The crown-heel length in Caucasian infants born at 25-44 weeks gestation after last menstrual period were measured and the distribution determined.
weeks gestation |
mean-2 S.D. |
mean |
mean+2 S.D. |
25 |
31.6 |
34.6 |
37.6 |
26 |
32.6 |
35.6 |
38.6 |
27 |
33.5 |
36.6 |
39.7 |
28 |
34.5 |
37.6 |
40.7 |
29 |
35.6 |
38.8 |
42 |
30 |
36.6 |
39.9 |
43.2 |
31 |
37.8 |
41.1 |
44.4 |
32 |
39 |
42.4 |
45.8 |
33 |
40.3 |
43.7 |
47.1 |
34 |
41.5 |
45 |
48.5 |
35 |
42.7 |
46.2 |
49.7 |
36 |
43.8 |
47.4 |
51 |
37 |
45 |
48.6 |
52.2 |
38 |
46.1 |
49.8 |
53.5 |
39 |
47 |
50.7 |
54.4 |
40 |
47.4 |
51.2 |
55 |
41 |
47.9 |
51.7 |
55.5 |
42 |
47.7 |
51.5 |
55.3 |
43 |
47.5 |
51.3 |
55.1 |
44 |
47.2 |
51 |
54.8 |
Approximating Equations (JMP)
mean - 2SD =
= (0.0000164 * ((week gestation)^5)) - (0.002992 * ((week gestation)^4)) + (0.211049 * ((week gestation)^3)) - (7.237371 * ((week gestation)^2)) + (122.13336 * (week gestation)) -787.7081
mean =
= (0.0000139 * ((week gestation)^5)) - (0.002566 * ((week gestation)^4)) + (0.1822967 * ((week gestation)^3)) - (6.273504 * ((week gestation)^2)) + (106.14948 * (week gestation)) -680.1993
mean + 2SD =
= (0.0000114 * ((week gestation)^5)) - (0.00214 * ((week gestation)^4)) + (0.15354444 * ((week gestation)^3)) - (5.309638 * ((week gestation)^2)) + (90.165591 * (week gestation)) -572.6905
Specialty: Obstetrics & Gynecology, Pedatrics
ICD-10: ,