Head circumference-for-age GIRLS Birth to 13 weeks (z-scores) Week
L
M
S
SD
0 1 2 3 4 5 6
1 1 1 1 1 1 1
33.8787 34.5529 35.2272 35.8430 36.3761 36.8472 37.2711
0.03496 0.03374 0.03251 0.03231 0.03215 0.03202 0.03191
7 8 9 10 11 12 13
1 1 1 1 1 1 1
37.6584 38.0167 38.3516 38.6673 38.9661 39.2501 39.5210
0.03182 0.03173 0.03166 0.03158 0.03152 0.03146 0.03140
Z-scores (head circumference in cm) -1 SD Median 1 SD
-3 SD
-2 SD
1.1844 1.1658 1.1452 1.1581 1.1695 1.1799 1.1893
30.3 31.1 31.8 32.4 32.9 33.3 33.7
31.5 32.2 32.9 33.5 34.0 34.5 34.9
32.7 33.4 34.1 34.7 35.2 35.7 36.1
33.9 34.6 35.2 35.8 36.4 36.8 37.3
1.1983 1.2063 1.2142 1.2211 1.2282 1.2348 1.2410
34.1 34.4 34.7 35.0 35.3 35.5 35.8
35.3 35.6 35.9 36.2 36.5 36.8 37.0
36.5 36.8 37.1 37.4 37.7 38.0 38.3
37.7 38.0 38.4 38.7 39.0 39.3 39.5
WHO Child Growth Standards
2 SD
3 SD
35.1 35.7 36.4 37.0 37.5 38.0 38.5
36.2 36.9 37.5 38.2 38.7 39.2 39.6
37.4 38.1 38.7 39.3 39.9 40.4 40.8
38.9 39.2 39.6 39.9 40.2 40.5 40.8
40.1 40.4 40.8 41.1 41.4 41.7 42.0
41.3 41.6 42.0 42.3 42.7 43.0 43.2