人类胚泡倍性状态之间是否存在相关性,标准形态评估和延时动力学?
观察到相关性,在该整倍体人类胚泡中,具有高质量内细胞团(ICM)和滋养外胚层(TE)的百分比更高,更高的扩张等级和更短的开始囊胚的时间,膨胀和孵化,与非整倍体相比。
胚胎质量一直被认为是成功植入和妊娠的重要预测指标。然而,需要增加对胚泡阶段每个形态参数的相对影响的知识。最近,随着延时技术的引入,还可以评估形态动力学参数。然而,大量研究报告了相互矛盾的结果.
这是一项连续的病例系列研究。回顾性分析2012年9月至2014年4月在530个PGS周期中获得的1730个囊胚的形态,这些囊胚接受TE活检和阵列比较基因组杂交。在延时培养箱中培养总共928个胚泡,允许分析形态动力学参数。
女性平均年龄为36.8±4.24岁。四对hunderd54对夫妇参加了这项研究:其中384、64和6对单身夫妇,双或三PGS周期,分别。在标准形态学评估中,扩展等级,并对ICM和TE的质量进行了分析。观察到的形态动力学参数是第二极体挤出,两个原核的出现,原核褪色,开始两到八个细胞分裂,两单元和三单元(CC2)阶段与三单元和四单元(S2)阶段之间的时间,桑树形成时间,开始囊胚形成,全囊胚期,扩展和孵化时间。
在1730个活检囊胚中,603为整倍体,1127为非整倍体。我们观察到47.2%的整倍体和32.8%的非整倍体囊胚显示出高质量的ICM(P<0.001),17.1%的整倍体和28.5%的非整倍体囊胚显示质量差的ICM(P<0.001)。最高质量TE存在于46.5%的整倍体和31.1%的非整倍体囊胚中(P<0.001),而26.6%的整倍体和38.1%的非整倍体囊胚显示质量较差的TE(P<0.001)。关于扩展等级,81.1%的整倍体和72.4%的非整倍体囊胚完全扩大(5-6级;P<0.001)。从三细胞阶段到四细胞阶段的裂解时间,达到四细胞阶段,开始囊胚形成,达到完全囊胚期,囊胚扩增和孵化为2.6(95%置信区间(CI):1.7-3.5),40.0(95%CI:39.3-40.6),103.4(95%CI:102.2-104.6),110.2(95%CI:108.8-111.5),整倍体囊胚的118.7(95%CI:117.0-120.5)和133.2(95%CI:131.2-135.2)小时,和4.2(95%CI:3.6-4.8),41.1(95%CI:40.6-41.6),105.0(95%CI:104.0-106.0),112.8(95%CI:111.7-113.9),非整倍体囊胚的122.1(95%CI:120.7-123.4)和137.4(95%CI:135.7-139.1)小时(早期发育P<0.05,晚期发育P<0.0001),分别。对于其余的形态动力学参数,整倍体和非整倍体胚泡之间没有发现统计学上的显着差异。总共进行了407个胚胎移植(155个新鲜,252个冻融胚泡)。临床妊娠较高,与新鲜胚胎移植相比,冻融胚胎移植的着床率和活产率(分别为P=0.0104,0.0091和0.0148).冷冻保存和新鲜胚胎移植的流产率分别为16.1%和19.6%,分别。与非整倍体组相比,整倍体组的平均女性年龄较低(35.0±3.78比36.7±4.13岁,分别),我们发现女性年龄为每年10%时,非整倍体的可能性增加(比值比(OR)=1.1,95%CI:1.1-1.2,P<0.001)。
形态学评估的主要局限性在于它是一个静态系统,并且可以依赖于操作员。在这项研究中,8位胚胎学家进行了形态学评估.延时技术的主要限制是不可能旋转胚胎,这使得在卵裂球重叠或细胞质碎片增加的情况下很难观察它们。
尽管倍性状态与胚泡形态/发育动力学之间似乎存在关系,形态学和形态动力学参数的评估目前无法改进,并因此取代,PGS。我们对持续妊娠和流产率的研究结果表明,通过PGS或延时成像进行胚胎评估可能无法改善IVF结局。然而,延时监测可以与PGS结合使用,在一个队列中,胚泡分析或,当一个以上的整倍体胚泡可用时,选择哪一个应该被转移。
这项研究没有获得具体资助。没有任何作者有任何竞争的利益声明。
Are there correlations among human blastocyst ploidy status, standard morphology evaluation and time-lapse kinetics?
Correlations were observed, in that euploid human blastocysts showed a higher percentage with top quality inner cell mass (ICM) and trophectoderm (TE), higher expansion grades and shorter time to start of blastulation, expansion and hatching, compared to aneuploid ones.
Embryo quality has always been considered an important predictor of successful implantation and pregnancy. Nevertheless, knowledge of the relative impact of each morphological parameter at the blastocyst stage needs to be increased. Recently, with the introduction of time-lapse technology, morphokinetic parameters can also be evaluated. However, a large number of studies has reported conflicting outcomes.
This was a consecutive
case series study. The morphology of 1730 blastocysts obtained in 530 PGS cycles performed from September 2012 to April 2014 that underwent TE biopsy and array comparative genomic hybridization was analyzed retrospectively. A total of 928 blastocysts were cultured in a time-lapse incubator allowing morphokinetic parameters to be analyzed.
Mean female age was 36.8 ± 4.24 years. Four hunderd fifty-four couples were enrolled in the study: 384, 64 and 6 of them performed single, double or triple PGS cycles, respectively. In standard morphology evaluation, the expansion grade, and quality of the ICM and TE were analyzed. The morphokinetic parameters observed were second polar body extrusion, appearance of two pronuclei, pronuclear fading, onset of two- to eight-cell divisions, time between the two- and three-cell (cc2) and three- and four-cell (s2) stages, morulae formation time, starting blastulation, full blastocyst stage, expansion and hatching timing.
Of the 1730 biopsied blastocysts, 603 were euploid and 1127 aneuploid. We observed that 47.2% of euploid and 32.8% of aneuploid blastocysts showed top quality ICM (P < 0.001), and 17.1% of euploid and 28.5% of aneuploid blastocysts showed poor quality ICM (P < 0.001). Top quality TE was present in 46.5% of euploid and 31.1% of aneuploid blastocysts (P < 0.001), while 26.6% of euploid and 38.1% of aneuploid blastocysts showed poor quality TE (P < 0.001). Regarding expansion grade, 81.1% of euploid and 72.4% of aneuploid blastocysts were fully expanded (Grade 5-6; P < 0.001). The timing of cleavage from the three- to four-cell stage, of reaching four-cell stage, of starting blastulation, reaching full blastocyst stage, blastocyst expansion and hatching were 2.6 (95% confidence interval (CI): 1.7-3.5), 40.0 (95% CI: 39.3-40.6), 103.4 (95% CI: 102.2-104.6), 110.2 (95% CI: 108.8-111.5), 118.7 (95% CI: 117.0-120.5) and 133.2 (95% CI: 131.2-135.2) hours in euploid blastocysts, and 4.2 (95% CI: 3.6-4.8), 41.1 (95% CI: 40.6-41.6), 105.0 (95% CI: 104.0-106.0), 112.8 (95% CI: 111.7-113.9), 122.1 (95% CI: 120.7-123.4) and 137.4 (95% CI: 135.7-139.1) hours in aneuploid blastocysts (P < 0.05 for early and P < 0.0001 for later stages of development), respectively. No statistically significant differences were found between euploid and aneuploid blastocysts for the remaining morphokinetic parameters.A total of 407 embryo transfers were performed (155 fresh, 252 frozen-thawed blastocysts). Higher clinical pregnancy, implantation and live birth rates were obtained in frozen-thawed compared to fresh embryo transfers (P = 0.0104, 0.0091 and 0.0148, respectively). The miscarriage rate was 16.1% and 19.6% in cryopreserved and fresh embryo transfer, respectively. The mean female age was lower in the euploid compared to aneuploid groups (35.0 ± 3.78 versus 36.7 ± 4.13 years, respectively), We found an increasing probability for aneuploidy with female age of 10% per year (odds ratio (OR) = 1.1, 95% CI: 1.1-1.2, P < 0.001).
The main limitation of morphology assessment is that it is a static system and can be operator-dependent. In this study, eight embryologists performed morphology assessments. The main limitation of the time-lapse technology is that it is impossible to rotate the embryos making it very difficult to observe them in
case of blastomere overlapping or increased cytoplasmic fragmentation.
Although there seems to be a relationship between the ploidy status and blastocyst morphology/development dynamics, the evaluation of morphological and morphokinetic parameters cannot currently be improved upon, and therefore replace, PGS. Our results on ongoing pregnancy and miscarriage rates suggest that embryo evaluation by PGS or time-lapse imaging may not improve IVF outcome. However, time-lapse monitoring could be used in conjunction with PGS to choose, within a cohort, the blastocysts to analyze or, when more than one euploid blastocyst is available, to select which one should be transferred.
No specific funding was obtained for this study. None of the authors have any competing interests to declare.