Gentic Medical Center, Guangdong Women and Children Hospital, Guangzhou, China.
J Matern Fetal Neonatal Med. 2022 Aug;35(16):3152-3157. doi: 10.1080/14767058.2020.1814242. Epub 2020 Sep 9.
To compare prenatal and perinatal outcomes of twin pregnancies in which one twin the nuchal translucency (NT) was above the 95th percentile in dichorionic twins (DCT) and monochorionic twins (MCT).
In this retrospective study, 93 twin pregnancies (186 fetuses) in which one twin the NT was above the 95th percentile and the co-twin had normal NT were analyzed. Results of of G-banding and Chromosomal microarray (CMA), ultrasound findings and pregnancy outcomes were reviewed.
Totally, 57 pregnancies (114 fetuses) were DCT and 36 pregnancies (72 fetuses) were MCT. Karyotyping and CMA results shown that clinically significant chromosomal abnormalities were found in 16 fetuses, including 13 aneuploidies, 2 chromosomal mosaic and 1 pathological Copy number variations (CNVs) (14 were DCT and 2 were MCT). Overall, the incidence of fetal chromosomal abnormalities was 12.3% (14/114) in DCT and 2.8%(2/72) in MCT (χ = 3.932, = 0.047). Among the cases with normal prenatal diagnosis result, structural abnormalities were found in four fetuses (4.0%, 4/100) in DCT and two fetuses (2.9%, 2/70) in MCT ( 0.999). There were one intrauterine fetal demises (IUFD) and two miscarry in DCT. One IUFD, three subsequently developed Twin-to-Twin Transfusion Syndrome (TTTS) and four developed selective intrauterine growth restriction (sIUGR) in MCT. Totally, the overall fetal survival rate was 85.1% (97/114) in DCT and 80.6% (58/72) in MCT (χ = 0.653, = 0.419).
Compared to MCT, the incidence of chromosomal abnormalities in DCT discordant for one fetus with NT above the 95th percentile was higher. The risk of structural abnormalities and the rate of fetal survival for both MCT and DCT was similar.
比较颈项透明层（NT）增厚的双胎妊娠（DCT）和单绒毛膜双胎妊娠（MCT）中一胎的产前和围产儿结局。
在这项回顾性研究中，分析了 93 例双胎妊娠（186 例胎儿）中一胎 NT 超过第 95 百分位，而另一胎 NT 正常的情况。回顾了 G 显带和染色体微阵列（CMA）、超声检查结果和妊娠结局。
总共 57 例妊娠（114 例胎儿）为 DCT，36 例妊娠（72 例胎儿）为 MCT。核型分析和 CMA 结果显示，16 例胎儿存在临床意义的染色体异常，包括 13 例非整倍体、2 例染色体嵌合体和 1 例病理性拷贝数变异（CNVs）（14 例为 DCT，2 例为 MCT）。总的来说，DCT 胎儿染色体异常的发生率为 12.3%（14/114），MCT 为 2.8%（2/72）（χ=3.932，P=0.047）。在产前诊断正常的病例中，DCT 中有 4 例（4.0%，4/100）胎儿存在结构异常，MCT 中有 2 例（2.9%，2/70）胎儿存在结构异常（P=0.999）。DCT 中有 1 例宫内胎儿死亡（IUFD）和 2 例流产。MCT 中有 1 例 IUFD，随后 3 例发展为双胎输血综合征（TTTS），4 例发展为选择性宫内生长受限（sIUGR）。总的来说，DCT 胎儿存活率为 85.1%（97/114），MCT 为 80.6%（58/72）（χ=0.653，P=0.419）。
与 MCT 相比，NT 增厚的 DCT 中一胎的染色体异常发生率更高。MCT 和 DCT 的结构异常风险和胎儿存活率相似。
