Buekens P, Wilcox A
Department of Epidemiology and Social Medicine, School of Public Health, Free University of Brussels, Belgium.
Am J Obstet Gynecol. 1993 Mar;168(3 Pt 1):937-41. doi: 10.1016/s0002-9378(12)90849-2.
We propose an interpretation of the paradoxically better survival rate among low-birth-weight twins compared with low-birth-weight singletons.
We used data from Belgian birth and death certificates for 1983 and 1984. The data include 229,964 singletons, 2175 first twins, and 2153 second twins. Weight-specific perinatal mortality rates of twins and singletons were compared; the birth-weight distributions were adjusted to a single mean and SD.
After adjustment, mortality rates at every weight were higher for twins than for singletons.
The appearance of better survival among small twins compared with small singletons disappears after adjustment to relative birth-weight. There is a large risk resulting from twinning that falls on all twins, regardless of their weight.
我们提出了一种对低出生体重双胞胎与低出生体重单胎相比存活率反而更高这一矛盾现象的解释。
我们使用了1983年和1984年比利时出生和死亡证明的数据。数据包括229,964名单胎、2175对双胞胎中的第一个胎儿以及2153对双胞胎中的第二个胎儿。比较了双胞胎和单胎按体重划分的围产期死亡率；将出生体重分布调整为单一均值和标准差。
调整后，每个体重段双胞胎的死亡率均高于单胎。
在调整相对出生体重后，小双胞胎比小单胎存活率更高的现象消失了。双胞胎妊娠会给所有双胞胎带来巨大风险，无论其体重如何。
