Byrne J, Warburton D, Kline J, Blanc W, Stein Z
Teratology. 1985 Oct;32(2):297-315. doi: 10.1002/tera.1420320218.
The morphologic features of a consecutive series of 3,472 singleton spontaneous abortions are described. Of the total, 21% consisted of well-formed fetuses (over 30 mm long), 27.9% had no identifiable fetal tissues, 34.2% consisted of fetal membranes only, and the remainder, 16.8%, consisted of a variety of embryonic types. The rate of focal malformations among embryos over 10 mm in length and among fetuses was 16.4%. The overall rate of chromosome anomalies in the 1,356 karyotyped specimens was 39.8%. The vast majority, 94%, occurred in embryos less than 30 mm, and in specimens whose development had not proceeded beyond differentiation of fetal membranes. The rate of chromosome anomalies among nonmalformed fetuses (greater than 30 mm) was only 1.7%. However, the presence of limited embryonic development was not a good predictor of the presence of a chromosome anomaly. Slightly over half (56%) of all specimens less than 30 mm long had chromosome anomalies; for individual classes of such specimens the rate ranged from 45% to 81%. The morphologic category with the highest rate of karyotypic anomalies had an excess of monosomy X abortuses. A gradient of developmental level could be associated with the degree of intrauterine mortality of each chromosome anomaly; i.e., conceptuses with karyotypes that occur at term had a greater degree of embryonic development than karyotypes that are never seen among term births. Thus, trisomies 13, 18, and 21 were more often associated with fetuses, and less often with tissue fragments than other trisomies. Focal malformations were multiple and severe in abortuses with triploidy, trisomies 13 and 18, and monosomy X and mild in trisomy 21. With the exception of monosomy X the malformations were similar to, and not more severe than those reported from, term births with the same anomaly. The high rate of intrauterine mortality in conceptuses with chromosome anomalies could be ascribed to their failure to develop past the embryonic stages. However, the presence of an equally large fraction of chromosomally normal abortions with the same degree of rudimentary development suggests the existence of early and profound developmental problems that are not associated with anomalies of the chromosome complement.
本文描述了连续收集的3472例单胎自然流产的形态学特征。其中，21%为发育良好的胎儿（长度超过30毫米），27.9%未发现可识别的胎儿组织，34.2%仅为胎膜组织，其余16.8%为各种胚胎类型。长度超过10毫米的胚胎和胎儿中，局灶性畸形的发生率为16.4%。1356例进行核型分析的标本中，染色体异常的总体发生率为39.8%。绝大多数（94%）发生在长度小于30毫米的胚胎以及发育未超过胎膜分化阶段的标本中。非畸形胎儿（大于30毫米）的染色体异常发生率仅为1.7%。然而，胚胎发育受限并非染色体异常的良好预测指标。所有长度小于30毫米的标本中，略超过一半（56%）存在染色体异常；此类标本的各个类别发生率在45%至81%之间。核型异常发生率最高的形态学类别中，X单体性流产过多。发育水平的梯度可能与每种染色体异常的宫内死亡率相关；即，足月出现的核型的孕体比足月分娩中从未见过的核型具有更高程度的胚胎发育。因此，与其他三体相比，13、18和21三体更多与胎儿相关，而与组织碎片相关较少。三倍体、13和18三体以及X单体性流产的局灶性畸形多且严重，21三体则较轻。除X单体性外，这些畸形与具有相同异常的足月分娩中报告的畸形相似，且并不更严重。染色体异常的孕体宫内死亡率高可能归因于它们未能发育至胚胎阶段之后。然而，同样有很大一部分发育程度相同但染色体正常的流产表明存在与染色体组异常无关的早期且严重的发育问题。
