Abstract：
Conjoined twins are estimated to occur in 1:50 000 pregnancies. Eighteen cases of pregnancies achieved by ART have been published of which three were achieved after single embryo transfer, allowing discussion of embryo characteristics. We report, to the best of our knowledge, the first case of parapagus conjoined twins after ART. Furthermore, this is the first report of conjoined twins with detailed morphokinetics of the earliest embryogenesis from zygote to expanded and hatched blastocyst stage. The case zygote had three refractile bodies, which were all allocated to one blastomere at first cleavage following an asynchronous pronuclei fading. Within 2 h, this blastomere cleaved to four and fragmented. The remaining blastomere cleaved symmetrically and regularly and a blastocyst (score: 4AB) was vitrified 120 h after IVF. Pregnancy was achieved following a frozen-thawed single blastocyst transfer. The etiopathogenetic mechanism of the origin of conjoined twins is unknown and several hypotheses exist. The morphokinetics in the present case and morphology of other reported cases will be discussed in this context.
摘要：
连体双胞胎估计发生在1:50000怀孕中。已经发表了18例通过ART获得的妊娠病例，其中3例是在单胚胎移植后获得的。允许讨论胚胎特征。我们报告,据我们所知,ART后第一例芦笋连体双胞胎。此外，这是关于连体双胞胎的首次报道，该双胞胎具有从受精卵到扩大和孵化囊胚期的最早胚胎发生的详细形态动力学。受精卵有三个折射体，在异步原核褪色后的第一次分裂时，全部分配给一个卵裂球。在2小时内，这个卵裂球分裂成四个，支离破碎。IVF后120小时，剩余的卵裂球对称且规则地切开，囊胚（评分：4AB）玻璃化。在冻融的单个胚泡移植后实现了妊娠。连体双胞胎起源的病因机制尚不清楚，存在一些假设。在这种情况下，将讨论当前情况下的形态动力学和其他报道病例的形态。
