Parental methylome reprogramming in human uniparental blastocysts reveals germline memory transition.

Uniparental embryos derived from only the mother (gynogenetic [GG]) or the father (androgenetic [AG]) are unique models for studying genomic imprinting and parental contributions to embryonic development. Human parthenogenetic embryos can be obtained following artificial activation of unfertilized oocytes, but the production of AG embryos by injection of two sperm into one denucleated oocyte leads to an extra centriole, resulting in multipolar spindles, abnormal cell division, and developmental defects. Here, we improved androgenote production by transferring the male pronucleus from one zygote into another haploid androgenote to prevent extra centrioles and successfully generated human diploid AG embryos capable of developing into blastocysts with an identifiable inner cell mass (ICM) and trophectoderm (TE). The GG embryos were also generated. The zygotic genome was successfully activated in both the AG and GG embryos. DNA methylome analysis showed that the GG blastocysts partially retain the oocyte transcription-dependent methylation pattern, whereas the AG blastocyst methylome showed more extensive demethylation. The methylation states of most known imprinted differentially methylated regions (DMRs) were recapitulated in the AG and GG blastocysts. Novel candidate imprinted DMRs were also identified. The production of uniparental human embryos followed by transcriptome and methylome analysis is valuable for identifying parental contributions and epigenome memory transitions during early human development.

Publisher Correction: Chromatin analysis in human early development reveals epigenetic transition during ZGA.

In this Letter, the 'Open chromatin' label in Fig. 4a should have been centred above the first three columns, and the black horizontal line underneath the label should have been removed. In addition, there should have been a vertical black line between the last two sets of panels for consistency. Minor changes have also been made to Fig. 1 and to the legend of Fig. 3. These errrors have been corrected online, and see Supplementary Information to the accompanying Amendment for the original Fig. 4.

Chromatin analysis in human early development reveals epigenetic transition during ZGA.

Upon fertilization, drastic chromatin reorganization occurs during preimplantation development 1 . However, the global chromatin landscape and its molecular dynamics in this period remain largely unexplored in humans. Here we investigate chromatin states in human preimplantation development using an improved assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) 2 . We find widespread accessible chromatin regions in early human embryos that overlap extensively with putative cis-regulatory sequences and transposable elements. Integrative analyses show both conservation and divergence in regulatory circuitry between human and mouse early development, and between human pluripotency in vivo and human embryonic stem cells. In addition, we find widespread open chromatin regions before zygotic genome activation (ZGA). The accessible chromatin loci are readily found at CpG-rich promoters. Unexpectedly, many others reside in distal regions that overlap with DNA hypomethylated domains in human oocytes and are enriched for transcription factor-binding sites. A large portion of these regions then become inaccessible after ZGA in a transcription-dependent manner. Notably, such extensive chromatin reorganization during ZGA is conserved in mice and correlates with the reprogramming of the non-canonical histone mark H3K4me3, which is uniquely linked to genome silencing3-5. Taken together, these data not only reveal a conserved principle that underlies the chromatin transition during mammalian ZGA, but also help to advance our understanding of epigenetic reprogramming during human early development and in vitro fertilization.

Effective protection: the embryonic development and clinical outcomes of emergency vitrification of 1246 oocytes and Day 0-Day 5 embryos in a natural disaster.

STUDY QUESTION: Can emergency vitrification protect embryos and oocytes during natural disasters or other events that prevent normal practice to achieve satisfactory embryonic development and clinical outcomes at a later time? SUMMARY ANSWER: Emergency vitrification of oocytes and Day 0-Day 5 (D0-D5) embryos during disasters is a safe and effective protective measure. WHAT IS KNOWN ALREADY: When some destructive events such as floods, earthquakes, tsunamis, and other accidents occur, emergency vitrification in embryo laboratories to protect human embryos, oocytes, and sperm is one of the important measures of an IVF emergency plan. However, there are few detailed reports on emergency vitrification in a state of disaster, especially about oocytes and D0 zygotes. Therefore, the effectiveness and safety of emergency vitrification of oocytes and D0-D5 embryos in disaster states are still unclear. STUDY DESIGN, SIZE, DURATION: A retrospective study was made in the Reproductive Medicine Center of the First Affiliated Hospital of Zhengzhou University from January 2018 to November 2022. The record rainstorms in Zhengzhou, China, caused severe flooding, traffic disruptions, and power outages. From 17:30, 20 July 2021 to 17:30, 21 July 2021, 1246 oocytes and D0-D5 embryos of 155 patients were vitrified whilst the laboratory had only an emergency power supply. PARTICIPANTS/MATERIALS, SETTING, METHODS: As of 21 December 2021, 1149 emergency vitrified oocytes and D0-D5 embryos of 124 patients underwent frozen-thawed embryo transfer (FET). They were divided into the following four groups according to the days of embryo culture in vitro: oocyte group, Day 0-Day 1 (D0-D1) group, Day 2-Day 3 (D2-D3) group, and Day 4-Day 5 (D4-D5) group. Control groups for each were selected from fresh cycle patients who underwent IVF/ICSI from January 2018 to October 2021. Control and emergency vitrification patients were matched on criteria that included age, fertilization method, days of embryonic development, and number and grade of transferred embryos. A total of 493 control patients were randomly selected from the eligible patients and matched with the emergency vitrification groups in a ratio of 4:1. The results of assisted reproduction and follow-up of pregnancy were analyzed. The embryonic development, clinical outcomes, and birth outcomes in each group were statistically analyzed. MAIN RESULTS AND THE ROLE OF CHANCE: A significant difference was observed in fertilization rate (81% versus 72%, P = 0.022) between the oocyte group and the control group. Significant differences were also observed in the monozygotic twin pregnancy rate (10% versus 0%, P = 0.038) and ectopic pregnancy rate (5% versus 0%, P = 0.039) between the D0-D1 group and the control group. No significant differences (P > 0.05) were observed between vitrified oocytes/D0-D1 embryos/D2-D3 embryos and the control group on the number of high-quality embryos (3.17 ± 3.00 versus 3.84 ± 3.01, P = 0.346; 5.04 ± 3.66 versus 4.56 ± 2.87, P = 0.346; 4.85 ± 5.36 versus 5.04 ± 4.64, P = 0.839), the number of usable blastocysts (1.22 ± 1.78 versus 1.21 ± 2.03, P = 0.981; 2.16 ± 2.26 versus 1.55 ± 2.08, P = 0.090; 2.82 ± 3.23 versus 2.58 ± 3.32, P = 0.706), clinical pregnancy rate (56% versus 57%, P = 0.915; 55% versus 55%, P = 1.000; 40% versus 50%, P = 0.488), miscarriage rate (30% versus 15%, P = 0.496; 5% versus 11%, P = 0.678; 17% versus 20%, P = 1.000), and live birth rate (39% versus 49%, P = 0.460; 53% versus 50%, P = 0.772; 33% versus 40%, P = 0.635). No significant differences (P > 0.05) were observed between the D4-D5 group and the control group on clinical pregnancy rate (40% versus 55%, P = 0.645), miscarriage rate (0% versus 18%, P = 1.000), and live birth rate (40% versus 45%, P = 1.000). LIMITATIONS, REASONS FOR CAUTION: The retrospective study design is a limitation. The timing and extent of natural disasters are unpredictable, so the sample size of vitrified oocytes, zygotes, and embryos is beyond experimental control. WIDER IMPLICATIONS OF THE FINDINGS: This study is the first study analyzing embryonic development, clinical outcomes, and birth outcomes of large samples of oocytes, D0 zygotes, and D1-D5 embryos after emergency vitrification under the disaster conditions. The results show that emergency vitrification is a safe and effective protective measure applicable to oocytes and D0-D5 embryos. The embryology laboratories need to be equipped with an emergency uninterrupted power supply capable of delivering for 6-8 h at full load. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the National Natural Science Foundation of China (grant 81871206). The authors declare that they have no conflicts of interest. All authors have completed the ICMJE Disclosure form. TRIAL REGISTRATION NUMBER: N/A.

The reference value of anti-Müllerian hormone to diagnose polycystic ovary syndrome is inversely associated with BMI: a retrospective study.

BACKGROUND: This study aimed to evaluate the cut-off value of anti-Müllerian hormone (AMH) combined with body mass index (BMI) in the diagnosis of polycystic ovary syndrome (PCOS) and polycystic ovary morphology (PCOM). METHODS: This retrospective study included 15,970 patients: 3775 women with PCOS, 2879 women with PCOM, and 9316 patients as controls. Multivariate logistic regression analysis was used to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for AMH. We randomly divided the patients into two data sets. In dataset 1, a receiver operating characteristic (ROC) curve was generated to analyze the accuracy of basic AMH levels in diagnosing PCOS and PCOM. The optimal cut-off value was calculated in dataset 1 and validated in dataset 2, expressed as sensitivity and specificity. RESULTS: In the PCOS group, obese patients had the lowest AMH levels, while underweight patients had the highest AMH level (P < 0.001). After adjusting for age, the ratio of luteinizing hormone (LH) and follicle stimulating hormone (FSH), serum testosterone level, and BMI, AMH was an independent predictor of PCOS and PCOM. In the group with BMI < 18.5 kg/m2, the optimistic AMH cut-off value was 5.145 ng/mL with a sensitivity of 84.3% and specificity of 89.1%, whereas in the BMI ≥ 28 kg/m2 group, the optimistic AMH cut-off value was 3.165 ng/mL with a sensitivity of 88.7% and specificity of 74.6%. For the BMI range categories of 18.5-24, 24.0-28 kg/m2, the optimistic AMH cut-off values were 4.345 ng/mL and 4.115 ng/mL, respectively. The tendency that the group with lower weight corresponded to higher AMH cut-off values was also applicable to PCOM. In the same BMI category, patients with PCOM had a lower AMH diagnosis threshold than those with PCOS (< 18.5 kg/m2, 5.145 vs. 4.3 ng/mL; 18.5-24 kg/m2, 4.345 vs. 3.635 ng/mL; 24.0-28 kg/m2, 4.115 vs. 3.73 ng/mL; ≥ 28 kg /m2, 3.165 vs. 3.155 ng/mL). These cut-off values had a good diagnostic efficacy in the validation dataset. Based on different phenotypes and severity of ovulation disorders, the distribution of AMH in PCOS were also significantly different (P < 0.001). CONCLUSIONS: AMH is a potential diagnostic indicator of PCOS and is adversely associated with BMI. The AMH cut-off value for diagnosing PCOS was significantly higher than that for PCOM.

Are ovarian responses and the number of transferable embryos different in females and partners of male balanced translocation carriers?

PURPOSE: To compare ovarian response and the number of transferable embryos between women with balanced autosomal translocations and women whose partners carry the translocation (control group). To investigate the predictive value of metaphase II (MII) oocyte number and biopsied embryo number for gaining at lowest one transferable embryo. DESIGN: We retrospectively analyzed 1942 preimplantation genetic testing for structural rearrangements (PGT-SR) cycles of 1505 balanced autosomal translocation couples over 8 years. All cycles were divided into two subgroups: Robertsonian and reciprocal translocations (ROBT and ReBT). Receiver operator characteristic (ROC) curves were plotted to ascertain a cutoff of MII oocytes and biopsied embryos as predictors of gaining at lowest one transferable embryo. RESULT: There were no statistical differences in baseline features or ovarian response indicators regarding the number of retrieved/MII oocytes, E2 level on the day of HCG, and ovarian sensitivity index (OSI) between women with balanced autosomal translocations and control group (P > 0.05). A decreased number of transferable embryos were found in women with balanced autosomal translocations regardless of the type of translocation. The cutoff values for gaining at lowest one transferable embryo are 12.5 MII oocytes and 4.5 biopsied embryos, respectively. CONCLUSION: Women with balanced autosomal translocations have a normal ovarian response, but fewer transferable embryos, meaning that higher gonadotropin (Gn) doses may be required to increase transferable embryos. When fewer than 12.5 MII oocytes or 4.5 blastocysts are obtained in a PGT-SR cycle, couples should be notified that the likelihood of gaining a transferable embryo is low.

Lower chromosomal abnormality frequencies in miscarried conceptuses from frozen blastocyst transfers in ART.

STUDY QUESTION: Are blastocyst culture and cryopreservation in ART associated with chromosomal abnormalities in miscarried products of conception (POC)? SUMMARY ANSWER: Frozen blastocyst transfer in women aged 35 years or older and frozen embryo transfer (ET) (including both cleavage-stage embryo and blastocyst) in women aged <35 years are associated with decreased frequencies of embryonic chromosomal abnormalities in miscarried POC. WHAT IS KNOWN ALREADY: Blastocyst culture and embryo cryopreservation have been previously associated with favorable ART treatment outcomes and widely applied in clinical practice. However, the association between these embryo manipulation procedures and embryonic chromosomal abnormalities has not been evaluated to the best of our knowledge. STUDY DESIGN, SIZE, DURATION: This retrospective study included a total of 720 patients who underwent IVF/ICSI, and the retained POC were obtained. A single-nucleotide polymorphism (SNP)-based chromosomal microarray analysis (CMA) of all miscarried conceptuses was performed. PARTICIPANTS/MATERIALS, SETTING, METHODS: This study was based on the Clinical Reproductive Medicine Management System/Electronic Medical Record Cohort Database (CCRM/EMRCD) at our center. In total, 720 miscarried POCs were collected from patients undergoing ART (including fresh cleavage-stage ET, fresh blastocyst transfer, frozen cleavage-stage ET and frozen blastocyst transfer), and the incidences and profiles of cytogenetic abnormalities in the miscarried conceptuses were measured via SNP-based CMA. MAIN RESULTS AND THE ROLE OF CHANCE: The chromosomal abnormality rate in POC varied from 33.7% to 66.7% among the different ET strategies. In the patients aged ≥35 years, frozen blastocyst transfer was significantly associated with a lower incidence of chromosomal aberrations in the POCs (adjusted odds ratio (aOR): 0.171 (95% CI: 0.040-0.738); P = 0.018) than fresh blastocyst transfer. In the patients aged <35 years, frozen ET was significantly associated with a lower incidence of chromosomal aberrations than fresh ET in both cleavage-stage ET cycles and blastocyst transfers cycles (aOR: 0.545 (0.338-0.879), P = 0.013; and aOR: 0.357 (0.175-0.730), P = 0.005, respectively). Trisomy was the most frequent abnormal embryonic karyotype in the different ET strategies, and its frequency significantly differed among strategies (P < 0.05). LIMITATIONS, REASONS FOR CAUTION: This study was retrospectively designed, and we cannot draw any definite conclusions from our results regarding the adequate safety of embryo cryopreservation in ongoing pregnancy. WIDER IMPLICATIONS OF THE FINDINGS: To our knowledge, this is the first study assessing the associations of ET strategies with the probability of miscarriage associated with embryonic chromosomal abnormalities. However, the underlying mechanism of these associations is unknown; this study may promote research concerning ET strategies and promote comprehensive consultations and recommendations for patients. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Natural Science Foundation of China (Grant No.81571409), Science and Technology Research Project of Henan (Grant No. 172102310009) and Medical Science and Technology Research Project of Henan (Grant No. 201701005). The authors declare no competing interests. TRIAL REGISTRATION NUMBER: N/A.

[The level of the stress biomarker salivary alpha amylase is correlated with semen quality in infertile young men].

Objective: To investigate the relationship between the level of the stress biomarker salivary alpha amylase (SAA) and semen quality in infertile young men. METHODS: Totally, 313 infertile and 96 normal healthy men, aged 20－40 years old, were enrolled in this study. The SAA levels and semen parameters of the subjects were measured and compared between the two groups. RESULTS: Compared with the normal healthy controls, the young infertility patients showed a significantly higher SAA level (ï¼»141.04 ± 44.13ï¼½ vs ï¼»151.48 ± 38.42ï¼½ µmol/L, P < 0.05) and percentage of immotile sperm (IMS) (ï¼»39.98 ± 14.53ï¼½% vs ï¼»64.48 ± 26.32ï¼½%, P < 0.05), but lower sperm concentration (ï¼»44.23 ± 21.63ï¼½ vs ï¼»32.42 ± 23.07ï¼½ ×106/ml, P < 0.05) and percentage of progressively motile sperm (PMS) (ï¼»52.13 ± 15.42ï¼½% vs ï¼»27.91 ± 21.22ï¼½%, P < 0.05). Sperm concentration (ï¼»26.33 ± 31.83ï¼½ vs ï¼»35.28 ± 27.70ï¼½ ×106/ml, P < 0.05) and the percentage of PMS were remarkably lower in the infertile men with a high than in those with a low SAA level (ï¼»19.85 ± 21.55ï¼½% vs ï¼»31.70 ± 20.02ï¼½%, P < 0.05), while the percentage of IMS was higher in the former than in the latter group (ï¼»74.19 ± 26.84ï¼½% vs ï¼»59.92 ± 24.85ï¼½%, P < 0.05). The SAA level in the young infertility patients was correlated positively with the percentage of IMS (r = 0.170, P < 0.01), but negatively with sperm concentration (r = －0.227, P < 0.01) and the percentage of PMS (r = －0.468, P < 0.01). CONCLUSIONS: The stress biomarker salivary alpha amylase level in infertile young men is negatively correlated with semen quality, and therefore semen parameters can be improved by reducing the stress level.

Melatonin attenuates postovulatory oocyte dysfunction by regulating SIRT1 expression.

The quality of postovulatory metaphase II oocytes undergoes a time-dependent deterioration as a result of the aging process. Melatonin is considered to be an anti-aging agent. However, the underlying mechanisms of how melatonin improves the quality of postovulatory aged oocytes remain largely unclear. In this study, by using mouse model, we found that there were elevated reactive oxygen species levels and impaired mitochondrial function demonstrated by reduced mitochondrial membrane potential and increased mitochondrial aggregation in oocytes aged 24 h, accompanied by an increased number of meiotic errors, unregulated autophagy-related proteins and early apoptosis, which led to decreased oocyte quality and disrupted developmental competence. However, all of these events can be largely prevented by supplementing the oocyte culture medium with 10-3 M melatonin. Additionally, we found that the expression of sirtuin family members (SIRT1, 2 and 3) was dramatically reduced in aged oocytes. In addition, in vitro supplementation with melatonin significantly upregulated the expression of SIRT1 and antioxidant enzyme MnSOD, but this action was not observed for SIRT2 and SIRT3. Furthermore, the protective effect of melatonin on the delay of oocyte aging vanished when the SIRT1 inhibitor EX527 was used to simultaneously treat the oocytes with melatonin. Consistent with this finding, we found that the postovulatory oocyte aging process was markedly attenuated when the oocytes were treated with the SIRT1 activator SRT1720. In conclusion, our data strongly indicate that melatonin delays postovulatory mouse oocyte aging via a SIRT1-MnSOD-dependent pathway, which may provide a molecular mechanism support for the further application of melatonin in the assisted reproductive technology field.

Comparison of differences in development potentials between frozen-thawed D5 and D6 blastocysts and their relationship with pregnancy outcomes.

PURPOSE: Whether there are differences in the pregnancy outcomes of blastocysts cryopreserved during different developmental stages remains under debate because the results among studies are inconsistent. We analyzed blastocyst quality and pregnancy outcomes by considering blastocyst euploidy and investigated the differences in the development potential between blastocysts of different developmental stages (frozen-thawed day 5 [D5] and day 6 [D6] cycles) and their relationship with clinical pregnancy outcomes. METHODS: In total, 1374 D5 and 255 D6 frozen-thawed blastocyst transfer cycles were retrospectively analyzed. Additionally, the chromosome euploidy and clinical pregnancy rates of 237 blastocysts from 50 pre-implantation genetic diagnosis (PGS) cycles were statistically analyzed. The corresponding euploidy rate and pregnancy outcomes of the D5 and D6 blastocyst transfers were also compared. RESULTS: The clinical pregnancy rate (47.2 vs 40.0 %; P = 0.04) and implantation rate (34.2 vs 28.8 %; P = 0.03) of the D5 blastocysts were higher than were those of the D6 blastocysts. However, the clinical pregnancy rate (52.4 vs 52.6 %; P = 0.97) and implantation rate (38.9 vs 35.6 %; P = 0.39) of the high-quality D5 blastocysts did not significantly differ from those of the high-quality D6 blastocysts. Analysis of blastocyst euploidy in 237 blastocysts examined in 50 PGS cycles showed that the euploidy rates of the D5 and D6 blastocysts were both 48.1 % (P = 0.99). The clinical pregnancy rate of the D5 blastocysts (48.5 vs 17.6 %; P = 0.03) was higher than that of the D6 blastocysts. The euploidy rates (55.2 vs 55.3 %; P = 0.99) and clinical pregnancy rates (60.0 vs 42.9 %; P = 0.77) of the high-quality D5 and D6 blastocysts did not differ. The euploidy rate (55.3 vs 41.5 %, P = 0.03) and clinical pregnancy rate (54.5 vs 25.0 %, P = 0.03) of the high-quality blastocysts were higher than were those of the poor-quality blastocysts. CONCLUSIONS: The euploidy rates between the D5 and D6 blastocysts did not differ. High-quality D6 blastocysts in frozen-thawed cycles had similar developmental potential and pregnancy outcomes compared to those of high-quality D5 blastocysts. The quality of the blastocysts was an important factor that affected the pregnancy outcomes of the frozen-thawed cycles.

Sperm telomere length is positively associated with the quality of early embryonic development.

STUDY QUESTION: What is the relationship between telomere length in sperm and early embryonic development in in vitro fertilization (IVF)? SUMMARY ANSWER: Sperm telomere length (STL) is positively associated with embryo quality in IVF. WHAT IS KNOWN ALREADY: Previous studies have shown that STL differs among human males. STUDY DESIGN, SIZE, DURATION: In order to determine the associations between STL, fertilization laboratory parameters and clinical pregnancy in IVF, 418 couples were recruited from August 2013 to August 2014. MATERIALS, SETTING, METHODS: We collected semen samples and used quantitative PCR technique to detect the mean STL for each patient. These data were compared with the IVF outcomes. MAIN RESULTS AND THE ROLE OF CHANCE: The mean STL was positively correlated with the age of patient (rP = 0.100; P = 0.041) and total sperm count/ejaculate (rp = 0.28; P < 0.001). Analysis of the age-adjusted mean STL in relation to the male patient's paternal and maternal ages at the time of his conception showed significant positive relationships between STL and both paternal (r = 0.16; P = 0.003) and maternal (r = 0.19; P < 0.001) ages at the time of conception. In addition, significant correlations were found between STL and good quality embryo (regression coefficient: 1.63; P < 0.001) and transplantable embryo rates (regression coefficient: 1.57; P < 0.001), but clinical pregnancy rates were not affected (odds ratio = 1.00 [95% CI: 0.93-1.07]; P = 0.90). LIMITATIONS, REASONS FOR CAUTION: This study showed that STL was positively associated with embryo quality in IVF. Additional studies are needed to confirm these observations. WIDER IMPLICATION OF THE FINDINGS: STL has the potential to be used as a marker for the prediction of embryonic quality. STUDY FUNDING/COMPETING INTERESTS: This work was supported by the National Natural Science Foundation of China (Grants 31271605 and 31471404), and the National Science Foundation for Young Scientists of China (Grant 31401274), and Science Foundation of First Affiliated Hospital of Zhengzhou University for Yong Scientists. The authors have declared that no competing interests exist.

Derivation of normal diploid human embryonic stem cells from tripronuclear zygotes with analysis of their copy number variation and loss of heterozygosity.

This study sought to establish archives of genetic copy number variation (CNV) in human embryonic stem cell (hESC) lines that are associated with known diseases. We collected patients' fresh, discarded zygotes from in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) protocols. A total of 208 fresh, tripronuclear, discarded zygotes were also collected in this study from patients on the third day of their treatment cycle, prior to transfer. The blastula-formation rates were 13.51% (26/192) and 26.7% (4/15) while the high-quality blastocyst formation rates were 5.8% (11/192) and 20% (3/15) in the IVF and ICSI groups, respectively. The inner cell mass (ICM) from each embryo was mechanically separated, and then grown on feeder layers consisting of mouse embryonic fibroblasts and human foreskin fibroblasts (a 1:1 mixture). The hESC karyotype was determined by traditional G-banding; analysis of the results for the Zh19P25 and Zh20P24 cell lines showed that both were 46 XY. CNV and loss-of-heterozygosity analysis of hESC gDNA was performed to assess the genetic characteristics associated with molecular diseases using the high-resolution Infinium High-Density HumanCytoSNP-12 DNA chip. Seven CNVs in Zh19P25 and Zh20P24 were deletions, and a region that corresponds to Potocki-Shaffer disease, 11p11.2-11p11.12 in Zh20P24, showed a 2.98-Mb loss. These data together suggest that single-nucleotide polymorphism (SNP) microarray analysis for molecular cytogenetic features can help to distinguish hESC lines with a normal karyotype from tripronuclear zygotes with known, disease-related characteristics.

Processing of semen by density gradient centrifugation selects spermatozoa with longer telomeres for assisted reproduction techniques.

The ends of eukaryotic chromosomes contain specialized chromatin structures called telomeres, the length of which plays a key role in early human embryonic development. Although the effect of sperm preparation techniques on major sperm characteristics, such as concentration, motility and morphology have been previously documented, the possible status of telomere length and its relation with sperm preparation techniques is not well-known for humans. The aim of this study was to investigate the role of density gradient centrifugation in the selection of spermatozoa with longer telomeres for use in assisted reproduction techniques in 105 samples before and after sperm processing. After density gradient centrifugation, the average telomere length of the sperm was significantly longer (6.51 ± 2.54 versus 5.16 ± 2.29, P < 0.01), the average motile sperm rate was significantly higher (77.9 ± 11.8 versus 44.6 ± 11.2, P < 0.01), but average DNA fragmentation rate was significantly lower (11.1 ± 5.9 versus 25.9 ± 12.9, P < 0.01) compared with raw semen. Additionally, telomere length was positively correlated with semen sperm count (rs = 0.58; P < 0.01). In conclusion, density gradient centrifugation is a useful technique for selection of sperm with longer telomeres.

The value of second polar body detection 4 hours after insemination and early rescue ICSI in preventing complete fertilisation failure in patients with borderline semen.

In this study we evaluated the value of short-time insemination and early rescue intra-cytoplasmic sperm injection (ICSI) in preventing the occurrence of complete fertilisation failure for mild or moderate male infertility patients. A total of 866 couples with borderline semen who underwent in vitro fertilisation treatment in 2010 were included. Regular insemination was performed between January and June of 2010 and short-term insemination was performed from July through December 2010, where, as early as 4h after insemination, oocytes were denuded from cumulus cells and extrusion of the second polar body was evaluated. Of the 4153 mature oocytes with a detectable second polar body 4 h after insemination, 3874 (93.3%) showed signs of fertilisation on Day 1. Where no second polar body was present in any of the retrieved oocytes for a given patient, rescue ICSI was performed immediately. Similar rates of normal fertilisation and percentage of good-quality embryos were obtained between early rescue ICSI and regular ICSI. Clinical pregnancy occurred in 16 of 43 patients (37.2%) receiving early rescue ICSI. Our results showed early rescue ICSI in combination with evaluation of the second polar body 4 h following insemination is an effective method to prevent complete fertilisation failure for patients with mild or moderate male infertility.

High AMH levels are associated with gestational hypertension in patients with PCOS who underwent IVF/ICSI-ET.

BACKGROUND: Patients with polycystic ovary syndrome (PCOS) have a higher risk of obstetric complications. The association between anti-Müllerian hormone (AMH) and gestational hypertension in these patients is poorly understood. OBJECTIVE: To determine the association between serum AMH levels and gestational hypertension in patients with PCOS undergoing fresh embryo transfer. METHODS: This retrospective study included 649 patients with PCOS who had singleton live births after undergoing fresh embryo transfers. The association of AMH with gestational hypertension in these patients was estimated before and after propensity score matching (PSM). RESULTS: Patients with gestational hypertension had higher AMH levels than those without gestational hypertension. In single-factor logistic regression, the odds of gestational hypertension increased by 11.7% and 18.6% for every 1 ng/mL increase in AMH before and after adjusting for confounding factors [OR 1.117, 95% CI(1.025, 1.217), P = 0.012; adjusted OR 1.186, 95% CI(1.061, 1.327), adjusted P = 0.003], respectively. The odds of gestational hypertension increased more than 100% [adjusted OR 2.635, 95% CI(1.132, 6.137), adjusted P = 0.025] in the 75th percentile group (>9.30 ng/ml) and more than thrice [adjusted OR 4.75, 95% CI(1.672, 13.495), adjusted P = 0.003] in the 90th percentile group (>12.31 ng/ml) as compared to the without-gestational hypertension group. AMH level was still associated with gestational hypertension after PSM. The area under the curve of AMH predicting gestational hypertension was 0.654 [95% CI (0.532, 0.776), P = 0.011] with an optimal cutoff value of 11.975 ng/mL. CONCLUSIONS: High serum AMH level pre-pregnancy (especially at levels > 9.30 ng/mL) indicates a high odds of gestational hypertension in patients with PCOS undergoing fresh embryo transfer.

Fertility preservation in male adolescents with cancer (2011-2020): A retrospective study in China.

BACKGROUND: According to the studies, more than 80% of pediatric patients with cancer can achieve a survival rate greater than 5 years; however, long-term chemotherapy and/or radiation therapy may seriously affect their reproductive ability. Fertility preservation in adolescents with cancer in China was initiated late, and related research is lacking. Analyze data to understand the current situation and implement measures to improve current practices. METHODS: From 2011 to 2020, data on 275 male adolescents with cancer whose age ranged from 0 to 19 years old were collected from 16 human sperm banks for this retrospective study. Methods include comparing the basic situation of male adolescents with cancer, the distribution of cancer types, and semen quality to analyze the status of fertility preservation. RESULTS: The mean age was 17.39 ± 1.46 years, with 13 cases (4.7%) aged 13-14 years and 262 cases (95.3%) aged 15-19 years. Basic diagnoses included leukemia (55 patients), lymphomas (76), germ cell and gonadal tumors (65), epithelial tumors (37), soft tissue sarcomas (14), osteosarcoma (7), brain tumors (5), and other cancers (16). There are differences in tumor types in different age stages and regions. The tumor type often affects semen quality, while age affects semen volume. Significant differences were found in sperm concentration and progressive motility before and after treatment (p < 0.001). Moreover, 90.5% of patients had sperm in their semen and sperm were frozen successfully in 244 patients (88.7%). CONCLUSIONS: The aim of this study is to raise awareness of fertility preservation in male adolescents with cancer, to advocate for fertility preservation prior to gonadotoxic therapy or other procedures that may impair future fertility, and to improve the fertility status of future patients.

Effects of frozen timing on the spindle density, the angle between the polar body and spindle, and embryo development of intracytoplasmic sperm injection in mouse mature oocytes.

Better pregnancy outcomes can be obtained by human mature oocyte vitrification, but many problems remain to be resolved in human mature oocyte vitrification. Since mature oocyte development possesses its own maturity cycle, there should be the optimal timing for mature oocyte vitrification. The purpose of this study was to observe the effects of frozen timing on the spindle density, the angle between the polar body and spindle, and embryo development of intracytoplasmic sperm injection (ICSI) in vitrified mouse mature oocytes and explore its possible mechanism. Mouse oocytes were randomly divided into three groups according to different frozen timing including Groups A, B, and C in which oocytes were vitrified within 2 h after ovum pick-up, and 3-4 and 5-6 h after ovum pick-up, respectively. Spindle-related parameters were measured, ICSI was performed. The spindle occurrence rate of vitrified-thawed oocytes was 98.4% in Group A, 82.3% in Group B, and 75.8% in Group C, without statistical differences between pre-vitrification and post-thawing and among the three groups (P > 0.05). The angles between the polar body and spindle were larger after thawing than before vitrification (P < 0.01). The spindle retardance values were lower after thawing than before vitrification in Groups B and C (P < 0.05), but higher in Group A (P < 0.05). The spindle retardance values before vitrification were higher in Group B than in Groups A and C (P < 0.05), but the spindle retardance value, oocyte survival and two-cell rate after thawing were higher in Group A than in Groups B and C (P < 0.05). There were no statistical differences in ICSI fertility rate between the three groups (P > 0.05). The damage on the spindle is the slightest and embryo quality is the highest in the mouse oocytes vitrified within 2 h after ovum pick-up. The spindle retardance value is more valuable than the spindle occurrence rate in the evaluation of vitrified-thawed oocyte quality, and is positively correlated with embryo quality.

Effects of human cumulus cells on in vitro fertilization outcomes and its significance in short-term insemination.

OBJECTIVE: To observe the effects of cumulus cells on in vitro fertilization. STUDY DESIGN: Oocytes were retrieved from 47 patients (> 10/patient) who underwent short-term insemination from August 2009 to June 2010. The oocytes from each patient were divided into a cumulus cell-free group (cumulus cells were removed from the incubation medium 4 hours after coincubation of male and female gametes) with 389 oocytes and a cumulus cell group (cumulus cells were retained with the gametes until fertilization was evaluated 16-18 hours after co-incubation) with 402 oocytes. RESULTS: Polyspermic fertilization was 0.96 +/- 1.14 in the cumulus cell-free group and 0.47 +/- 0.72 in the cumulus cell group with p < 0.05. There were no significant differences in normal fertilization (5.96 g 1.73 vs. 6.55 +/- 3.72), 1PN fertilization (0.06 +/- 0.25 vs. 0.09 +/- 0.28), fertilization failure (1.34 +/- 1.17 vs. 1.45 +/- 1.84), cleavage (6.06 +/- 2.04 vs. 6.51 +/- 3.94), high-quality embryo (3.94 +/- 1.79 vs. 4.74 +/- 3.45) and usable embryo (5.06 +/- 1.86 vs. 5.68 +/- 3.98) between cumulus cell-free group and cumulus cell group, all with p > 0.05. CONCLUSION: In our study short-term insemination (4 hours) causes a statistical increase in polyspermic fertilization. In order to ensure correct oocyte fertilization and reduction of polyspermic fertilization, it is better to retain the cumulus cells for 16-18 hours.

Effect of modified single cell fixation method on cell-nuclear areas and fluorescence in-situ hybridization signals.

BACKGROUND: Fluorescence in situ hybridization (FISH) is an irreplaceable method in pre-implantation genetic diagnosis. We explored the effects of a modified single cell fixation method on the cell-nuclear area and FISH signal. METHODS: From January 2006 to March 2008, the blastomeres with marked nuclei from D3 embryos were selected. Cells were fixed with three different methods. The effects of the three methods on the cell-nuclear areas and FISH signals were then analyzed. RESULTS: The cell fixation rate was higher in conventional (Group B, 94.85%) and modified (Group C, 95.79%) Tween-20/HCl + methanol/glacial acetic acid methods than in the methanol/glacial acetic acid method (Group A, 86.73%) with p < 0.05. The complete signal rates in group A, B, and C were 95.3%, 93.5%, and 93.4%, respectively, with p > 0.05. The mean cell-nuclear areas in groups A, B, and C were 55.3, 46.2, and 49.5 microm3, respectively, with p < 0.05 in group A compared with group B or C, but with p > 0.05 between Group B and C. There was no significant difference in signal overlap and splitting rates between the three groups. CONCLUSIONS: Modified Tween-20/HCl + methanol/glacial acetic acid method fails to increase FISH signal overlap and splitting rates. It is simple and its fixation time is short. It can be widely used in clinical practice.

Effect of culture medium volume and embryo density on early mouse embryonic development: tracking the development of the individual embryo.

PURPOSE: To determine the optimal volume or density of embryos for the well-of-the-well (WOW) system in order to track the development of individual embryos and to determine whether the WOW system can reverse the negative impact of culturing embryos singly. METHODS: (1) Mouse embryos (groups of nine at the 2-cell stage) were cultured in 6.25 µl, 12.50 µl, 25.00 µl and 50.00 µl of droplets of culture medium under paraffin oil; (2) Groups of three, six, nine and twelve embryos at the 2-cell stage were cultured in 50 µl of droplet of culture medium under paraffin oil; (3) Groups of nine embryos at the 2-cell stage were cultured in 50 µl of droplet under paraffin oil with or without nine micro-wells made on the bottom of the Petri dish into each of which were placed one of the nine embryos (WOW system). Also single 2-cell stage embryos was cultured individually in 5.5 µl of droplet of culture medium under paraffin oil with or without a single micro-well made on the bottom of the Petri dish (WOW system for single culture). At the end of culture, the percentages of blastocyst development, hatching and hatched blastocysts were compared in each group. The blastocysts were fixed for differential staining. RESULTS: The blastocyst development was significantly higher (P < 0.05) when nine embryos were cultured in 50 µl of droplet of culture medium compared with other volumes. The blastocyst development was significantly reduced (P < 0.05) in single embryo culture compared to group embryo culture with or without the WOW system. The blastocyst development was not improved when single embryo cultured individually in a micro-well was compared to single embryo cultured individually without micro-well. The total cell numbers of blastocysts were significantly higher in group embryo culture than single embryo culture regardless of whether the WOW system was used. In addition, the total cell numbers of blastocysts were significantly higher (P < 0.05) in single embryo culture with the WOW system than without. CONCLUSIONS: Group embryo culture is superior to single embryo culture for blastocyst development. The WOW system with 50 µl of droplet of culture medium can be used to track the individual development of embryo cultured in groups while preserving good embryonic development. The reduced embryonic development with single embryo culture cannot be ameliorated by the WOW system.