ABSTRACT
Objective:To explore the clinical outcomes of top-quality blastocysts transfer developed from cleavage embryos with different grading and determine whether the cleavage stage embryo morphology grading should be taken into consideration when transferring the embryo at the blastocyst stage.Methods:A number of 3 059 cycles were included with single top-quality blastocyst transfer dating from January 2017 to May 2021 in Henan Provincial People′s Hospital. According to the number of cleavage sphere and degree of fragmentation, all cleavage stage embryos were divided into three groups: top D3 embryo (8 cells, ≤5% fragments)-TB group, suboptimal D3 embryo (8 cells, 5%<fragments≤10%; 7 cells or 9 cells, ≤10%)-TB group, and normal D3 embryo-TB group. Univariate analysis, multivariate logistic regression analysis and threshold effect analysis were performed on the data.Results:The clinical pregnancy rates of top D3 embryo-TB group(1 326 cycles), suboptimal D3 embryo-TB group (830 cycles) and normal D3 embryo-TB group (903 cycles) were 69.53%, 70.12% and 66.67%, respectively ( P>0.05); and the early abortion rate were 10.74%, 12.54% and 12.62%, respectively ( P>0.05). After adjusting for confounders, logistic regression showed that no significant associations were found between cleavage stage embryo morphology grading and clinical pregnancy rate (suboptimal D3 embryo-TB group: OR=1.02, 95% CI: 0.76-1.38, P=0.879; normal D3 embryo-TB group: OR=0.84, 95% CI: 0.61-1.14, P=0.262) and early abortion rate (suboptimal D3 embryo-TB group: OR=1.18, 95% CI: 0.77-1.82, P=0.445; normal D3 embryo-TB group: OR=1.26, 95% CI: 0.81-1.98, P=0.309). The results of threshold effect analysis showed that when a single top-quality blastocysts was transferred, the effect of age on the clinical pregnancy rate showed a curve relationship, when the age was≥33 years old, the clinical pregnancy rate decreased significantly with age increased ( OR=0.89, 95% CI: 0.83-0.95, P=0.007); and there was no significant change in early abortion rate ( OR=1.01, 95% CI: 0.97-1.06, P=0.628). Conclusions:Cleavage stage embryo grading is not found to correlate with clinical outcomes in single top-quality blastcyst tranfer. Therefore, when considering blastocyst transfer, its morphology at blastocyst stage is more relevant. The effect of age on pregnancy outcomes of single blastocyst transfer should be considered.
ABSTRACT
Introdução: a biópsia embrionária tem como objetivo selecionar embriões geneticamente normais. Essa seleção ocorre por meio de testes genéticos pré-implantacionais. Espera-se, com isso, uma diminuição dos riscos de doenças genéticas e um aumento das taxas de implantação em fertilização in vitro. Objetivo: verificar, por meio de revisão bibliográfica, qual técnica de biópsia embrionária é considerada mais apropriada para feitura de testes genéticos pré-implantacionais. Método: pesquisa bibliográfica, na forma de revisão de publicações científicas, por meio das redes US National Library of Medicine (Pubmed), Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs), Google Acadêmico e Biblioteca Virtual em Saúde (BVS). Resultados e conclusão: existem três maneiras de efetuar a biópsia para reprodução humana assistida. A primeira consiste em retirar o primeiro e/ou o segundo corpúsculo polar estruído pelo oócito. Também se pode fazer a biópsia a partir de um blastômero do embrião em estágio de clivagem ou usar cinco a dez células do trofoectoderma de blastocisto. Normalmente as técnicas usadas para o diagnóstico são PCR, Fish, CGH array e SNP array, entre outras. Acredita-se que a biópsia de blastocistos é a melhor técnica para manter o potencial de implantação embrionária. Essa tendência se justifica por causa da maior quantidade de material genético disponível em fase avançada de desenvolvimento embrionário. Admite-se que nessa fase a incidência de mosaicismo seja menor em relação à biópsia de blastômeros, com consequente aumento na eficácia dos testes genéticos. Outra questão importante é que na biópsia de blastocistos as células são retiradas do trofoectoderma, enquanto que na biópsia em estágio de clivagem a remoção de um blastômero pode prejudicar o desenvolvimento embrionário.
Introduction: the embryo biopsy aims to select genetically normal embryos. This selection occurs through pre- implantation genetic testing. It is expected the reduction of risk ofgenetic disorders and increase implantation rates in IVF.Objective: to verify, through bibliographical revision, which embryo biopsy technique is considered more suitable for pre-implantation genetic diagnosis. Method: bibliographical research, in the form of literary review of scientific publications via networks, US National Library of Medicine (Pubmed), Latin-American Literature and Caribbean Health Sciences (Lilacs), Google Scholar and Virtual Health Library. Results and conclusion: there are three ways to perform the biopsy on assisted human reproduction.The first one consists in removing the 1st and/or 2nd polar body (if there wasfertilization). You can also perform the biopsy from the one blastomere of embryo cleavage stage or use 5-10 trophoectoderm cells blastocyst. Usually the techniques used for diagnosticpurpose are PCR, Fish, CGH array, SNP array and others. Nowadays it is believed that blastocyst biopsy is the best technique in order to maintain the embryonic implantation. This tendency is justified by the larger amount of genetic material available in an advancedstage of embryonic development. It is assumed that in this stage the incidence of mosaicism is reduced with the consequent increase in the effectiveness of genetic testing. Another important question is that the blastocyst biopsy cells are removed from the trophoectoderm while inbiopsy incleavage stage, the removal of one blastomere can impair embryonicdevelopment.