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Andrology Jan 2024Infertility affects 186 million people worldwide, with male factors contributing to 50% of infertility cases. Semen analysis is a key for diagnosing male factor... (Review)
Review
BACKGROUND
Infertility affects 186 million people worldwide, with male factors contributing to 50% of infertility cases. Semen analysis is a key for diagnosing male factor infertility, but sperm parameters can be influenced by ejaculatory abstinence (EA) duration. Shortening or prolonging EA can impact on semen quality and assisted reproductive technology (ART) outcomes, but the optimal EA duration remains unclear, particularly for infertility patients.
OBJECTIVES
This study conducts a comprehensive meta-analysis to explore the impact of varying abstinence durations on semen quality and fertility outcomes.
METHODS
Three English database (PubMed, Embase, and Cochrane Central Register of Controlled Trials) as well as four Chinese database (China National Knowledge Infrastructure, Chinese Scientific Journals database, WanFang database, and Chinese Biomedical Literature database) were searched from 2000 to August 2023. The classical meta-analysis and "one-stage" dose-response meta-analysis were conducted to compare the associations of different abstinence durations (short-term abstinence vs. long-term abstinence) on semen quality in healthy adult and different type of infertile patients.
RESULTS
There were 85 eligible studies were finally included. The meta-analysis of volume (mean difference [MD] = -0.95 mL, 95% confidence interval [CI]: -1.16 to -0.74 mL), total sperm count (TSC) (MD = -102.45×10 , 95% CI: -117.98×10 to -86.91×10 ), sperm concentration (SC) (MD = -11.88×10 /mL, 95% CI: -18.96×10 /mL to -4.80×10 /mL), DNA fragmentation index (DFI) (MD = -2.37%, 95% CI: -4.73% to -0.01%) in healthy men showed a significant decrease with different abstinence durations (short-term abstinence vs. long-term abstinence). The meta-analysis of infertile men showed significant decrease in volume in various subgroups (MD range: -0.73 to -1.17 mL) with P < 0.01; TSC (MD = -61.93×10 , 95% CI: -88.84×10 to -35.01×10 ), SC (MD = -5.39×10 /mL, 95% CI: -9.97×10 to -0.81×10 /mL), DFI (MD = -5.63%, 95% CI: -10.19% to -1.06%) in unexplained infertility subgroup; significant increase in viability (MD = 6.14%, 95% CI: 3.61% to 8.68%) in the unexplained infertility subgroup. The dose-response meta-analysis showed that TSC in oligozoospermia showed a nonlinear increase (coefficient from 3.38 to -5.76, P from 0.02 to 0.22) and the truncation point was around the 4th to 5th abstinence day. The percentage of progressive motile sperm (PR) in asthenozoospermia showed a significant decrease (coefficient = -2.39, 95% CI: -4.28 to -0.50). For fertility outcomes of different ARTs, only the clinical pregnancy rate (CPR) in the intrauterine insemination (IUI) subgroup showed a significant decrease around the 3rd day (coefficient = 0.85, 95% CI: 0.75 to 0.97).
CONCLUSIONS
Short-term abstinence may be associated with limited improvements in semen quality in healthy men but could be more beneficial for infertile men, especially within the first 4 days of abstinence. Caution is urged in making definitive conclusions about the causal relationship between abstinence time and semen quality changes due to potential confounding and interactions.
PubMed: 38197853
DOI: 10.1111/andr.13583 -
Andrology Feb 2024Telomeres are essential for the integrity of chromosome ends during cell division and their involvement in different processes linked to aging has been established.... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Telomeres are essential for the integrity of chromosome ends during cell division and their involvement in different processes linked to aging has been established. These chromosome components are involved in spermatogenesis and seem to play an important role in fertilization and embryo development. Telomere length is shortened with each cell division. Recently, short sperm telomere length has been proposed as a potential biomarker of male infertility.
OBJECTIVES
To conduct a systematic review and meta-analysis of studies exploring the association between spermatozoa and/or leukocyte telomere length with sperm quality parameters and different infertility conditions.
MATERIAL AND METHODS
A systematic review and meta-analysis was conducted with studies from Medline-PUBMED and Cochrane Library databases until May 2022. Eligible studies included cohort, cross-sectional and case-control studies, and telomere length in spermatozoa and/or leukocytes cells was defined as the exposure. Semen quality parameters or infertility conditions (e.g., oligozoospermia, asthenozoospermia, teratozoospermia, or other spermatogenic impairment combinations) were defined as the outcomes.
RESULTS
Twenty-three observational studies were included. In the qualitative analysis, high heterogeneity was observed between studies regarding the associations between telomere length and semen parameters in different normozoospermic/fertile and oligozoospermic/infertile populations. In the meta-analysis, spermatozoa and leukocyte telomere length were shorter in infertile individuals than in fertile individuals (mean difference [95% confidence interval]: -1.43 [-1.66 to -1.21], p-value <0.001 and -1.67 [-2.02 to -1.31], p-value <0.001, respectively). Moreover, in terms of sperm telomere length, these differences were also significant between individuals with a normal seminogram and individuals with a low quantity of spermatozoa in the ejaculate (-0.97 [-1.32, -0.61], p-value <0.001).
CONCLUSION
The current systematic review and meta-analysis suggests the potential role of spermatozoa or leukocyte telomere length as a reliable biomarker of semen quality, which may help distinguish between infertility conditions beyond the routine semen analysis.
Topics: Humans; Male; Semen Analysis; Semen; Cross-Sectional Studies; Spermatozoa; Infertility, Male; Telomere; Biomarkers
PubMed: 37328426
DOI: 10.1111/andr.13482 -
JBRA Assisted Reproduction Jun 2024Infertility is a widespread global issue that affects approximately 15% of sexually active and active couples, which contributes to about 50% of cases. Currently, the... (Review)
Review
Infertility is a widespread global issue that affects approximately 15% of sexually active and active couples, which contributes to about 50% of cases. Currently, the condition remains prevalent and often inadequately treated. This systematic review aims to evaluate existing studies investigating the effects of probiotic supplementation in men. A comprehensive search was conducted across major databases, including PubMed, Cochrane, Science Direct, and Scielo, using relevant keywords such as 'probiotic' OR 'Lactobacillus' OR 'Bifidobacterium' AND 'Male infertility' OR 'male fertility' OR 'sperm quality' OR 'sperm motility' OR 'oligoasthenoteratozoospermia' and their Portuguese equivalents. Four randomized clinical studies met the inclusion criteria, focusing on men diagnosed with idiopathic male infertility (oligozoospermia, teratozoospermia, and asthenozoospermia). The findings revealed that probiotic administration exhibited promising antioxidant properties by combating reactive oxygen species (ROS), consequently protecting sperm DNA from damage that correlates with declining sperm quality. Significant improvements were observed across all sperm parameters, with notable enhancement in motility. Consequently, probiotic supplementation emerges as a potential therapeutic alternative for men diagnosed with idiopathic infertility, demonstrating positive effects on sperm quality.
Topics: Humans; Male; Probiotics; Infertility, Male; Dietary Supplements; Sperm Motility
PubMed: 38530761
DOI: 10.5935/1518-0557.20240013 -
The World Journal of Men's Health Jan 2024The advent of proteomics provides new opportunities to investigate the molecular mechanisms underlying male infertility. The selection of relevant targets based on a...
PURPOSE
The advent of proteomics provides new opportunities to investigate the molecular mechanisms underlying male infertility. The selection of relevant targets based on a single analysis is not always feasible, due to the growing number of proteomic studies with conflicting results. Thus, this study aimed to systematically review investigations comparing the sperm proteome of normozoospermic and infertile men to define a panel of proteins with the potential to be used to evaluate sperm quality.
MATERIALS AND METHODS
A literature search was conducted on PubMed, Web of Science, and Scopus databases following the PRISMA guidelines. To identify proteins systematically reported, first the studies were divided by condition into four groups (asthenozoospermia, low motility, unexplained infertility, and infertility related to risk factors) and then, all studies were analysed simultaneously (poor sperm quality). To gain molecular insights regarding identified proteins, additional searches were performed within the Human Protein Atlas, Mouse Genome Informatics, UniProt, and PubMed databases.
RESULTS
Thirty-two studies were included and divided into 4 sub-analysis groups. A total of 2752 proteins were collected, of which 38, 1, 3 and 2 were indicated as potential markers for asthenozoospermia, low motility, unexplained infertility and infertility related to risk factors, respectively, and 58 for poor sperm quality. Among the identified proteins, ACR, ACRBP, ACRV1, ACTL9, AKAP4, ATG3, CCT2, CFAP276, CFAP52, FAM209A, GGH, HPRT1, LYZL4, PRDX6, PRSS37, REEP6, ROPN1B, SPACA3, SOD1, SPEM1, SPESP1, SPINK2, TEKT5, and ZPBP were highlighted due to their roles in male reproductive tissues, association with infertility phenotypes or participation in specific biological functions in spermatozoa.
CONCLUSIONS
Sperm proteomics allows the identification of protein markers with the potential to overcome limitations in male infertility diagnosis and to understand changes in sperm function at the molecular level. This study provides a reliable list of systematically reported proteins that could be potential targets for further basic and clinical studies.
PubMed: 37118964
DOI: 10.5534/wjmh.220262