Shi Xiaomei, Li Lin, Huang Xuan, Chen Baojiang, Zhou Yi, Fang Qun
Fetal Medicine Center, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
Fetal Diagn Ther. 2018;44(2):124-128. doi: 10.1159/000479685. Epub 2017 Sep 5.
To assess the clinical characteristics of fetal aneuploidy between dichorionic twins (DCT) and monochorionic twins (MCT) undergoing invasive prenatal diagnosis.
Twin fetuses undergoing invasive prenatal diagnosis were enrolled in this study. All twin fetuses were classified into 2 groups according to chorionicity. The rates of fetal aneuploidy in different groups were compared.
This study included 1,714 fetuses (857 sets of twin pairs); among them, 1,190 were DCT and 524 were MCT. Overall, the rate of aneuploidy was 4.7% (56/1,190) in DCT and 3.4% (18/524) in MCT. Sixty-four (86.5%, 64/74) fetal aneuploidies occurred in only one fetus of the twin pairs. In DCT, the most common aneuploidy was trisomy 21 (53.6%, 30/56), followed by trisomy 18 (21.4%, 12/56) and trisomy 13 (8.9%, 5/56), while in MCT, the most common aneuploidy was Turner syndrome (33.3%, 6/18), followed by trisomy 21 (27.7%, 5/18) and 47,XYY (11.0%, 2/18).
Aneuploidy mostly occurred in only one fetus in the twin pairs. The most common aneuploidy was trisomy 21 in DCT and Turner syndrome in MCT. Dual amniocentesis should be performed when discordant monozygotic twins are suspected.
评估接受侵入性产前诊断的双绒毛膜双胎（DCT）和单绒毛膜双胎（MCT）胎儿非整倍体的临床特征。
本研究纳入接受侵入性产前诊断的双胎胎儿。所有双胎胎儿根据绒毛膜性分为两组。比较不同组胎儿非整倍体的发生率。
本研究共纳入1714例胎儿（857对双胎）；其中，1190例为DCT，524例为MCT。总体而言，DCT中非整倍体发生率为4.7%（56/1190），MCT中为3.4%（18/524）。64例（86.5%，64/74）胎儿非整倍体仅发生在双胎中的一个胎儿。在DCT中，最常见的非整倍体是21三体（53.6%，30/56），其次是18三体（21.4%，12/56）和13三体（8.9%，5/56），而在MCT中，最常见的非整倍体是特纳综合征（33.3%，6/18），其次是21三体（27.7%，5/18）和47,XYY（11.0%，2/18）。
非整倍体大多仅发生在双胎中的一个胎儿。DCT中最常见的非整倍体是21三体，MCT中是特纳综合征。当怀疑单卵双胎不一致时应进行双羊膜腔穿刺术。
