单卵双胎发生机制及其危险因素的研究进展

Research progress on the pathogenetic mechanism and risk factors of monozygous twins

单卵双胎是双胎妊娠中的一种特殊类型。与双卵双胎相比,单卵双胎发生流产、胎儿畸形、胎死宫内、宫内生长受限及早产等风险均明显增加。单卵双胎的发生机制目前尚不明确,目前存在“两个模型”和“一个假说”理论,即“合子分裂模型”“胚胎膜融合模型”和“过度成熟配子”假说。辅助生殖技术与单卵双胎的发生密切相关。辅助生殖技术中的母体年龄、促排卵药物的应用、移植周期类型、胚胎培养时间、透明带操作、培养方式和培养液、遗传等均与单卵双胎的发生有关。本文对于单卵双胎的发生机制及危险因素新进展进行综述,以期为临床工作提供指导。

Monozygous twins(MZT)is a special type of twins.The risks of miscarriage,fetal malformation,intrauterine death,intrauterine growth restriction and preterm birth are significantly increased compared with dizygous twins(DZT).The mechanism of MZT has been still unclear.In recent years,studies have shown the existence of"two models"and"one hypothesis",namely"a fission event""a fusion event"and"overripe"gametes hypothesis.Assisted reproductive technology(ART)is closely related to the occurrence of MZT.The incidence of MZT after ART is related to maternal age,ovulation induction,type of embryo/blastocyst transfer cycle,days of embryo culture,zona pellucida micromanipulation,culture method and medium,heredity and other unknowm factors.This paper reviewed the new progress of the pathogenesis and risk factors of MZT,in order to provide guidance for clinical work.