The head circumference 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 |
20.7 |
23.2 |
25.7 |
|
26 |
21.4 |
24 |
26.6 |
|
27 |
22.1 |
24.8 |
27.5 |
|
28 |
22.9 |
25.6 |
28.3 |
|
29 |
23.9 |
26.6 |
29.3 |
|
30 |
24.8 |
27.6 |
30.4 |
|
31 |
25.9 |
28.7 |
31.5 |
|
32 |
26.8 |
29.6 |
32.4 |
|
33 |
27.7 |
30.5 |
33.3 |
|
34 |
28.7 |
31.4 |
34.1 |
|
35 |
29.6 |
32.2 |
34.8 |
|
36 |
30.5 |
33 |
35.5 |
|
37 |
31.4 |
33.8 |
36.2 |
|
38 |
32 |
34.3 |
36.6 |
|
39 |
32.6 |
34.8 |
37 |
|
40 |
33 |
35.1 |
37.2 |
|
41 |
33.2 |
35.2 |
37.2 |
|
42 |
33.2 |
35.1 |
37 |
|
43 |
33.2 |
35 |
36.8 |
|
44 |
32.8 |
34.6 |
36.4 |
Approximating Equations (JMP)
mean - 2SD =
= (0.0000019 * ((week gestation)^5)) - (0.000353 * ((week gestation)^4)) + (0.0223161 * ((week gestation)^3)) - (0.606408 * ((week gestation)^2)) + (7.4149404 * (week gestation)) -15.2501
mean =
= (0.0000005 * ((week gestation)^5)) - (0.000073 * ((week gestation)^4)) + (0.0011661 * ((week gestation)^3)) + (0.1585645 * ((week gestation)^2)) - (5.832848 * (week gestation)) +75.363048
mean + 2SD =
= (-0.00000091 * ((week gestation)^5)) + (0.0002065 * ((week gestation)^4)) - (0.019984 * ((week gestation)^3)) + (0.9235368 * ((week gestation)^2)) - (19.08064 * (week gestation)) +165.9762
Specialty: Obstetrics & Gynecology, Pedatrics
ICD-10: ,
