TABLE C-5Mean Weights and Percentiles for Placentas (singletons, twins, and triplets)

Gestational age (weeks)90th Percentile Mean Placental Weight 10th Percentile Cases (n)
SingletonsTwinsTripletsSingletonsTwinsTripletsSingletonsTwinsTripletsSingletonsTwinsTriplets
192632121612
2027028521825316622633
21172286320143231284114176257322
22191310345157251319122191289652
23211343400172276361133210331723
24233382445189307406145232371935
252564264982083414561592574081956
262804755582273805091752844441446
27305528630248421564192314480984
283315846972704646212103455161675
2935764177229350967922937755311126
30384700849316554738249409591121710
31411758925340600797269441631141315
324388151,00036464485529047267424297
334648701,072387687911311503719302714
344919231,139411727965331531768325343
355169711,2004347641,017352558821445233
365421,0141,2534577981,065372582878366619
375661,0511,2974788271,10839160294032588
385891,0821,3304998501,1474096191,00762545
396111,10551986842663110338
406321,11853787944263919347
416511,1235538824566428712

SOURCES: Pediatric Pathology & Laboratory Medicine by Pinar H., C. J. Sung, C. E. Oyer and D. B. Singer. Copyright 1996 by Informa Clinical Medicine—Journals. Reproduced with permission of Informa Clinical Medicine—Journals via Copyright Clearance Center; Reprinted from Pinar H., M. Stephens, D. B. Singer, T. K. Boyd, S. M. Pflueger, D. L. Gang, D. J. Roberts and C. J. Sung. 2002. Triplet placentas: reference values for weights. Pediatric and Developmental Pathology 5(5): 495–498 with kind permission from Springer Science and Business Media.

From: C, Supplementary Information on Composition and Components of Gestational Weight Gain

Cover of Weight Gain During Pregnancy
Weight Gain During Pregnancy: Reexamining the Guidelines.
Institute of Medicine (US) and National Research Council (US) Committee to Reexamine IOM Pregnancy Weight Guidelines; Rasmussen KM, Yaktine AL, editors.
Washington (DC): National Academies Press (US); 2009.
Copyright © 2009, National Academy of Sciences.

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