The distribution in placental weights in Blacks and Whites were correlated with gestational age.
Measurements:
(1) weeks gestation is the number of weeks since the first day last normal menstrual period until delivery, rounded to a whole number
(2) placental weights are taken after removal of umbilical cord, membranes and blood clots
Data for Blacks
|
week gestation |
10th percentile |
25th percentile |
50th percentile |
75th percentile |
90th percentile |
|
28 |
188 grams |
213 grams |
240 grams |
270 grams |
293 grams |
|
29 |
208 |
232 |
261 |
291 |
318 |
|
30 |
230 |
255 |
290 |
321 |
355 |
|
31 |
247 |
275 |
310 |
350 |
385 |
|
32 |
268 |
296 |
335 |
378 |
415 |
|
33 |
280 |
313 |
356 |
398 |
440 |
|
34 |
291 |
330 |
375 |
419 |
463 |
|
35 |
298 |
343 |
390 |
438 |
483 |
|
36 |
308 |
356 |
408 |
455 |
500 |
|
37 |
320 |
368 |
418 |
468 |
513 |
|
38 |
333 |
380 |
431 |
480 |
523 |
|
39 |
348 |
390 |
442 |
490 |
530 |
|
40 |
363 |
400 |
453 |
498 |
535 |
10th percentile
= (0.1081002 * ((week gestation)^3)) - (11.43531 * ((week gestation)^2)) + (413.62816 * (week gestation)) - 4803.947
25th percentile
= (0.0067016 * ((week gestation)^3)) - (1.325425 * ((week gestation)^2)) + (82.329962 * (week gestation)) - 1202.135
50th percentile
= (-0.004079 * ((week gestation)^3)) - (0.381618 * ((week gestation)^2)) + (58.061522 * (week gestation)) - 999.2113
75th percentile
= (-0.025932 * ((week gestation)^3)) + (1.6136364 * ((week gestation)^2)) + (0.3436147 * (week gestation)) - 439.0512
90th percentile
= (-0.039918 * ((week gestation)^3)) + (2.6625874 * ((week gestation)^2)) - (20.8462 * (week gestation)) - 337.9613
Data for Whites
|
week gestation |
10th percentile |
25th percentile |
50th percentile |
75th percentile |
90th percentile |
|
28 |
202 grams |
225 grams |
254 grams |
278 grams |
310 grams |
|
29 |
228 |
252 |
278 |
302 |
328 |
|
30 |
250 |
272 |
302 |
325 |
353 |
|
31 |
265 |
290 |
323 |
350 |
382 |
|
32 |
278 |
308 |
345 |
380 |
415 |
|
33 |
290 |
325 |
365 |
407 |
Specialty: Obstetrics & Gynecology, Pedatrics |
