SUMMARYSeveral studies support of the use of testicular rather than ejaculated spermatozoa for intracytoplasmic sperm injection (ICSI) in couples with virtual azoospermia or cryptozoospermia, although this approach remains controversial. We sought to evaluate sperm retrieval outcomes with microdissection testicular sperm extraction (micro-TESE) in men with cryptozoospermia. We conducted a retrospective study of 24 consecutive micro-TESEs in men with cryptozoospermia. We also evaluated the outcomes of seven consecutive TESAs (testicular sperm aspiration) in cryptozoospermic men during the same time period (January 2007 and September 2014). Micro-TESE and TESA were performed on the day prior to ICSI. Final assessment of sperm recovery (reported on the day of ICSI) was recorded as (i) successful (available spermatozoa for ICSI) or (ii) unsuccessful (no spermatozoa for ICSI). The decision to perform a unilateral or bilateral micro-TESE was guided by the intra-operative evaluation of sperm recovery from the first testicle. A unilateral procedure was performed in 87.5% (21/24) and 57% (4/7) of the micro-TESE and TESA cohorts, respectively. Sperm recovery was successful in 96% (23/24) of the men who underwent micro-TESE and 43% (3/7) of the men who underwent TESA (p < 0.01). The ICSI pregnancy rates (per embryo transfer) in the micro-TESE and TESA groups were comparable [33% (6/18) and 50% (1/2), respectively]. The data indicate that micro-TESE is a highly successful sperm retrieval technique for men with cryptozoospermia and few of these men will require a bilateral procedure. Moreover, sperm retrieval rates are higher with micro-TESE than TESA in this group of men.
Epigenetics is a fundamental regulator underlying many biological functions, such as development and cell differentiation. Epigenetic modifications affect key chromatin regulation, including transcription and DNA repair, which are critical for normal embryo development. In this study, we profiled the expression of epigenetic modifiers and patterns of epigenetic changes in porcine embryos around the period of embryonic genome activation (EGA). We observed that Brahma-related gene 1 (BRG1) and Lysine demethylase 1A (KDM1A), which can alter the methylation status of lysine 4 in histone 3 (H3K4), localize to the nucleus at Day 3-4 of development. We then compared the abundance of epigenetic modifiers between early- and late-cleaving embryos, which were classified based on the time to the first cell cleavage, to investigate if their nuclear localization contributes to developmental competence. The mRNA abundance of BRG1, KDM1A, as well as other lysine demethylases (KDM1B, KDM5A, KDM5B, and KDM5C), were significantly higher in late- compared to early-cleaving embryos near the EGA period, although these difference disappeared at the blastocyst stage. The abundance of H3K4 mono- (H3K4me) and di-methylation (H3K4me2) during the EGA period was reduced in late-cleaving and less developmentally competent embryos. By contrast, BRG1, KDM1A, and H3K4me2 abundance was greater in embryos with more than eight cells at Day 3-4 of development compared to those with fewer than four cells. These findings suggest that altered epigenetic modifications of H3K4 around the EGA period may affect the developmental capacity of porcine embryos to reach the blastocyst stage. Mol. Reprod. Dev. 84: 19-29, 2017. © 2016 Wiley Periodicals, Inc.
Study question Can incorporation of novel markers of morphology with known temporal events successfully rank embryos to enable prediction of propensity for live birth? Summary answer Incorporation of variables for trophectoderm and morula grading demonstrably enhanced the model to rank embryos in order of potential for live birth. What is known already Models built using morphokinetic markers of development are widely used to rank embryos within a cohort. Such models include defined temporal parameters which are closely related to morphological grade. However, morphological grading by an embryologist is subjective and is not strongly correlated to outcome. Combining with defined kinetic events has been suggested to improve prediction of outcome. Study design, size, duration Data from 6228 known live birth outcome embryos from 8 UK clinics between 2011 – 2018 were investigated using an exploratory approach to identify novel markers of development. Participants/materials, setting, methods Five significant variables were defined, a derivative of time to start of blastulation; a derivative of trophectoderm grade; a kinetic variable utilising t3, t4, t5 and t8; an interval variable of tB-tSB and a variable based on novel morula classification. To maximise the output, a proxy value was derived for missing datapoints. The model was built using logistical regression and validated using fivefold cross validation with the data split as 80% training and 20% test. Main results and the role of chance An algorithm was developed including the five significant variables identified with an AUC of 0.685 demonstrating reliable prediction of live birth. Without morphological variables, the AUC was 0.674 demonstrating the improvement in the prediction value by including the derivative of the trophectoderm and morula grade. This resulted in ten classes of algorithm scores, 1–10, giving a live birth rate from 2% to 46%, irrespective of patient variables, for chance of live birth. Limitations, reasons for caution Successful application of the algorithm is reliant on stringent quality assurance for maintenance of accurate annotation and grading, and may not be transferable between laboratories with different SOPs. Wider implications of the findings: The addition of a trophectoderm and morula grade in combination with morphokinetic parameters, increases the predictive value of the algorithm in relation to live birth outcome. Using proxy values allows maximization of data for model generation, and allows the model to be applied when missing values are present. Trial registration number Not applicable
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