The Impact of Blastocyst Grade on Singleton Birthweight in Fresh Transplanted Cycles

Abstract Background: A retrospectively cohort study was performed to compare the birth weight of different blastocyst grades in fresh transplantation cycle and explore the related factors affecting the birth weight. Methods: The 1301 fresh cycles of single blastocyst transplantation and single live birth profile were analyzed,four groups were divided according to the grade of transplanted blastocyst. There are 170 cycles in group A with AA blastocyst grade, 312 cycles in group B with AB/BA blastocyst grade, 559 cycles in group C with BB/CA/AC blastocyst grade and 260 cycles in group D with BC/CB blastocyst grade. Comparison were made among four groups of birth weight, general conditions, fertilization rate, embryo rate, cleavage rate and D5,D6 blastocyst formation rate and other laboratory indicators. And then comparison were performed among the birth weight of different groups which were divided by the degree of blastocyst expansion, and the classification of inner cell mass(ICM) and the trophectoderm(TE). Results: The study shows that the birth weight of group A is significantly higher than that of the other three groups (P < 0.05). And the high quality embryo rate and blastocyst rate of group A are significantly higher than those of the other three groups (P < 0.05). What’s more, the clinical pregnancy rate, implantation rate and live birth rate of high grade blastocyst are higher, but there are no significant difference in abortion rate. The birth weight of the degree of blastocyst expansion in grade 3 and below is significantly lower than that of those with grade 3 and above (P < 0.05). The birth weight of grade A of ICM is significantly higher than that of grade B (P < 0.05). The birth weight of grade B of TE is significantly heavier than that of grade C (P < 0.05). Conclusions: Our results indicate that high grade blastocyst transplantation can achieve better pregnancy outcome. Different blastocyst grades affect birth weight, and low grade blastocyst transplantation is associated with a single birth weight loss.