探讨妊娠11~13⁺⁶周双胎颈后透明层（NT）增厚、NT差异及头臀长（CRL）差异在筛查双胎胎儿不同严重程度心脏畸形中的临床价值。

回顾性分析在首都医科大学附属北京妇产医院（2012年1月至2016年12月）和石家庄市第四医院（2014年1月至2018年12月）建档并已知妊娠结局的双胎病例，筛选双胎之一或两胎儿发生心脏畸形的病例，按照心脏畸形严重程度分为轻度心脏畸形组和复杂心脏畸形组，将同时期分娩的正常双胎作为对照组。记录所有入组病例在妊娠11~13⁺⁶周的NT值、NT值≥第95百分位数和NT值≥第99百分位数的例数、NT差异≥20%和CRL差异≥10%的例数。采用χ²检验或Fisher's确切概率法进行组间对比分析，再应用Logistic回归分析筛选双胎心脏畸形发生的危险因素。

（1）双胎心脏畸形者共23例，其中轻度心脏畸形组14例，复杂心脏畸形组9例，正常对照组1906例。（2）与正常对照组相比，复杂心脏畸形组NT值≥第95百分位数和NT值≥第99百分位数的发生率、CRL差异≥10%的发生率明显增高，差异具有统计学意义（χ²=63.628、53.480、8.064，P<0.001、<0.001、=0.020），而NT差异≥20%的发生率差异无统计学意义（P>0.05）。轻度心脏畸形组与正常对照组相比各项指标差异均无统计学意义（P均>0.05）。轻度心脏畸形组与复杂心脏畸形组之间除NT值≥第95百分位数的发生率差异具有统计学意义（χ²=4.480，P=0.014），其他指标差异均无统计学意义（P均>0.05）。（3）多因素Logistic回归分析显示，NT值增厚（即NT值≥第95百分位数）是双胎复杂心脏畸形发生的独立危险因素（OR=31.571，95%CI：8.022~124.246，P<0.001），但CRL差异≥10%并不是双胎复杂心脏畸形发生的独立危险因素（P>0.05）。

妊娠11~13⁺⁶周超声发现一胎或两胎NT值增厚、两胎儿间CRL差异≥10%提示双胎发生复杂性心脏畸形的风险增加；NT增厚是双胎发生复杂性心脏畸形的危险因素。

To assess the clinical value of nuchal translucency (NT) thickening, NT discordance, and crown-rump length (CRL) discordance in screening twins with different degrees of congenital heart malformation at 11-13⁺⁶ weeks of pregnancy.

A retrospective analysis was performed on twin fetal cases collected from Beijing Obstetrics and Gynecology Hospital Capital Medical University/Beijing Maternal and Child Health Care Hospital (January 2012 to December 2016) and the Fourth Hospital of Shijiazhuang City (January 2014 to December 2018). Fetuses with cardiac malformation were screened out and divided into either a mild cardiac malformation group or a complex cardiac malformation group according to the degree of cardiac malformation, and normal twins delivered at the same time were used as controls. The NT value of all enrolled cases at 11-13⁺⁶ weeks of gestation was obtained, and the number of cases with NT value ≥ the 95th percentile, NT value ≥ the 99th percentile, NT discordance ≥ 20%, and CRL discordance ≥ 10% was recorded. The χ² test or Fisher's exact probability method was used for comparative analysis between groups, and Logistic regression analysis was used to screen the risk factors for cardiac malformations in twins.

There were 23 cases of twins with cardiac malformation, including 14 cases in the mild cardiac malformation group, 9 cases in the complex cardiac malformation group, and 1906 cases in the normal control group. Compared with the control group, the incidence of NT value ≥ the 95^th percentile, NT value ≥ the 99^th percentile, and CRL discordance ≥ 10% in the complex cardiac malformation group was significantly higher (χ²=63.628, 53.480, and 8.064; P<0.001, <0.001, and =0.020, respectively), while the incidence of NT discordance ≥ 20% was not statistically different between the complex cardiac malformation group and the control group. There was no statistically significant difference in various indicators between the mild cardiac malformation group and the control group. Except for the NT value ≥ the 95th percentage (χ²=4.480, P=0.014), there was no significant difference in other indicators between the mild cardiac malformation group and the complex cardiac malformation group. Multivariate Logistic regression analysis showed that increased NT (NT value ≥ the 95^th percentile) was an independent risk factor for the occurrence of complex cardiac malformations in twins (odds ratio=31.571, 95% confidence interval: 8.022-124.246, P<0.001), but CRL discordance ≥ 10% was not an independent risk factor for complex cardiac malformation in twins (P>0.05).

Ultrasound at 11-13⁺⁶ weeks of gestation reveals NT increase in one or two fetuses of the twins, and CRL discordance ≥ 10% indicates an increased risk of complex cardiac malformations in twins. Increased NT is a risk factor for complex heart malformations in twins.