Placentas show a distribution in size and weight with increases seen with increasing gestational age.
|
week gestation |
placenta weight low |
mean placenta weight |
placenta weight high |
|
23 |
116.6 |
126 |
135.4 |
|
24 |
151.6 |
158.1 |
164.6 |
|
25 |
144.4 |
158.3 |
172.2 |
|
26 |
173.2 |
187.5 |
201.8 |
|
27 |
146.7 |
151.5 |
156.3 |
|
28 |
188.9 |
213.6 |
238.3 |
|
29 |
208 |
220.4 |
232.8 |
|
30 |
241.3 |
260.3 |
279.4 |
|
31 |
265 |
286.3 |
307.7 |
|
32 |
285.2 |
306.6 |
328 |
|
33 |
280.4 |
292.2 |
304.1 |
|
34 |
320.1 |
333 |
345.9 |
|
35 |
337.8 |
353.2 |
368.6 |
|
36 |
374.5 |
383.2 |
391.9 |
|
37 |
394.7 |
405.6 |
416.5 |
|
38 |
401.5 |
406.9 |
412.3 |
|
39 |
421.4 |
425.7 |
430 |
|
40 |
433.7 |
437.1 |
440.5 |
|
41 |
443.5 |
450.7 |
457.9 |
|
42 |
454.7 |
465 |
475.3 |
|
43 |
480.1 |
489 |
497.9 |
Initial line approximations:
placenta weight low =
= (18.98388 * (week gestation)) - 328.224
placenta weight high =
= (18.314558 * (week gestation)) - 282.6047
week gestation for low weight placentas =
= ((0.0000104 * ((placental weight) ^2)) + (0.0457037 * (placental weight)) + 18.303052
week gestation for mean weight placentas =
= ((0.0000264 * ((placental weight) ^2)) + (0.0365859 * (placental weight)) + 18.775538
week gestation for high weight placentas =
= ((0.0000436 * ((placental weight) ^2)) + (0.0260057 * (placental weight)) + 19.566584
Subsequent line approximations:
|
Line |
fetal weight = |
|
low, 23 to 34 weeks |
(0.6631 * ((weeks)^2)) - (19.81 * (weeks)) + 228.1 |
|
low, 34 to 43 weeks |
(-1.305 * ((weeks)^2)) + (115.9 * (weeks)) - 2111 |
|
high 23 to 34 weeks |
(0.2257 * ((weeks)^2)) + (6.56 * (weeks)) - 134 |
|
high, 34 to 43 weeks |
(-0.5576 * ((weeks)^2)) + (57.3 * (weeks)) - 953.2 |
Specialty: Obstetrics & Gynecology, Pedatrics
