School of Public Health, University of California, Berkeley, Berkeley, CA, USA.
Department of Health, Society, and Behavior, University of California, Irvine, Irvine, CA, USA.
Sci Adv. 2024 Sep 6;10(36):eado6691. doi: 10.1126/sciadv.ado6691.
Pregnancies ending before 26 weeks contribute 1% of births but 40% of infant deaths in the United States. The rate of these "periviable" births to non-Hispanic (NH) Black women exceeds four times that for NH whites. Small male periviable infants remain most likely to die. NH white periviable males weigh more than their NH Black counterparts. We argue that male infants born from twin gestations, in which one fetus died in utero (i.e., the vanishing twin syndrome), contribute to the disparity. We cannot directly test our argument because "vanishing" typically occurs before clinical recognition of pregnancy. We, however, describe and find associations that would emerge in vital statistics were our argument correct. Among male periviable singleton births from 288 monthly conception cohorts (January 1995 through December 2018), we found an average NH white advantage of 30 grams (759 grams versus 729 grams). Consistent with our argument, however, cohorts signaling relatively few survivors of the vanishing twin syndrome showed no disparity.
在美国，26 周前终止的妊娠占总分娩数的 1%，但却导致了 40%的婴儿死亡。非西班牙裔黑人女性的这种“极早产儿”出生率是西班牙裔白人的四倍以上。体型较小的男性极早产儿最有可能死亡。非西班牙裔白人极早产儿的体重比非西班牙裔黑人极早产儿重。我们认为，由双胞胎妊娠引起的男性婴儿死亡（即“消失的双胞胎综合征”）导致了这一差异。我们无法直接验证我们的论点，因为“消失”通常发生在妊娠临床诊断之前。然而，我们描述并发现了如果我们的论点正确，在生命统计中会出现的关联。在 1995 年 1 月至 2018 年 12 月的 288 个每月受孕队列中，我们发现男性极早产儿的平均非西班牙裔白人优势为 30 克（759 克对 729 克）。然而，与我们的论点一致的是，信号显示“消失的双胞胎综合征”幸存者相对较少的队列并没有显示出差异。
