RESUMO
Background: Sequential embryo transfer has been recognized as a strategy to increase pregnancy rates in women undergoing in vitro fertilization and embryo transfer (IVF-ET). However, its impact on assisted reproductive outcomes remains to be substantiated by robust evidence. This systematic review aims to summarize and analyze the available evidence to investigate the effect of sequential embryo transfer on assisted reproductive outcomes. Methods: A comprehensive literature search was executed across the Pubmed, Cochrane Library, Web of Science, and Scopus databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data were aggregated utilizing a random effects model, and the resultant outcomes were articulated as odds ratios (ORs) along with their 95% confidence intervals (CIs). Results: The pooled results revealed a statistically significant enhancement in reproductive outcomes for infertile patients undergoing sequential embryo transfer as evidenced by elevated rates of chemical pregnancy (OR = 1.67, 95% CI = 1.23-2.27), clinical pregnancy (OR = 1.78, 95% CI = 1.43-2.21), and ongoing pregnancy (OR = 1.54, 95% CI = 1.03-2.31). Compared with cleavage-stage embryo transfer, sequential transfer yielded superior outcomes in terms of chemical pregnancy rate (OR = 2.08, 95% CI = 1.35-3.19) and clinical pregnancy rate (OR = 1.78, 95% CI = 1.37-2.31). Furthermore, among the repeated implantation failure (RIF) cohort, sequential embryo transfer surpassed blastocyst-stage transfer, delivering a heightened chemical pregnancy rate (OR = 1.66, 95% CI = 1.19-2.53) and clinical pregnancy rate (OR = 1.65, 95% CI = 1.19-2.27). Conclusion: Our meta-analysis indicates that sequential transfer may enhance clinical pregnancy rate in a small subgroup of well-selected women. While promising, further evidence from prospective studies is needed.
RESUMO
Schizothorax prenanti is a cold-water fish species with great economic importance in aquaculture in Western China, and the underlying mechanisms of muscle development and growth in S. prenanti remain to be elucidated. In this study, deep RNA sequencing was performed to provide an in-depth view of the transcriptome of skeletal muscle of S. prenanti with the specific objective to identify expressed genes in the skeletal muscle of S. prenanti at 30â¯days post-hatching (S01), 1â¯year (S02), and 3â¯years (S03). De novo assembly of high-quality reads generated 132,784 transcripts with an average length of 1282â¯bp and 67,596 unigenes with an average length of 1559â¯bp. 2445 unigenes were differentially expressed with 1483 up-regulated and 962 down-regulated in the skeletal muscle of S. prenanti at S01 and S02 stages, and 1936 unigenes were significantly impacted at S02 and S03 stages with 1153 increased and 783 decreased. GO analysis showed that the differentially expressed genes are involved in various biological processes with dominance by cell & cell part, binding & catalytic activity, and cellular process & metabolic process. KEGG enrichment suggested that there are considerable differences in the physiological processes at different stages of muscle development and growth of S. prenanti. PPAR signaling pathway, cardiac muscle contraction, fatty acid metabolism, tight junction, and focal adhesion were the top pathways enriched in comparison between S01 and S02 stages. Whereas significant enrichment of the TCA cycle, fatty acid metabolism, fatty acid elongation in mitochondria, valine, leucine and isoleucine degradation, porphyrin and chlorophyll metabolism, and propanoate metabolism pathway was found in differentially expressed genes identified between S02 and S03 stages. This study provides not only an overall insight into the global gene expression landscape in the skeletal muscle of S. prenanti, but also candidate genes or markers that can be used for further investigations of the underlying mechanisms of skeletal muscle development and growth of S. prenanti.