Growth of Belgian and Norwegian children compared to the WHO growth standards: prevalence below -2 and above +2 SD and the effect of breastfeeding.

ABSTRACT

BACKGROUND: New national growth references have been published in Belgium and Norway. The WHO recommends universal use of their 2006 Child Growth Standards based on data from breastfed children. OBJECTIVE: To compare the growth of Belgian and Norwegian children with the WHO standards. PARTICIPANTS: 6985 children 0-5 years of age from Belgium and Norway. DESIGN: Proportion of children below -2 SD and above +2 SD of the WHO standards was calculated for length/height, weight, body mass index and head circumference. Average SD scores of exclusively breastfed children of non-smoking mothers were compared with national reference data and with the WHO standards. RESULTS: Generally, the number of Belgian and Norwegian children below -2 SD lines of the WHO standards was lower and above +2 SD higher than expected. The largest differences were for head circumference (0.97% Belgian and 0.18% Norwegian children below -2 SD, 6.55% Belgian and 6.40% Norwegian children above +2 SD) and the smallest for length/height (1.25% Belgian and 1.43% Norwegian children below -2 SD, 3.47% Belgian and 2.81% Norwegian children above +2 SD). The growth pattern of breastfed children of non-smoking mothers was in both countries more alike the local national growth references than the WHO standards. CONCLUSIONS: There are significant deviations in the proportion of children outside normal limits (±2 SD) of the WHO standards. This was true for all children, including those who were exclusively breastfed. Hence, adoption of the WHO growth charts could have consequences for clinical decision-making. These findings advocate the use of national references in Belgium and Norway, also for breastfed children.