The estimated standard deviation (SD) of body measurements at birth by gestational age (weeks). Five different sets of SD values are shown in each graph, i.e. based on the raw data adjusted for the exact gestational age in days without any distribution trimming and for four differently trimmed series, i.e. mean ± 0.5*SD (30.85% to 69.15%), mean ± 1.0*SD (15.87% to 84.13%), mean ± 1.5*SD (6.68% to 93.32%) and mean ± 2.0*SD (2.28% to 97.73%), respectively. Graphs of the left column are for boys while those of the right column are for girls. The upper panel shows the length at birth, the middle panel shows the weight at birth and the lower panel shows the head circumference at birth.