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PURPOSE: To explore the possible influence of sperm quality, as assessed by prewash total sperm count (TSC), on cumulative success rates in assisted reproduction cycles. METHODS: Retrospective study carried out in private IVF centre. Seven hundred sixty-five couples undergoing complete ICSI cycles, i.e. whose all embryos were transferred or disposed of. Couples were characterised by male infertility and female age younger than 36 years. Couples with a combination of female and male infertility factors were excluded. The primary outcome measure was cumulative live birth rate. Secondary outcomes were cumulative pregnancy and miscarriage rates. No specific interventions were made. RESULTS: Higher TSC values have a positive impact on cumulative success rates in cycles characterised by few retrieved oocytes (1 to 5), while does not influence the outcome of cycles with a normal (6 to 10) or high (> 10) number of retrieved oocytes. CONCLUSIONS: The study highlights the importance of sperm quality for the efficacy of assisted reproduction treatments. This influence may remain relatively cryptic in association with normal or high ovarian response, but emerge decisively in cases of reduced ovarian response, suggesting a relationship between ovarian response and oocyte ability to compensate for paternal-derived deficiencies. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10815-020-01807-5) contains supplementary material, which is available to authorized users.

Background: Despite a plethora of studies conducted so far, a debate is still unresolved as to whether TLM can identify predictive kinetic biomarkers or algorithms universally applicable. Therefore, this study aimed to elucidate if there is a relationship between kinetic variables and ploidy status of human embryos or blastocyst developmental potential. Methods: For conducting this retrospective cohort study, the normal distribution of data was verified using Kolmogorov-Smirnov test with the Lilliefors’ amendment and the Shapiro-Wilk test. Kinetic variables were expressed as median and quartiles (Q1, Q2, Q3, Q4). Mann-Whitney U-test was used to compare the median values of parameters. Univariate and multiple logistic regression models were used to assess relationship between blastocyst developmental potential or ploidy status and kinetics. Several confounding factors were also assessed. Results: Blastocyst developmental potential was positively correlated with the t4-t3 interval (s2) (OR=1.417, 95% CI of 1.288-1.560). s2 median value was significantly different between high- and low-quality blastocysts (0.50 and 1.33 hours post-insemination, hpi, respectively; p=0.003). In addition, timing of pronuclear appearance (tPNa) (OR=1.287; 95% CI of 1.131-1.463) had a significant relationship with ploidy changes. The median value of tPNa was statistically different (p=0.03) between euploid and aneuploid blastocysts (Euploid blastocysts=8.9 hpi; aneuploid blastocysts=10.3 hpi). Conclusion: The present findings are in line with the study hypothesis that kinetic analysis may reveal associations between cleavage patterns and embryo development to the blastocyst stage and ploidy status.

PURPOSE: To study embryo morphokinetics in relation to release in spent media of molecules with possible roles in development and implantation (miR-20a, miR-30c, and sHLA-G). METHODS: Data were obtained from embryos generated in standard IVF and ICSI cycles. The Eeva system was used for embryo assessment, based on early morphokinetic parameters and producing a score (1–5, best–worst) corresponding to higher/medium/lower chances of development to blastocyst. miRNAs — mm miR-20a-5p and miR-30c-5p — and sHLA-G were quantified in 25 μl of spent blastocyst media (SBM) collected before vitrification or transfer. Statistical analyses were performed applying Kolmogorov-Smirnov, Shapiro-Wilk, and Spearman’s correlation coefficient tests, where appropriate. RESULTS: SBM were collected from a total of 172 viable blastocysts. Their analysis showed that concentration of miR-20a was progressively lower as Eeva score increased and probability of development to blastocyst decreased (P = 0.016). The opposite trend was observed in the case of miR-30c, i.e., concentration was higher as score increased and chances of development to blastocyst decreased (P = 0.004). Analysis of sHLA-G revealed a negative correlation with Eeva score, i.e., levels were progressively lower as Eeva score increased and probability of development to blastocyst decreased (R = − 0.388, N = 141, P = 0.001). CONCLUSION: Our data suggest that morphokinetic algorithms that predict development to blastocyst stage, in fact, also identify embryos with molecular and cellular profiles more consistent with developmental functions. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10815-021-02162-9.

The sperm is essential for reconstitution of embryonic diploidy and highly specialized developmental functions. Immediately after gamete fusion, the sperm-borne PLC-zeta triggers activation, generating intracellular free Ca2+ oscillations. Mutations in the PLC-zeta encoding gene are associated with the absence of this factor in mature sperm and inability to achieve fertilization. Sperm play also a role in the greater game of the choreography of fertilization. In the human, the sperm centrioles are introduced into the oocyte environment with gamete fusion. They interact with the oocyte cytoskeletal apparatus to form a functional pair of centrosomes and ultimately regulate pronuclear juxtaposition in preparation for the first cleavage. As a consequence, the fidelity of chromosome segregation during the first cell divisions depends on the function of sperm centrioles. Sperm DNA integrity is essential for embryo development and health. Damaged DNA does not impact on the sperm fertilization ability following ICSI. However, detrimental effects emerge at pre- and post-implantation stages. Sperm-specific epigenetic factors also play an active role in the regulation of embryonic development, as shown by correlations between reduced embryo morphological quality and incorrect chromatin packaging during spermiogenesis or abnormal methylation of sperm CpG islands. This functional landscape demonstrates that the contribution of the sperm to development goes far beyond its well-established role in fertilization. Clinical studies confirm this view and indicate sperm function as a crucial aspect of research to increase the efficacy of assisted reproduction treatments.

PURPOSE: In this study, we tested the hypothesis that, in PGT-A cycles, decreased semen quality is associated with increased rates of mosaic blastocysts. METHODS: In a retrospective analysis, three hundred and forty PGT-A cycles are divided into study groups according to semen quality. Cycles were initially divided into two groups, discerning couples with absence of male factor of infertility (non-male factor: NMF; N = 146 cycles) from couples with a male factor of infertility (MF; N = 173 cycles). Couples with severe male factor (SMF) infertility (n = 22) were assessed separately. Embryos were cultured to the blastocyst stage and chromosomally assessed by array comparative genomic hybridization (aCGH). The study did not involve specific interventions. RESULTS: The reproductive outcome of MF and NMF groups did not indicate statistically significant differences. However, while no differences were found between MF and NMF groups in terms of euploid or aneuploid blastocysts rates, a significantly higher rate of mosaic blastocysts was observed in the MF group (3.6% vs. 0.5%, respectively; P = 0.03). A similar pattern of results was observed in the SMF group when compared with those of the other PGT-A cycles taken together (no SMF). In particular, a significantly higher rate of mosaic blastocysts was observed in the SMF group (7.7% and 1.8%, respectively; P = 0.008). CONCLUSIONS: The study outcome strongly suggests that compromised semen quality is associated with increased rates of mosaic blastocysts analysed in PGT-A cycles. Sperm assessment appears therefore as an important factor in the determination of embryo development and for a more precise prognostic assessment of PGT-A cases. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10815-019-01584-w) contains supplementary material, which is available to authorized users.

In the female reproductive tract, male gametes undergo a natural sperm selection process in order to discriminate spermatozoa on the basis of their quality to maximize the chances of successful reproduction. With the introduction of assisted reproductive technology (ART), scientists and clinicians developed diverse sperm selection strategies focusing on the isolation of competent spermatozoa. With increasing understanding of sperm functions and fertilization mechanism and evolution of available technologies, the initial simple sperm preparation protocols were complemented, and sometimes replaced, by new sperm-sorting techniques. In particular, while in the early years the focus was on obtaining motile spermatozoa, in later years, especially after the introduction of intracytoplasmic sperm injection (ICSI), the focus shifted to the isolation of functional and “healthy” spermatozoa, considering some other important factors, such as sperm DNA integrity. Sperm DNA damage, as well as chromatin structure alterations, in fact, is related to decreased reproductive ability of men, in natural as well as in assisted reproduction.

We read with interest the guideline proposed by Agarwal and colleagues (1) on clinical utility of sperm DNA fragmentation (SDF) testing. The Authors stated that, despite the clear association between SDF and male fertility, the clinical implication of SDF is poorly understood. So, the aim of the guideline was to underline the actual indications of SDF testing and also to explain the management of patients with increased SDF. To achieve this purpose, the Authors examined original and review articles concerning the significance of SDF testing and arranged their manuscript into two main sections: in the first part they described the current tests for SDF evaluation, underlining their basic principles as well as the main advantages and disadvantages; in the second part they performed an evidence-based analysis of the utility of SDF tests under specific clinical scenarios, commonly found by urologists and reproductive specialists. In particular, in the clinical scenario #1 varicocele was analyzed: Agarwal and colleagues stated that SDF testing may allow to better select varicocelectomy candidates among patients with clinical varicocele and borderline to normal sperm characteristics. In clinical scenario #2 the authors considered the unexplained infertility, suggesting performing SDF testing in couples with recurrent spontaneous abortion (RSA) or before starting intrauterine insemination (IUI). Clinical scenario #3 described the relationship between SDF and assisted reproduction techniques (ART), recommending the SDF analysis in patients with recurrent ART failures. Finally, in clinical scenario #4 the influence of lifestyle risk factors on male fertility was considered, suggesting offering SDF testing to infertile men with evidence of this kind of exposure, in order to underline an eventual sperm DNA damage and/or to monitor the patient’s response to treatment.

To investigate whether the sperm fertilizing potential can be improved by selecting a non-apoptotic fraction using magnetic activated cell sorting (MACS), and to compare the results with the conventional swim-up method.Twenty five male patients attending the andrology laboratory for sperm DNA fragmentation analysis. The sperm were prepared by density gradient centrifugation (DGC) and subsequently divided into three aliquots. The first was further separated into Annexin V-negative (non-apoptotic) fraction using MACS, the second was further processed by swim-up, while the third was left unseparated as a control. The impact of the combination of DGC with the two sperm preparation techniques on sperm quality was evaluated by comparing 'rapid progressive' motility, normal morphology according to Tygerberg's strict criteria and DNA integrity (by terminal deoxynucleotide transferase-mediated dUTP nick-end labeling [TUNEL]) for each aliquot.Sperm preparation that combines DGC with conventional swim-up method can provide sperm of higher quality in terms of motility, morphology and extent of DNA fragmentation compared to the Annexin V-negative (non-apoptotic) fraction derived from the combination of DGC with MACS.Integrating MACS as a part of sperm preparation technique will not improve sperm fertilizing potential to the same extent as the traditional swim-up separation procedure.

Irregular cleavage divisions are expected to produce chromosomally deviant embryos. We investigated whether embryos from irregular cleavages could develop into euploid blastocysts, and, if so, whether any evidence existed of a self-correction mechanism of the embryo. We also investigated the role of different dynamic aspects of morula compaction in this process. A total of 791 embryos from 141 patients undergoing pre-implantation genetic screening were retrospectively analysed using a time-lapse imaging system, and multiple cell divisions were evaluated. A total of 276 embryos developed into blastocysts suitable for biopsy and chromosome screening through array-comparative genomic hybridization. As well as testing trophectoderm biopsy specimens for aneuploidy, excluded cells of 18 blastocysts, which developed from partially compacted morulas, were also analysed. Unique data on the developmental fate of embryos with cleavage abnormalities are presented, and a potential mechanism of 'aneuploidy rescue' is postulated through which mosaic embryos may form partially compacted morulas to exclude aneuploid cells. In addition, this process seems to be less efficient in older women. The data obtained also provide further evidence that excluded cells should not be used to infer the cytogenetic status of the embryo.

Purpose: To evaluate the association between sperm DNA integrity and chromosomes aneuploidies in a considerable population of infertile patients undergoing assisted reproductive treatment (109 male) characterized by both normal and abnormal semen parameters. Methods: In 109 infertile patients with normal and abnormal semen parameters, the assessments of sperm DNA fragmentation by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) and chromosome aneuploidy by fluorescence in situ hybridization (FISH) have been performed on the same semen sample. Sperm samples were collected by masturbation into sterile cups after 3-5 days of sexual abstinence, allowed to liquefy for 30 min at room temperature and then divided in two aliquots, one processed by double gradient centrifugation (DGC) and used for TUNEL assay, whereas the remained aliquot was left unprocessed and used for FISH test. Results: The main results indicate a significant positive correlation between sperm chromosome aneuploidies and DNA integrity in patients with abnormal semen parameters (R=0.516 p=0,000) and negative not significant correlation in patients with normal seminal parameters (R=-0.105, p=0.476). Conclusions: Assuming the positive correlation between the two biomarkers in patients with defective spermatogenesis, high DNA fragmentation index (DFI) could perhaps be indicator of high chromosome aneuploidies level, thus increasing the risk of generating aneuploid embryos. Therefore, a clinical strategy could probably be to integrate also the preimplantation genetic screening (PGS) in ART treatment plan, in addition to the evaluation of sperm DNA fragmentation and/or sperm chromosome aneuploidy, to avoid transfer of chromosomally abnormal embryos.

Hyaluronan has recently been employed in the development of a commercial diagnostic kit for assessing sperm maturity, the so-called sperm-hyaluronan-binding assay (HBA). The aim of this study was to evaluate the usefulness of this test, in addition to routine semen analysis, to identify patients with poor reproductive prognosis in conventional IVF. Furthermore, the ability of hyaluronan to select spermatozoa with low DNA fragmentation was investigated. A total of 60 IVF patients were analysed with regard to reproductive outcome, sperm parameters, HBA score and sperm DNA fragmentation. The DNA fragmentation analysis was performed using the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling assay on the total sperm population and on the hyaluronan-bound spermatozoa obtained from the same samples. No relationship between hyaluronan binding and fertilization, cleavage, good-quality embryos, implantation, clinical pregnancy, miscarriages and biochemical pregnancy rates was found. Otherwise, correlations between spermatozoa hyaluronan binding and morphology (P < 0.01) and a significant difference between DNA fragmentation of the total sperm population and DNA fragmentation of the hyaluronan-bound spermatozoa (P = 0.029) were found. The results underline the ability of hyaluronan to select spermatozoa with higher DNA integrity and morphology. Nevertheless, the clinical value of the HBA in the management of male infertility seems to be limited.

BACKGROUND: A protocol for the chromosomal analysis of sperm samples with a severely reduced number of sperm cells was designed. METHODS: A severe male factor condition was the main cause of infertility for 38 couples: 27 were oligoasthenoteratospermic (OAT) and 11 with non-obstructive azoospermia underwent testicular sperm extraction (TESE). A two-round fluorescence in situ hybridization (FISH) protocol was performed with probes specific for the chromosomes X, Y, 13, 15, 16, 17, 18, 21 and 22. The recording of the position of each sperm cell at the microscope allowed diagnosis of each spermatozoon for the nine tested chromosomes. RESULTS: A mean number of 122 ± 78.5 sperm were diagnosed per patient with an incidence of total abnormalities corresponding to 13.4%. X 2 -tests for the observed frequencies and goodness-of-fit test were highly significant in all cases. A significantly higher proportion of total aneuploidy was detected in 79% of the tested samples compared to the normal population. Testicular sperm were significantly more prone to aneuploidy than ejaculated sperm. CONCLUSIONS: The designed FISH protocol for the analysis of severe OAT and TESE sperm samples is reliable, implying that the studied sample is representative of the original population. In view of the high incidence of aneuploidy in most severe OAT and TESE sperm, the FISH analysis of pathological sperm samples can be routinely performed in order to estimate the chances of the paternal contribution to aneuploidy in the resulting embryos.

To date, several publications have focused their attention on a new method for observing spermatozoa called 'motile sperm organelle morphology examination' (MSOME), which enables the evaluation of the fine nuclear morphology of motile spermatozoa in real time at high magnification (>x6000). As a consequence, a new microinjection procedure called intracytoplasmic morphologically selected sperm injection (IMSI) has been developed. The aim of the present work is therefore to evaluate the efficacy of the IMSI technique in the light of the current literature, focusing attention on the potential clinical application of the selection of strictly morphologically normal spermatozoa in patients undergoing conventional intracytoplasmic sperm injection treatments. In addition, a brief analysis of preliminary data regarding the relationship between IMSI and assisted reproduction treatment outcome is presented.

Sperm protamine deficiency and DNA damage were analysed employing chromomycin A(3) (CMA(3)) staining and the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling assay, respectively, in 132 patients (82 IVF, 50 intracytoplasmic sperm injection [ICSI]). The antioxidant ability of seminal plasma was analysed in 10 men, using the total oxidant scavenging capacity assay. A significant negative correlation was found between abnormal protamination and sperm parameters, including sperm DNA fragmentation (P0.01). A close relationship was found between sperm protamination and fertilization and pregnancy only in IVF (P = 0.004 and P0.04, respectively); in ICSI there was a correlation between DNA fragmentation and pregnancy (P = 0.031). Finally, there was a negative correlation between chromatin under-protamination and the antioxidant ability of seminal plasma (P0.01). Results of this study underline that, despite sperm abnormal protamination and DNA fragmentation being positively correlated, they affect the reproductive outcome in different ways: in particular there was good prognostic value for CMA(3) analysis only in IVF, whereas DNA fragmentation analysis was prognostic only for ICSI outcome. Data are also provided to support the idea of a relationship between defective antioxidant system activity and impairment of chromatin packaging.