Innovative technology for evaluation of sperm DNA double-strand breaks diagnoses male factor infertility and prevents reproductive failures.

Neutral comet assay has been available for two decades to evaluate sperm double-strand breaks (DSBs). However, its clinical usability is limited due to its complex and time-consuming procedure, as well as the lack of a standardized scoring system. The aim of this study was to: develop a rapid diagnostic method for DSBs, Sperm DNA Fragmentation Releasing Assay (SDFR), and explore the association between DSBs and reproductive outcomes. We pioneered the use of polyacrylamide (PA) for embedding sperm chromatin and optimized the porosity of PA to be between 10 and 13%. The refined PA network allowed the trapping of DSBs, which dispersed halo on an immunological slide; in contrast, intact chromatin failed to develop a halo. A strong correlation was showed between reproducible values obtained from SDFR and neutral comet assay. SDFR were responsive to dose-/time-dependent simulated DSBs, indicating high sensitivity and specificity. Furthermore, we conducted a retrospective study of couples with embryonic aneuploidy screening, and recording DSB profiles of the male partners. Our findings revealed that DSB enabled to predict embryonic aneuploidy whereas basic semen parameters did not. In conclusion, SDFR offers a rapid and user-friendly approach for evaluating DSBs, with potential implications for predictive healthcare in reproductive medicine.

Live motile sperm sorting device for enhanced sperm-fertilization competency: comparative analysis with density-gradient centrifugation and microfluidic sperm sorting.

PURPOSE: A live motile sperm sorting device (LensHooke® CA0) developed to prevent the deleterious effects of centrifugation was evaluated comparatively with conventional density-gradient centrifugation (DGC) and microfluidic-based device (Zymot) in sperm selection. METHODS: Semen samples from 239 men were collected. CA0 under different incubation intervals (5, 10, 30, and 60 min) and temperatures (20, 25, and 37℃) was conducted. The sperm quality in CA0-, DGC-, and Zymot-processed samples was then comparatively evaluated. Semen parameters included concentration, motility, morphology, motion kinematics, DNA fragmentation index (DFI), and the rate of acrosome-reacted sperm (AR). RESULTS: Total motility and motile sperm concentration increased in a time- and temperature-dependent manner and the total motility peaked for 30 min at 37℃. In paired analysis, CA0 showed significantly higher total motility (94.0%), progressive motility (90.8%), rapid progressive motility (83.6%), normal morphology (10.3%), and lower DFI (2.4%) and AR (4.7%) than the other two methods in normozoospermic samples (all p < 0.05). For non-normozoospermic samples, CA0 had significantly better results than the other two methods (total motility 89.2%, progressive motility 80.4%, rapid progressive motility 74.2%, normal morphology 8.5%, DFI 4.0%, and AR 4.0%; all p < 0.05). CONCLUSION: CA0 yielded spermatozoa with enhanced sperm fertilization potentials; DFI was minimized in samples processed by CA0. CA0 was effective for both normal and abnormal semen samples due to its consistent selection efficiency.

Correlation of skin carotenoid levels with embryo development and pregnancy result of in vitro fertilization cycles for couples with unexplained infertility.

Oxidative stress-related DNA damage is a significant pathology for male subfertility and unexplained infertility (UI). Antioxidant supplement by food or nutrition may benefit sperm function of UI couples. However, the role of antioxidant status on fertilization outcome and embryo development for UI couples is not clear. A total of 63 semen samples from UI couples undergoing in vitro fertilization (IVF) treatment (26 pregnant cycles and 37 nonpregnant cycles) were recruited for this prospective observational study. The reactive oxygen species (ROS) levels of sperm cells are detected by a chemiluminescence assay. Total antioxidant capacity (TAC) of seminal plasma is evaluated according to an antioxidant assay kit. The skin carotenoid status in the male partners of UI couples is measured by resonance Raman spectroscopy to determine the antioxidant potential from dietary supplement. The skin carotenoid status (23,115 ± 6,831 vs. 19,432 ± 5,242 Raman intensity, p = .0329 by Mann-Whitney U test) and day 3 good embryo rates (49.6 ± 27.1% vs. 26.8 ± 23.1%, p = .002 by Mann-Whitney U test) are higher in pregnant cycles compared to those in nonpregnant cycles. The local antioxidant capacity (seminal TAC) is closely correlated with fertilization rates (r = .35, p = .005). In contrast, skin carotenoid status is intimately associated with good embryo rates in IVF cycles (r = .34, p = .007). In conclusion, the skin carotenoid status of male partners of UI couples may benefit embryo development and the subsequent pregnancy outcome of IVF treatment. Further investigation about the effect and mechanism of nutritional supplement on embryo development in IVF cycles for UI couples is deserved.

Interleukin-3 Polymorphism is Associated with Miscarriage of Fresh in Vitro Fertilization Cycles.

The aim of this study was to examine the association between interleukin (IL) genes polymorphisms and in vitro fertilization (IVF) outcome. A prospective cohort analysis was performed at a Women's Hospital IVF centre of 1015 female patients undergoing fresh non-donor IVF cycles. The effects of the following six single nucleotide polymorphisms (SNPs) in five IL genes on IVF outcomes were explored: IL-1α (rs1800587 C/T), IL-3 (rs40401 C/T), IL-6 (rs1800795 C/G), IL-15 (rs3806798 A/T), IL-18 (rs187238 C/G) and IL-18 (rs1946518 G/T). The main outcome measures included clinical pregnancy, embryo implantation, abortion and live birth rates. There were no statistically significant differences in clinical pregnancy, embryo implantation and live birth rates in the analysis of 1015 patients attempting their first cycle of IVF. Infertile women with IL-3 homozygous major genotype had a higher abortion rate than those with heterozygous and homozygous minor genotype (16.5% vs. 7.9%, P = 0.025). In conclusion, our results indicated that the IL-3 rs40401 polymorphism is associated with increased risk of abortion of IVF patients. Future studies with inclusion of other ethnic populations must be conducted to confirm the findings of this study.

Anti-Müllerian Hormone Gene Polymorphism is Associated with Clinical Pregnancy of Fresh IVF Cycles.

The aim of this study was to examine the effects of single-nucleotide polymorphisms (SNPs) in the anti-Müllerian hormone (AMH) and AMH type II receptor (AMHRII) genes on in vitro fertilization (IVF) outcomes. In this prospective cohort study, we genotyped the AMH 146 T > G, AMHRII -482 A > G and AMHRII IVS1 +149 T > A variants in 635 women undergoing their first cycle of controlled ovarian stimulation for IVF. DNA was extracted from the peripheral blood of all participants, and the SNPs were genotyped by real-time polymerase chain reaction. The distributions, frequencies of genes, and correlation with clinical pregnancy of IVF were analyzed. The AMH 146 T > G G/G genotype in women was associated with a lower clinical pregnancy rate (T/T: 55.0%, T/G: 51.8%, G/G: 40.0%; p < 0.05). Women with the AMH 146 T > G GG genotype were half as likely to have a clinical pregnancy compared with women with TT genotypes (OR = 0.55, 95% CI: 0.34⁻0.88, p = 0.014). With multivariate analysis, the AMH 146 T > G GG genotype remains as a significant independent factor to predict clinical pregnancy (p = 0.014). No significant difference was found between AMHRII polymorphisms and clinical pregnancy outcomes of IVF. In conclusion, our results show that AMH 146 T > G seems to be a susceptibility biomarker capable of predicting IVF pregnancy outcomes. Further studies should focus on the mechanism of these associations and the inclusion of other ethnic populations to confirm the findings of this study.

Effects of reactive oxygen species levels in prepared culture media on embryo development: a comparison of two media.

OBJECTIVE: This study determined the correlation between the levels of reactive oxygen species (ROS) in prepared culture media and the early development of human embryos. MATERIALS AND METHODS: This was an autocontrolled comparison study. A total of 159 patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment were recruited in this study. The pH values, osmolarity pressures, and ROS levels of 15 batches of two culture media were measured. Sibling oocytes or embryos from individual patients were randomly assigned to two culture groups with Quinn's Advantage Cleavage and Blastocyst media (QAC/QAB) or GIII series cleavage and blastocyst media (G1.3/G2.3). The difference between the two culture groups was analyzed using one-sample t test. RESULTS: The QAC/QAB and G1.3/G2.3 media exhibited similar pH values and osmolarity pressures. However, the prepared QAC/QAB media were characterized to contain lower amounts of ROS than the G1.3/G2.3 media. Furthermore, the blastocysts that developed under the QAC/QAB media were morphologically superior to those that developed under the G1.3/G2.3 media. CONCLUSION: The elevated ROS levels in culture media were associated with poor development of blastocyst-stage embryos. Measurement of ROS levels may be a valuable process for medium selection or modification.

Nitric oxide modulates mitochondrial activity and apoptosis through protein S-nitrosylation for preimplantation embryo development.

PURPOSE: Previous studies reported that patients with endometriosis had excess nitric oxide (NO) in the reproductive tract and poor embryo development in IVF cycles. This study aims to elucidate the effects of NO on early embryo development. METHODS: Zygotes from superovulated B6CBF1 mice were cultured to blastocysts in a variety of media. Sodium nitroprusside (SNP) and N(G)-nitro-L-arginine (LNA) were added to the culture medium as a NO donor and a NO synthase inhibitor, respectively. The localization and fluorescence intensity of S-nitrosylated (SNO) proteins within 2-cell stage embryos were analyzed with confocal microscopy. Apoptosis and ATP production in the blastocysts were measured. RESULT(S): Subsequent to NO exposure, the SNO proteins mainly colocalized with the mitochondria and endoplasmic reticulum and the intensity of SNO proteins increased. The addition of a quanylate cyclase inhibitor and a cyclic GMP mimic agent induced nonsignificant changes in SNO proteins, whereas addition of a superoxide scavenger or a reduced form of glutathione rescued the embryos from the effects of NO. However, superoxide scavenger supplementation resulted in decreased blastocyst ATP production. CONCLUSION(S): Elevated NO exerts deleterious effects on embryo development, possibly through protein S-nitrosylation in the mitochondria and endoplasmic reticulum. Including glutathione as a component in the culture medium might counteract this effect.

The association between microenvironmental reactive oxygen species and embryo development in assisted reproduction technology cycles.

This study was designed to determine the relevance between the levels of reactive oxygen species (ROS) in microenvironment (follicular fluid or culture media) and the embryo development in IVF/ICSI cycles. A total of 466 follicles from 174 IVF/ICSI cycles were collected for this study. The ROS levels in monofollicular fluid and spent culture media were evaluated by chemiluminescence assay with luminol as a probe. The results demonstrated that it is in ICSI cycles that elevated ROS levels in follicular fluid were associated with day 3 poor embryo quality. The ROS levels in spent culture media were correlated with advanced degree of fragmentation. In addition, ROS levels in culture media, instead of in follicular fluid, were negatively correlated with implantation potential of embryos. The ROS levels in culture media may be viewed as an embryo metabolic marker and function as an adjuvant criterion for embryo selection.

Magnetic-activated cell sorting for sperm preparation reduces spermatozoa with apoptotic markers and improves the acrosome reaction in couples with unexplained infertility.

BACKGROUND: Couples with unexplained infertility (UI) tend to have low fertilization rates with current IVF procedures. Here, we attempted to identify spermatozoa with apoptotic markers in couples with UI and unsuccessful intrauterine insemination (IUI) and we investigated the efficiency and benefit of magnetic-activated cell sorting (MACS) for sperm preparation in such patients. METHODS: Sixty couples with UI and two IUI failures were recruited. The sperm were prepared by conventional density gradient centrifugation (DGC) and divided into two aliquots. One aliquot was used as a control and the other was further processed by MACS (D + M). Apoptotic markers were identified using fluorescence-labeled dye and flow cytometry, including externalization of phosphatidylserine (EPS), disrupted mitochondrial membrane potential (MMP) and DNA fragmentation. The fertilization potential of prepared spermatozoa was analyzed by basic semen analysis, computer-aided sperm analysis and the induced acrosome reaction test (IART). RESULTS: After DGC, spermatozoa showed 18.6% EPS, 28.3% disrupted MMP and 13.5% DNA fragmentation. Numbers of spermatozoa with apoptotic markers were significantly reduced by D + M, versus DGC alone (P < 0.001). Although the motility of spermatozoa was slightly decreased after MACS, most sperm motion characteristics were not impaired. Interestingly, the IART significantly improved after D + M, versus DGC alone, especially for the couples with a normal hemizona assay (P < 0.001). CONCLUSIONS: The spermatozoa prepared by D + M showed a reduced level of apoptotic markers. Improvement in the IART suggests a high fertilization potential of the processed spermatozoa. The identification of apoptotic markers and use of MACS may be helpful in directing the management plan for patients with UI and multiple IUI failures.

Prostacyclin enhances mouse embryo development and hatching but not increased embryonic cell number and volume.

OBJECTIVE: To evaluate in vitro effects of prostacyclin (PGI2), we cultured mouse embryos with a PGI2 analogue, because human fallopian tube cells synthesize abundant amounts of PGI2. DESIGN: Animal model. SETTING: Animal study in a private infertility clinic. ANIMAL(S): Mouse embryos. INTERVENTION(S): In vitro effects of PGI2 analogue on mouse embryos. MAIN OUTCOME MEASURE(S): Development rate, blastocyst volume, rate of complete hatching, and cell number of hatched blastocysts. RESULT(S): Exposure to PGI2 analogue during the four-cell to morula stages was critical to enhanced embryo development and hatching but did not increase blastocyst volume or cell number of hatched blastocysts. The effects of PGI2 analogue were statistically significant at 1.0 micromol/L and 2.0 micromol/L in human tubal fluid medium, with or without 1% bovine serum albumin. CONCLUSION(S): Prostacyclin analogue enhanced embryo development and hatching, but PGI2 did not increase number of cells in hatched blastocysts or blastocyst volume.

Sperm DNA fragmentation negatively correlates with velocity and fertilization rates but might not affect pregnancy rates.

OBJECTIVE: To evaluate sperm DNA fragmentation in correlation with sperm parameters and IVF/intracytoplasmic sperm injection (ICSI) outcomes. DESIGN: Retrospective review. SETTING: A tertiary infertility referral clinic. PATIENT(S): We collected 303 semen samples from patients undergoing IVF with or without ICSI. INTERVENTION(S): Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay, measurement of fertilization rates, good embryo rates, and pregnancy rates for the IVF/ICSI program. MAIN OUTCOME MEASURE(S): The percentage of sperm with DNA fragmentation, correlated with semen analysis parameters and IVF/ICSI outcomes. RESULT(S): Sperm DNA fragmentation rates were significantly higher in patients with abnormal sperm parameters than in those with normal sperm parameters. When sperm DNA fragmentation was >10%, fertilization rates were affected. Sperm DNA fragmentation rates were negatively correlated with sperm velocity parameters but did not affect pregnancy outcomes. CONCLUSION(S): The results indicated that sperm DNA fragmentation affects fertilization rates and sperm motility but might not affect pregnancy rates.

DNA fragmentation, mitochondrial dysfunction and chromosomal aneuploidy in the spermatozoa of oligoasthenoteratozoospermic males.

PURPOSE: This study determined the incidence of sperm nuclear DNA fragmentation, mitochondrial dysfunction, and chromosomal aneuploidy. The results were correlated with the semen analysis parameters and fertilization rates. METHODS: Semen samples from 10 men showing oligoasthenoteratozoospermia (OAT) and undergoing ICSI treatment were analyzed. Another semen samples from 10 men showing normozoospermia and undergoing IVF treatment were analyzed for comparison. The samples were prepared using a two-step discontinuous Percoll gradient (80%-50%) and analyzed using a Hamilton-Thorne Integrated Visual Optical System (IVOS) Sperm Analyzer. DNA fragmentation was detected with a terminal deoxynucleotidyl transferase-mediated dUTP nick end label (TUNEL) assay. Functional integrity of mitochondria was detected using an Apoalert Mitochondrial Membrane Sensor Kit. Chromosomal aneuploidy was assayed by fluorescence in situ hybridization. RESULTS: Higher sperm DNA fragmentation rate (18.8% vs. 2.8%), mitochondrial dysfunction rate (24.9% vs. 5.7%), and chromosomal aneuploidy rate (0.12% vs. 0.06%) were found in the oligoasthenoteratozoospermic patients in comparison with the normozoospermic patients. CONCLUSIONS: The result indicates that spermatozoa from oligoasthenoteratozoospermic patients contain greater DNA fragmentation, mitochondrial dysfunction, and chromosomal aneuploidy. Because extremely poor semen samples are the indication for ICSI treatment, the result indicates the importance of selecting good quality sperm for oocyte injection.