plot length measurements. The Bland and Altman method was used to assess agreement, and acceptable levels of agreement were set at 1 cm and 0.5 cm. Results: The limits of agreement were between -3.06 cm (95% CI -3.08 to -3.04) and 2.67 cm (95% CI 2.65 to 2.69). Neonates whose standard-practice length fell within 0.5 cm of the gold standard totalled 41% (241 neonates), while 59% (342) were >0.5 cm. The change in length resulted in a change in the percentile range of 53% (309) on a standard growth curve percentile. When examining neonates whose length was plotted at the extremes of percentile regions, the positive predictive value results of the standard practice compared with the gold standard were poor, with positive predictive values of 37.5%, 57.1% and 31.3% for neonates who were measured as <3rd, <10th and 90th percentile, respectively. Conclusions: In current clinical practice, measures of neonatal length are often inaccurate, which has implications for potentially erroneous clinical care. Health-care providers should be educated on the importance of length and trained in how to measure length with the correct technique using a length-board. Key words: epidemiology; growth; length measurement; length-board; neonate; nutrition. What is already known on this topic 1 Neonatal length is a primary indicator of neonatal nutrition and forms the basis for important future treatment decisions. Few large studies exist that investigate the accuracy of neonatal length measurement in clinical practice. 2 Length and weight measurements at birth are plotted on stand- ard growth curves and compared with future growth measure- ments and important treatment decisions are made based on these measurements. 3 The emphasis is usually placed on weight when evaluating the nutritional state of neonates, while length is viewed as a second- ary factor that falters after weight has faltered. As a result length is often measured inaccurately or ignored in clinical practice. What this study adds 1 This study demonstrates inaccuracies in neonatal length measurement with resultant errors in plotted length for weight measurements. 2 Errors in length measurements may lead to inappropriate man- agement and failure to detect neonatal growth faltering, with adverse long-term outcomes. 3 Simple training in how to correctly use a length-board results in accurate length measurements with a near perfect intra-class correlation. Growth in the first years of life is an expression of health, nutritional status and well-being. 1 Length, as well as weight, is a sensitive and readily measurable indicator of malnutrition and other neonatal health problems. 2 Newborn measurement of length and weight reflects fetal nutrition and forms the basis on which future growth measurements are compared and impor- tant treatment decisions are made when they are plotted on standard growth curves. Furthermore, growth faltering and undernutrition are associated with long-term consequences including short adult height, cognitive impairments, morbidity and mortality. 3 Neonatal growth measurements include both weight and length. Yet when monitoring the nutritional state of neonates, emphasis is often placed on weight, while length is viewed as a secondary factor that falters after weight has faltered. 4 In 2006, Correspondence: Professor Heather E Jeffery, International Maternal and Child Health, Sydney School of Public Health, Edward Ford Building (A27), University of Sydney & Royal Prince Alfred Hospital, Newborn Care, Fisher Road, Sydney, NSW 2206, Australia. Fax: +61 2 9550 4375; email: heather.jeffery@sydney.edu.au Declaration of conflict of interest: The authors have no personal or financial relationships to disclose relevant to this article. Accepted for publication 6 February 2012. doi:10.1111/jpc.12119 Journal of Paediatrics and Child Health 49 (2013) 199–203 © 2013 The Authors Journal of Paediatrics and Child Health © 2013 Paediatrics and Child Health Division (Royal Australasian College of Physicians) 199