ABSTRACT
Objective · To investigate whether the quality of embryos will result in biochemical pregnancy or arrest of embryo development in the freezing and thawing cycles of in-vitro fertiliazation-embryo transfer (IVF-ET). Methods · The clinical data of patients who accepted IVF-ET in Center of Reproductive Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine from January 2015 to June 2016 were retrospectively studied. The data includes 115 cycles of biochemical pregnancy, 64 cycles of arrest of early embryonic development and 871 cycles of ongoing pregnancy after frozen thawed embryo transfer. We compared the embryo score on the third day after embryo transfer (D3), the blastocyst development rate and the blastocyst grade in the three groups. Results · There were no significant differences in the period of infertility, the age of the patients and their spouses, the endometrial thickness, the estrogen and progestogen levels of the day of transplantation among the three groups (P > 0.05). The scores of most frozen thawed embryos on D3 were from 6 to 8, and the scores were not statistically significant among the three groups (P > 0.05). The proportion of transplanted blastocyst on D5 was higher than that on D6 in the three groups, but there was no significant difference among the three groups (P > 0.05). There was no significant difference in the proportion of inner cell mass of blastocysts which were scored as Grade A&B or Grade C among the three groups. Nevertheless, in the arrest of early embryonic development group, the proportion (52.2%) of the trophoblast of blastocysts which were cored as Grade C was significantly higher than the proportion (35%) in biochemical pregnancy group and the proportion (29.3%) in ongoing pregnancy group (P<0.05). Conclusion · The quality of embryos is not necessarily related to biochemical pregnancy, but the score of trophoblastic may be related to the arrest of early embryo growth.