Mastroiacovo P, Castilla E E, Arpino C, Botting B, Cocchi G, Goujard J, Marinacci C, Merlob P, Métneki J, Mutchinick O, Ritvanen A, Rosano A
Birth Defects Unit, Catholic University, International Centre for Birth Defects, Rome, Italy.
Am J Med Genet. 1999 Mar 12;83(2):117-24. doi: 10.1002/(sici)1096-8628(19990312)83:2<117::aid-ajmg7>3.0.co;2-4.
Data provided by nine registries based in European and Latin America countries were analyzed to assess whether there is an excess of malformations in twins compared to singletons. Specific congenital malformations were coded according to the ninth revision of the International Classification of Diseases (ICD). Malformation rates and rate ratios (RR) for twins compared to singletons were calculated for each registry, and the homogeneity of the RRs was tested using the test of Breslow and Day. If departure from homogeneity in the different registries was not significant, registry-adjusted RRs with 95% confidence intervals were calculated. Overall, among 260,865 twins, 5,572 malformations were reported. A total of 101 different types of malformations or groups of defects was identified, and a homogeneous estimate of the RRs among registries was found for 91.1% of the malformations. Thirty-nine of the 92 malformations with homogeneous estimates of RRs were more common in twins than in singletons. For the remaining nine malformations, heterogeneous estimates of RRs were obtained. This study confirms the majority of already known associations and further identifies previously unreported malformations associated with twins. In conclusion, there is an excess of malformations in twins compared with singletons, and all anatomical sites are involved. The number of specific malformations associated with twins is higher than that previously reported in smaller studies.
对欧洲和拉丁美洲国家九个登记处提供的数据进行了分析，以评估双胞胎与单胎相比是否存在畸形过多的情况。特定先天性畸形根据《国际疾病分类》第九版（ICD）进行编码。计算每个登记处双胞胎与单胎的畸形率和率比（RR），并使用Breslow和Day检验来检验RR的同质性。如果不同登记处的同质性偏离不显著，则计算调整登记处后的RR及其95%置信区间。总体而言，在260,865例双胞胎中，报告了5,572例畸形。总共识别出101种不同类型的畸形或缺陷组，并且在91.1%的畸形中发现了登记处之间RR的同质估计。在RR同质估计的92种畸形中，有39种在双胞胎中比在单胎中更常见。对于其余9种畸形，获得了RR的异质估计。本研究证实了大多数已知的关联，并进一步识别出与双胞胎相关的先前未报告的畸形。总之，与单胎相比，双胞胎中畸形过多，并且所有解剖部位都有涉及。与双胞胎相关的特定畸形数量高于先前在较小研究中报告的数量。
