Rustico Maria Angela, Lanna Mariano, Faiola Stefano, Casati Daniela, Spaccini Luigina, Righini Andrea, Parazzini Cecilia, Napolitano Marcello, Scelsa Barbara, Lista Gianluca, Corti Carla, Riccipetitoni Giovanna, Cetin Irene
Fetal Therapy Unit 'Umberto Nicolini',Vittore Buzzi Children's Hospital,Università di Milano,Milan,Italy.
Clinical Genetics Service,Vittore Buzzi Children's Hospital,Università di Milano,Milan,Italy.
Twin Res Hum Genet. 2018 Dec;21(6):546-555. doi: 10.1017/thg.2018.58. Epub 2018 Oct 30.
Monochorionic twins, resulting from a single fertilized egg giving rise to two separate embryos, are monozygotic and considered genetically identical. However, discordant phenotypes have been reported in monozygotic twins. We analyzed a retrospective cohort of 155 monochorionic pregnancies (312 twins) with major discordant structural anomalies coded by the ICD-10 system in order to describe the spectrum of anomalies, the management of the pregnancies, and the perinatal outcome. Treatment options included conservative management, selective feticide with bipolar cord coagulation, or complete termination. All survivors underwent at least 24 months of postnatal follow-up. Discordancy was complicated by twin-to-twin transfusion syndrome in eight pregnancies (5%) and by selective intrauterine growth restriction in 41 (26%). Major structural anomalies affected one system in 139 cases (90%) and multiple systems in 16 (10%). Median gestational age at diagnosis was 19.1 weeks (IQR 16.4-21.3). The most frequent single-system anomalies involved the nervous and circulatory systems. In total, 72 anomalous twins (46%) and 116 normal co-twins (74%) were delivered at a median gestational age of 34.6 weeks (IQR 31.0-36.3). Neonatal/infant death of the anomalous twin occurred in 22 cases (14%), with an overall survival rate of 32% (50/155). Surviving anomalous twins underwent major surgery in 22/50 cases (44%), four of whom (8%) now suffer from severe neurologic morbidity. This study shows that a wide spectrum of major discordant structural anomalies can be found in monochorionic pregnancies. The outcome for the anomalous twin is poor, while the survival rate for the normal co-twin was 71%, with a favorable overall prognosis.
单绒毛膜双胎由单个受精卵发育成两个独立的胚胎，属于单卵双胎，被认为基因相同。然而，单卵双胎中也有不一致表型的报道。我们分析了一个回顾性队列，其中包括155例单绒毛膜妊娠（312例双胎），这些妊娠有国际疾病分类第10版（ICD - 10）系统编码的主要不一致结构异常，目的是描述异常谱、妊娠管理及围产期结局。治疗选择包括保守治疗、双极脐带凝固选择性减胎术或完全终止妊娠。所有存活者均接受了至少24个月的产后随访。8例妊娠（5%）因双胎输血综合征使不一致情况复杂化，41例（26%）因选择性胎儿生长受限使不一致情况复杂化。139例（90%）主要结构异常累及一个系统，16例（10%）累及多个系统。诊断时的中位孕周为19.1周（四分位间距16.4 - 21.3周）。最常见的单系统异常累及神经和循环系统。共有72例异常双胎（46%）和116例正常同胞双胎（74%）在中位孕周34.6周（四分位间距31.0 - 36.3周）时分娩。异常双胎中有22例（14%）发生新生儿/婴儿死亡，总体存活率为32%（50/155）。存活的异常双胎中有22/50例（44%）接受了大手术，其中4例（8%）目前患有严重神经功能障碍。本研究表明，单绒毛膜妊娠中可发现广泛的主要不一致结构异常。异常双胎的结局较差，而正常同胞双胎的存活率为71%，总体预后良好。
