摘要：Ob.ective: This study was undertaken to investigate the association among plurality (numb.r of fetuses per pregnancy), ab.uptio placenta, and perinatal mortality. Study design: A retrospective cohort study on 15,051,872 singletons, 413,619 twins, and 22,585 triplets delivered in the United States b.tween 1995 and 1998 was conducted. We compared the occurrence of perinatal death b.tween pregnancies complicated b. ab.uptio placenta and those without with the use of adjusted odds ratios. The generalized estimating equations framework was applied to adjust for intracluster correlations among multiples. Results: Placental ab.uption occurred among 93,968 singletons (6.2 per 1000), 5051 twin (12.2 per 1000), and 353 triplet (15.6 per 1000) gestations (P for trend < .0001). Placental ab.uption was associated with significant risk of mortality irrespective of the plurality sub.ype. Perinatal mortality was greatest among singletons (adjusted odds ratio 95% CI = 14.3 13.2-15.4 ), followed b. twins (4.4 3.9-4.9 ) and least among triplets (3.0 2.0-4.6 ) (P for trend < .0001). Conclusion: As plurality increases from 1 to 3, the risk of placental ab.uption rises, whereas the risk of ab.uptio-associated perinatal mortality declines.