High-quality Cleavage Embryo versus Low-quality Blastocyst in Frozen-thawed Cycles: Comparison of Clinical Outcomes

Abstract

This study compared the clinical outcomes of the frozen-thawed cycles of high-quality cleavage embryos with low-quality blastocysts to provide a reference for the choice of frozen-thawed embryo transfer schemes and to improve clinical pregnancy rates. A retrospective analysis was performed on the clinical data of patients undergoing frozen-thawed embryo transfer at the Reproductive Medicine Center of Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology from 2016 to 2017. In total, 845 cases were divided into a high-quality cleavage embryo group (group A) and a low-quality blastocyst group (group B). Each group was further divided into subgroups based on the number of transplants. Group A was categorized into two subgroups comprising of 94 cases in subgroup A1 (1 high-quality 8-cell group) and 201 cases in subgroup A2 (2 high-quality 8-cell group). Group B was divided into four subgroups consisting of 73 cases in subgroup B1 (D53BC group), 65 cases in subgroup B2 (D54BC group), 110 cases in subgroup B3 (D63BC group), and 282 cases in subgroup B4 (D64BC group). The pregnancy outcomes and neonatal outcomes between the groups were compared. The clinical pregnancy rates (56.72% and 60.00%) and live birth rates (47.76% and 46.15%) in subgroups A2 and B2 showed no significant differences, but these rates were significantly higher in subgroups A2 and B2 than in the rest subgroups (P<0.05). The multiple birth rate (26.32%) in the subgroup A2 was significantly higher than that in the rest subgroups (P<0.05). There were no statistically significant differences in the abortion rates among all groups (P>0.05). In terms of neonatal outcomes, there were no statistically significant differences in the proportion of premature births, sex ratios, and birth defects among the low-weight and gigantic infants (P>0.05). Transplanting two high-quality cleavage embryos during the frozen-thawed embryo transfer cycles could significantly increase clinical pregnancy rates and live birth rates, but at the same time, it also increased the risks of multiple births and complications to mothers and infants. The D54BC subgroup had the most significant advantages among all groups (P<0.05). The rest low-quality blastocysts had clinical outcomes similar to the single high-quality cleavage embryo group.

Keywords

high-quality cleavage embryos / low-quality blastocysts / frozen-thawed transplantation / clinical outcomes

References

[1] MartinsWP, NastriCO, RienziL, et al.. Blastocyst vs cleavage-stage embryo transfer: systematic review and meta-analysis of reproductive outcomes. Ultrasound Obst Gyn, 2017, 49(5): 583-591

[2] GharenazNM, MovahedinM, MazaheriZ. Effects of re-vitrification of mouse morula and early blastocyst stages on apoptotic gene expression and developmental potential. Cell J, 2018, 19(4): 614-619

[3] GardnerDK, LaneM, StevensJ, et al.. Blastocyst score affects implantation and pregnancy outcome: towards a single blastocyst transfer. Fertil Steril, 2000, 73(6): 1155-1158

[4] RienziL, CimadomoD, DelgadoA, et al.. Time of morulation and trophectoderm quality are predictors of a live birth after euploid blastocyst transfer: a multicenter study. Fertil Steril, 2019, 112(6): 1080-1093

[5] DuT, WangY, FanY, et al.. Fertility and neonatal outcomes of embryos achieving blastulation on Day 7: are they of clinical value?. Hum Reprod, 2018, 33(6): 1038-1051

[6] FerreuxL, BourdonM, SallemA, et al.. Live birth rate following frozen-thawed blastocyst transfer is higher with blastocysts expanded on Day 5 than on Day 6. Hum Reprod, 2018, 33(3): 390-398

[7] DevineK, RichterKS, WidraEA, et al.. Vitrified blastocyst transfer cycles with the use of only vaginal progesterone replacement with Endometrin have inferior ongoing pregnancy rates: results from the planned interim analysis of a three-arm randomized controlled noninferiority trial. Fertil Steril, 2018, 109(2): 266-275

[8] TannusS, CohenY, SonWY, et al.. Cumulative live birth rate following elective single blastocyst transfer compared with double blastocyst transfer in women aged 40 years and over. Reprod Biomed Online, 2017, 35(6): S490-S490

[9] YangL, CaiS, ZhangS, et al.. Single embryo transfer by Day 3 time-lapse selection versus Day 5 conventional morphological selection: a randomized, open-label, non-inferiority trial. Hum Reprod, 2018, 33(5): 869-876

[10] RenXL, ZhangHW, LiuQ, et al.. Analysis of influencing factors of single blastocyst transplantation during resuscitation cycle. Acta Med Univ Sci Technol Huazhong (Chinese), 2011, 40(06): 742-745

[11] ThompsonSM, OnwubaliliN, BrownK, et al.. Blastocyst expansion score and trophectoderm morphology strongly predict successful clinical pregnancy and live birth following elective single embryo blastocyst transfer (eSET): a national study. J Assist Reprod Genet, 2013, 30(12): 1577-1581

[12] DuSR, LinYH, LinDL, et al.. Relationship between single blastocyst score and fertility outcome during the resuscitation cycle. China Maternal Child Health Care (Chinese), 2016, 31(10): 2144-2146

[13] DuQY, WangEY, HuangY, et al.. Blastocoele expansion degree predicts live birth after single blastocyst transfer for fresh and vitrified/warmed single blastocyst transfer cycles. Fertil Steril, 2016, 105(4): 910-919.e1

[14] AhlstromA, WestinC, WiklandM, et al.. Prediction of live birth in frozen-thawed single blastocyst transfer cycles by pre-freeze and post-thaw morphology. Hum Reprod, 2013, 28(5): 1199-1209

[15] LundinK. Association between blastocyst morphology and outcome of single-blastocyst transfer. Reprod Biomed Online, 2013, 27(4): 353-361

[16] SunkaraSK, SiozosA, BoltonVN, et al.. The influence of delayed blastocyst formation on the outcome of frozen-thawed blastocyst transfer: a systematic review and meta-analysis. Hum Reprod (Oxford, England), 2010, 25(8): 1906-1915

[17] GuoN, DengTR, HuaX, et al.. Discussion on the clinical application value of blastocysts with different development speed in the single blastocyst freezing and thawing cycle. Maternal Child Health Care China (Chinese), 2019, 34(08): 1811-1515

[18] WuLM, ZouWW, JiDM, et al.. Analysis of pregnancy outcomes after freeze-thaw transplantation of blastocysts with different development days. Chinese J Reprod Contracep (Chinese), 2017, 37(10): 779-785

[19] YanFY, LiXJ, LuQ, et al.. Correlation between in vitro fertilization and blastocyst culture and D_2D_3 embryo blastomere number and fragment rating. J Pract Clin Med (Chinese), 2014, 18(17): 70-72

[20] WeiYL, ZhuGJ, RenXL, et al.. Developmental Potential and Clinical Value of Embryos with Abnormal Cleavage Rate. Curr Med Sci, 2019, 39(1): 118-121