Study On Embryo Dynamics In Patients With Recurrent Abortion After Assisted Reproduction

Objective:The relationship between the developmental dynamics parameters and pregnancy outcome of the transplanted embryos in patients with recurrent abortion after assisted reproduction was studied by time-lapse monitoring(TLM).The aim was to identify some specific embryonic kinetic parameters corresponding to adverse pregnancy outcomes,so as to optimize the embryo selection,avoid the abortion after embryo transfer as far as possible,and improve the live birth rate of this group embryo transfer.Methods: Retrospective analysis was performed on clinical data of eligible patients and their embryos undergoing in-vitro fertilization and embryo transfer(IVF-ET)at the fertility center between December 2017 and January 2020.Basic information of the patients was collected,such as age,height and weight,as well as some of their clinical data,including the initial dosage of ovulation drugs,the duration of medication,the total amount of medication used in the cycle,and the thickness of the endometrium before embryo transfer.In addition,TLM system is used to record the relevant data of early embryonic development,including the time parameters corresponding to different embryonic development stages,including the emergence and disappearance of PN and the zygote to divide fully into 2/3/4/5 cells(t2,t3,t4,t5)and the synchronization of the second cell division(2 cells divided into 4 cells)(s2,t4-t3),the second cell division cycle(cycle2,t3-t2,cc2),and the third cell division cycle(cycle3,c5-c4,cc3).In addition,there are some special events during embryonic development,such as direct division,reverse division,unequal division,polykaryosis,and chromosome examination results of aborted embryonic tissues of the study group.The morphological dynamics of this population of embryos with recurrent abortion after embryo transfer were analyzed by using these data.Results: In this study,a total of 50 patients with the history of repeated abortion after embryo transfer and chromosome examination of the aborted tissues were collected,and54 of the related embryo data were collected.Among them,a total of 25 patients in the group with normal chromosome examination of aborted embryos and 26 embryos were collected.There were 25 patients and 28 embryos in the chromosome abnormality group.In addition,clinical data were collected from 23 patients and 35 embryos in the live birth group with a history of repeated abortion after embryo transfer.(1)There were no statistically significant differences among the three groups in age,body mass index,initial dosage,duration,total dosage,endometrial thickness,and human chorionic gonadotropin(h CG)at the assay date after embryo transplantation.(2)Compared with the three groups of embryos,there was no statistical difference in the parameters of PN occurrence,PN disappearance,t2,t3,t4,t5,s2,cycle2 and cycle3.(3)There were 89 embryos in the three groups,among which 27 embryos had one or more abnormal division events.Compared with the three groups of embryos,those with abnormal embryo chromosome examination in the abortion group were more likely to directly divide in the early stage of embryo development.Conclusion: Embryo kinetic parameters,such as the occurrence and disappearance of PN,t2,t3,t4,t5,s2,cycle2 and cycle3,have no obvious correlation with the abnormality of embryo chromosomes and cannot predict the pregnancy outcome after implantation,but further studies are still needed.The phenomenon of direct division in early embryo development is related to the pregnancy outcome after implantation,so it can be used as a reference index for embryo selection in the face of repeated abortion of the patient group after transplantation,and the embryos with this special division event should be avoided and regarded as the preferred embryos.