The influence of paternal overweight on sperm chromatin integrity, fertilization rate and pregnancy outcome among males attending fertility clinic for IVF/ICSI treatment

Effect of paternal body mass index on maternal and child-health outcomes of singletons after frozen-thawed embryo transfer cycles: a retrospective study

The objective was to analyze the effect of paternal body mass index (BMI) on maternal and child-health outcomes of singletons after frozen-thawed embryo transfer (FET) cycles. A retrospective cohort study was conducted between January 2019 and December 2021. Pregnancy, perinatal complications and neonatal outcomes were compared among different paternal BMI. Multivariate logistic regression was performed to evaluate the relationship between different paternal BMI and pregnancy, obstetric and neonatal outcomes. The paternal normal group was more likely to suffer from gestational hypertension than the paternal obesity group (3.59% vs. 2.42%), and paternal underweight group was more likely to suffer from preeclampsia than the other three groups (11.63% vs. 4.43%, 7.57%, 4.03%). Birthweight among infants in the paternal overweight categories was significantly higher than infants in the paternal normal weight categories. The rate of foetal macrosomia was higher among infants in the paternal overweight (12.36%) category, while lower among infants in the paternal underweight categories (2.33%). The incidence of macrosomia in the paternal overweight categories (aOR 1.527, 95% CI 1.078-2.163) was significantly higher than those normal controls after adjustment for known confounding factors. The rates of LGA babies were higher in the paternal overweight category (aOR 1.260, 95% CI 1.001-1.587) compared with those in the paternal normal weight category, before and after adjustment. The results suggest that parental pre-pregnancy overweight or obesity has an adverse effect on the perinatal complications and neonatal outcomes.

Impact of metabolic syndrome factors on sperm DNA fragmentation in males from infertile couples: A systematic review and meta-analysis

PURPOSE

To investigate the impact of metabolic syndrome factors on sperm DNA fragmentation (sDF) in males from infertile couples.

METHODS

A systematic literature search was performed across ten databases for literature published from January 1, 2013 until September 13, 2023. The protocol has been registered on PROSPERO (CRD42023458359), and the literature search strategy is adhered to the PRISMA framework. Studies that evaluated sDF, as indicated by DNA fragmentation index (%DFI), in males from infertile couples in relation to metabolic syndrome factors were included. Meta-analysis, using random effects model and Bayesian framework network, was performed, and data were presented as Standardized Mean Differences (SMD) with corresponding 95 % Confidence Interval (CI).

RESULTS

Of the 2579 citations identified, eleven studies were included in this meta-analysis. The findings revealed that the %DFI was not associated with overall metabolic syndrome factors (p-tot = 0.235; SMD = 0.57 [95 %CI: -0.37, 1.52]), metabolic syndrome status (p-tot = 0.337; SMD = 0.08 [95 %CI: -0.08, 0.24), increased body mass index (p-tot = 0.237; SMD = 0.71 [95 %CI: -0.47, 1.89]), or glycaemic profile (p-tot = 0.93; SMD = 0.13 [95 %CI: -2.72, 2.98]). High levels of heterogeneity were observed (p < 0.01) in all subgroups, except for metabolic syndrome status.

CONCLUSION

The association between metabolic syndrome factors and sDF is conflicting. However, interpreting the association requires caution, as confounding factors, indicated by high heterogeneity, may conceal the outcome. Metabolic syndrome may influence other factors contributing to male infertility, highlighting the importance of promoting a healthy lifestyle.

Effect of body mass index on semen quality, sperm chromatin integrity and sperm DNA methylation

Obesity represents a growing problem due to its impacts on human health and reproduction. In this study, we analysed semen quality, sperm DNA integrity and gene-specific CpG methylation in 116 healthy men from normal population. The men were divided into three groups according to their body mass index (BMI), and their ejaculates were analysed using standard methods, sperm chromatin structure assay (SCSA), methylation next generation sequencing (NGS) and amplicon sequencing. The sperm methylation NGS revealed six significantly differentially methylated regions (DMRs). Using subsequent targeted amplicon sequencing in 116 men, two of the DMRs were proved as differentially methylated in sperm of men with normal BMI vs. BMI ≥ 25. The DMRs were located in the EPHA8 and ANKRD11 gene. Also, we detected a significant decline in the EPHA8, ANKRD11 and CFAP46 gene methylation in association with increasing BMI values. The genes EPHA8 and ANKRD11 are involved in the nervous system and brain development; the CFAP46 gene plays a role in a flagellar assembly and is associated with sperm motility. Significantly lower rates of motile and progressive motile sperm were observed in men with BMI ≥ 30. Our results show that excess body weight can modify CpG methylation of specific genes, affect sperm motility, and compromise sperm chromatin integrity. These factors can stand behind the observed reduced fertility in men with obesity. The methylation changes might be transmitted to their offspring through sperm, and become a basis for possible developmental and reproductive issues in the next generation.

Effect of paternal overweight or obesity on semen parameters, clinical pregnancy and live birth outcomes in men treated with intrauterine insemination (IUI)

Background

Overweight and obese individuals are steadily increasing in recent years. Male overweight or obesity has adverse impact on reproductive functions. The study aimed to evaluate the potential impact of paternal overweight or obesity on sperm quality and clinical pregnancy outcome in patients undergoing intrauterine insemination (IUI) treatment.

Methods

This retrospective study included 1,036 couples from our reproductive center between July 2019 and August 2022. All males were categorized into normal weight, overweight, or obese groups according to their body mass index (BMI). Baseline characteristics and reproductive hormones were analyzed. Semen parameters, clinical pregnancy and live birth outcomes were compared among the different BMI groups.

Results

There were no significant differences in sperm concentration, total sperm motility, progressive sperm motility, normal sperm morphology and sperm DNA fragmentation index (DFI) among the three groups. However, the obese group exhibited a significantly decreased semen volume compared to the other two groups (P<0.01). No differences were found in clinical pregnancy rate (CPR), abortion rate (AR) and live birth rate (LBR) among the groups (P>0.05). Slight higher ARs were observed in overweight and obese groups compared to normal group (13.64%, 21.05% vs. 11.11%, P=0.49).

Conclusions

These data suggest that male obesity leads to a significant decrease in semen volume. It is thus recommended that male BMI should be regarded as one of the predictors for IUI treatment to avoid a decrease in semen volume.

Sperm chromatin: Evaluation, epigenetic signatures and relevance for embryo development and assisted reproductive technology outcomes

Sperm chromatin is distinct from somatic cell chromatin, as a result of extensive remodeling during the final stages of spermatogenesis. In this process, the majority of histones is replaced with protamines. The chromatin is consequently highly condensed and inert, which facilitates protection of the DNA. The sperm epigenomic landscape is shaped by histone retention, histone and protamine modification, DNA methylation, and RNAs. In recent years, sperm chromatin integrity and its epigenetic marks have been increasingly studied, and the constitution of sperm chromatin is steadily being uncovered. This growing body of research prompts assessment of the frequently overlooked involvement of sperm in fertility and embryonic development. Moreover, numerous endogenous and exogenous factors are known to affect sperm chromatin, which may in turn impact the reproductive success. Concerns have been raised about the effects of assisted reproductive technology (ART) on the sperm epigenome, embryonic development and offspring health. This review examines the structure and epigenetic signatures of sperm chromatin in the context of fertility and early embryonic development. Additionally, sperm chromatin evaluation and causes of aberrant integrity are outlined. Building on the knowledge discussed in the current review, future research should aim to elucidate the intricate relationship between all aspects of sperm chromatin and embryo development. This could lead to the uncovering of new targets for treating infertility, as well as the acquisition of much needed insights into the possible reciprocal association between ART and sperm chromatin integrity.

Influence of male body mass index on semen analysis parameters and in vitro fertilization outcomes

Concurrent global increase of prevalence of obesity and male fertility implies link between overweight and obesity with male subfertility. This hypothesis is supported by numerous population-based epidemiological studies. Increase in body mass index (BMI) is associated with poor sperm quality in fertile, and more noticeable in infertile men. Nevertheless, some studies disprove damaging effect of BMI on semen quality. To examine the influence of men's BMI in infertile couples undergoing in vitro fertilization (IVF) on semen analysis parameters and IVF outcomes. Study encompassed all couples who underwent IVF at Gynecology and Obstetrics Clinic Narodni Front in Belgrade during 2018 and 2019. Exclusion criteria were azoospermia, conditions and diseases that could affect the semen analysis parameters (diabetes, malignant diseases treated with radiation and/or chemotherapy, trauma or surgery of the genital organs, mumps or undescended testicles in childhood). Evaluated semen analysis parameters included semen ejaculate volume, sperm pH, sperm count, sperm motility, and sperm morphology. IVF outcomes comprised total number of embryos, number and percentage of obtained good-quality embryos and clinical pregnancy rates. Based on BMI value, participants were divided into a group of underweight (Group 1), normally weight (Group 2), overweight (Group 3), and obese men (Group 4). After applying inclusion and exclusion criteria, 411 men (couples) were included in the analysis. The largest number of men were overweight, while the smallest belonged to the group of underweight participants. There are no significant differences in the semen analysis parameters between study groups. Correlation analysis shown weak and insignificant correlation between BMI and semen analysis parameters. The number and proportion of good quality embryos is significantly lower in overweight and obese study groups compared to normal weight and underweight groups (2.89, 2.91, 2.42, and 2.36, respectively, P = .041). The differences in other IVF outcomes: total number of embryos (3.61, 3.74, 3.21, and 3.37, respectively) and clinical pregnancy rates (41.26%, 43.09%, 42.78%, and 39.95%, respectively) between study groups were not significant (P > .05). BMI does not significantly affect semen analysis parameters, but a higher BMI is associated with a lower number and proportion of good quality embryos in IVF outcomes.

Dulaglutide rescues the elevated testicular dysfunction in a mouse model of high-fat diet-induced obesity

Obesity is a well-known risk factor for testicular function; however, dulaglutide's effect on the testis in obesity has received little attention. Currently, clinicians prescribe the antidiabetic drug dulaglutide only off-label for weight management in non-diabetics. Investigating the impact of this novel compound on obesity is critical for determining whether it has any disruptive effects on testicular cells. We used a well-known animal model of high-fat diet-induced obesity in this investigation, and testicular dysfunction was determined by sperm DNA damage, spermatocyte chromosomal abnormalities, and spermiogram analysis. Following a 12-week high-fat diet challenge, mice were randomly assigned to dulaglutide (0.6 mg/kg/day) or saline treatments for five weeks. Testes and sperm cells were collected 24 h after the last dulaglutide injection. Untreated obese mice had a lower testes/body weight ratio, more sperm DNA damage, diakinesis-metaphase I chromosomal abnormalities, a lower sperm count/motility, more cell morphological defects, and an altered testicular redox balance. In obese mice, dulaglutide injection efficiently restored all disturbed parameters to their control levels. Dulaglutide injection into healthy mice exhibited no significant harmful effects at the applied regimen. As a result, we infer that dulaglutide therapy might bring obese men additional benefits by recovering testicular dysfunction induced by obesity.

Effect of Paternal Body Mass Index on In Vitro Fertilization and Neonatal Outcomes among Oligozoospermia and Asthenospermia Patients

PURPOSE

Male overweight and obesity could affect sperm quality and reproductive health. However, the impact of body mass index (BMI) on assisted reproductive technology (ART) outcomes in oligospermia and/or asthenospermia patients is yet lacking. This study aims to assess the impact of paternal BMI on ART and neonatal outcomes among oligozoospermia and/or asthenospermia patients undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

MATERIALS AND METHODS

In this study, 2,075 couples undergoing their first fresh embryo transfer between January 2015 and June 2022 were recruited. Following the World Health Organization's (WHO's) categories, couples were stratified into three cohorts based on paternal BMI: normal weight (18.5-24.9 kg/m²), overweight (25.0-29.9 kg/m²), and obese (≥30.0 kg/m²). Modified Poisson regression models were used to assess the associations of paternal BMI with fertilization, in vitro embryonic development, and pregnancy outcomes. Logistic regression models were performed to investigate the associations of paternal BMI with pregnancy loss and neonatal outcomes. Furthermore, stratified analyses were performed based on fertilization methods, male infertility cause, and maternal BMI.

RESULTS

Higher paternal BMI is associated with a lower likelihood of achieving normal fertilized (p-trend=0.002), Day 3 transferable (p-trend=0.007), and high-quality embryos (p-trend=0.046) in IVF cycles, rather than in ICSI cycles. Paternal BMI of oligospermia or asthenospermia was negatively correlated with day 3 transferable (p-trend=0.013 and 0.030) and high-quality embryos (p-trend=0.024 and 0.027). Moreover, for neonatal outcomes, paternal BMI was positively associated with macrosomia (p-trend=0.019), large for gestational age (LGA) (p-trend=0.031), and very LGA (p-trend=0.045).

CONCLUSIONS

Our data suggested that higher paternal BMI was associated with fetal overgrowth, reduced fertilization, and embryonic development potential. Among males with oligospermia and/or asthenospermia, the impact of overweight and obesity on the choice of fertilization method and the long-term effects on their offspring need to be further investigated.

Outcomes comparison of testicular versus ejaculated sperm for intracytoplasmic sperm injection in infertile men with high DNA fragmentation: updated systematic review and meta-analysis

Background

The testicular sperm instead of ejaculated sperm for intracytoplasmic sperm injection (ICSI) in infertile men with high sperm DNA fragmentation (SDF) is a controversial topic. This updated systematic review and meta-analysis aims to evaluate whether couples with high level of SDF will benefit more from intracytoplasmic sperm injection with testicular sperm (Testi-ICSI) as compared to intracytoplasmic sperm injection with ejaculated sperm (Ejac-ICSI).

Methods

A systematic search was conducted according to PRISMA guidelines, using PubMed, Embase, Web of Science and the Cochrane Central Register of Controlled Trials (CENTRAL), encompassing studies from the earliest record until May 2022. We included studies analyzing comparative pregnancy outcomes of testicular versus ejaculated sperm for ICSI in infertile men with high DNA fragmentation. The risks of bias and certainty of evidence were assessed using the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework, respectively.

Results

Eleven studies were included. Meta-analysis showed that SDF levels revealed a significant difference association [odds ratio (OR) =-25.81; 95% confidence interval (CI): -34.82, -16.81; I2=94%; P<0.00001] between testicular and ejaculated sperm. Compared with Ejac-ICSI, a non-significant tendency was observed for fertilization rates (FRs) in the Testi-ICSI group (OR =0.87; 95% CI: 0.67, 1.12; I2=81%; P=0.28). However, there was significant difference pointing to better outcomes for Testi-ICSI in clinical pregnancy rates (CPRs) (OR =2.36; 95% CI: 1.71, 3.24; I2=0%; P<0.00001), live birth rates (LBRs) (OR =3.10; 95% CI: 2.13, 4.51; I2=4%; P<0.00001) and miscarriage rates (MRs) (OR =0.28; 95% CI: 0.13, 0.60; I2=0%; P=0.001).

Conclusions

Results of this updated meta-analysis reveal that SDF rates are lower in testicular sperm than in ejaculated sperm and that Testi-ICSI is correlated with better clinical outcomes, including higher CPRs, higher LBRs, and lower MRs in infertile males with high SDF levels. Nevertheless, with the overall low to moderate quality of the studies, further well-designed controlled studies are required.

Effects of fasting hyperglycemia in men on pregnancy outcomes of singleton pregnant women with cryo-thawed embryo transfer

BACKGROUND

The relationship of metabolic issues to pregnancy outcomes during assisted reproductive technology (ART) is gaining much attention. Fasting Plasma Glucose (FPG) is one of the most common metabolic indicators. Abnormal FPG not only affects the quality of life of human body, but also has a bearing on reproductive health. However, most attentions are paid on women's physical health and reproductive assessment, the health status of the male partner on pregnancy outcomes during ART treatment is often neglected. This study investigated whether male fasting hyperglycemia (FH, FPG > 6.1 mmol/L) can affect live birth rates (LBR) in singleton intrauterine clinical pregnancy women with cryo-thawed embryo transfer (CET) cycles.

MATERIAL AND METHODS

A retrospective cohort study (370 CET cycles with first singleton clinical intrauterine pregnancy and grouped by male FPG) was conducted to analyze the relationship between male FH and clinical pregnancy outcomes using binary logistic regression; the odds ratios (ORs) and 95% confidence intervals (CIs) were calculated as a measure of relevancy. Live birth rate was the main outcome measure.

RESULTS

The live birth rate (LBR) was significantly lower [58.6% vs. 81.8%, P = 0.007, adjusted OR 0.635, 95% CI 0.456-0.884] and miscarriage rate (MR) was significantly higher [41.4% vs. 18.2%, P = 0.007, adjusted OR 1.575, 95% CI 1.131-2.195] in the FH group when compared with the Con group. There was no difference in healthy baby rate [88.2% vs. 89.6%, P = 0.058, adjusted OR 2.143, 95% CI 0.974-4.716] or abnormal birth weight rate (23.5% vs. 11.8%, P = 0.238, adjusted OR 2.859, 95% CI 0.777-10.460] between the FH and control group. No birth defects were observed in the present study.

CONCLUSION

Male FH is an independent risk factor for lower LBR and higher MR in singleton intrauterine pregnancy women with CET cycles.

Association of diet and lifestyle factors with semen quality in male partners of Chinese couples preparing for pregnancy

BACKGROUND

Semen quality significantly influences conception, and its preservation is crucial for couples seeking pregnancy. We investigated dietary and lifestyle risk factors impacting semen quality.

METHODS

A total of 466 males from the Guangzhou Women and Children's Medical Center's pre-pregnancy consultation clinic were recruited between January 2021 and March 2023 for inclusion. Semen analysis was performed, and diet and lifestyle data were gathered via questionnaire. Logistic regression was utilized to examine the link between diet, lifestyle variables, and semen quality.

RESULTS

Smoking worsened progressive sperm motility (38.0% vs. 36.0%, t = 2.262; P = 0.049). Alcohol consumption impaired progressive motility (40.5 ± 17.8% vs. 34.7 ± 16.1%, t = 3.396; P < 0.001) and total motility (56.0% vs. 64.0%; P = 0.001). Using plastic beverage bottles for oil or seasonings lowered sperm concentrations (40.4% vs. 59.0% vs. 65.5%; P = 0.032). A sweet diet correlated with higher total sperm motility (55.0% vs. 60.0%, 62.0% vs. 63.2%; P = 0.017). Higher milk product intake improved sperm concentration (41.6106 vs. 63.7106 vs. 66.1*106; P = 0.021) and motility (54.5% vs. 56.0% vs. 63.0%; P = 0.033). More frequent egg consumption increased semen volume (3.1 mL vs. 3.8 mL vs. 4.0 mL; P = 0.038). Roughage intake enhanced sperm concentration (160.8106 vs. 224.6106; P = 0.027), and adequate sleep improved progressive sperm motility rate (35.4% ± 18.2% vs. 40.2 ± 16.3%, F = 3.747; P = 0.024) and total motility (52.7% vs. 61.5%; P = 0.013). The regression model showed that using plastic containers for condiments was a protective factor for semen volume (OR: 0.12; CI 0.03-0.55; P = 0.006), sperm concentration (OR: 0.001, CI 0.00-0.30; P = 0.012), and count (OR: 0.12, CI 0.03-0.48; P = 0.003). Milk and egg consumption were also protective for semen volume (OR: 0.18, CI 0.06-0.51; P = 0.001 and OR: 0.11, CI 0.03-0.55; P = 0.006, respectively), while sufficient sleep benefitted total sperm motility (OR: 0.47, CI 0.24-0.95; P = 0.034).

CONCLUSIONS

Smoking and drinking, type of condiment container, diet preference, sleep duration, and milk, roughage, and egg consumption may reduce semen quality.

Sperm DNA damage: The possible link between obesity and male infertility, an update of the current literature

Obesity prevalence worldwide is increasing significantly. Whilst maternal obesity has clear detrimental impacts on fertility, pregnancy and foetal outcomes, more recently there has been an increasing focus on the role of paternal obesity in human fertility. Recent meta-analyses have indicated that obesity in men negatively affects basic sperm parameters such as sperm count, concentration and motility, increases the incidence of infertility and reduces the chances of conception. Sperm DNA damage, typically characterised by DNA strand breaks and oxidation of DNA nucleotides, is a specialised marker of sperm quality that has been independently associated with recurrent miscarriage, reduced assisted reproduction success and increased mutational loads in subsequent offspring. Whilst, there are still conflicting data in humans as to the association of obesity in men with sperm DNA damage, evidence from rodent models is clear, indicating that male obesity increases sperm DNA damage. Human data are often conflicting because of the large heterogeneity amongst studies, the use of body mass index as the indicator of obesity and the methods used for detection of sperm DNA damage. Furthermore, comorbidities of obesity (i.e., heat stress, adipokines, insulin resistance, changes in lipids, hypogonadism and obstructive sleep apnoea) are also independently associated with increased sperm DNA damage that is not always modified in men with obesity, and as such may provide a causative link to the discrepancies amongst human studies. In this review, we provide an update on the literature regarding the associations between obesity in men and fertility, basic sperm parameters and sperm DNA damage. We further discuss potential reasons for the discrepancies in the literature and outline possible direct and indirect mechanisms of increased sperm DNA damage resulting from obesity. Finally, we summarise intergenerational obesity through the paternal linage and how sperm DNA damage may contribute to the transmission.

A short-term high-fat diet alters rat testicular activity and blood-testis barrier integrity through the SIRT1/NRF2/MAPKs signaling pathways

Background

Overweight/obesity are metabolic disorder resulting from behavioral, environmental, and heritable causes. WHO estimates that 50% of adults and 30% of children and adolescents are overweight or obese, and, in parallel, an ongoing decline in sperm quality and male fertility has been described. Numerous studies demonstrated the intimate association between overweight/obesity and reproductive dysfunction due to a highly intricate network of causes not yet completely understood. This study expands the knowledge on the impact of a short-term high-fat diet (st-HFD) on rat testicular activity, specifically on steroidogenesis and spermatogenesis, focusing on the involved molecular mechanisms related to mitochondrial dynamics, blood-testis barrier (BTB) integrity, and SIRT1/NRF2/MAPKs pathways.

Methods

Ten adult Male Wistar rats were divided into two groups of five and treated with a standard diet or an HFD for five weeks. At the end of the treatment, rats were anesthetized and sacrificed by decapitation. Blood was collected for serum sex hormone assay; one testis was stored at -80ÅãC for western blot analysis, and the other, was fixed for histological and immunofluorescence analysis.

Results

Five weeks of HFD results in reduced steroidogenesis, increased apoptosis of spermatogenic cells, and altered spermatogenesis, as highlighted by reduced protein levels ofmeiotic and post-meiotic markers. Further, we evidenced the compromission of the BTB integrity, as revealed by the downregulation of structural proteins (N-Cadherin, ZO-1, occludin, connexin 43, and VANGL2) other than the phosphorylation of regulative kinases (Src and FAK). At the molecular level, the impairment of mitochondrial dynamics (fission, fusion, andbiogenesis), and the dysregulation of the SIRT1/NRF2/MAPKs signaling pathways, were evidenced. Interestingly, no change was observed in the levels of pro-inflammatory markers (TNFα, NF-kB, and IL-6).

Conclusions

The combined data led us to confirm that overweight is a less severe state than obesity. Furthermore, understanding the molecular mechanisms behind the association between metabolic disorders and male fertility could improve the possibility of identifying novel targets to prevent and treat fertility disorders related to overweight/obesity.

A Comprehensive Review of Phytonutrients as a Dietary Therapy for Obesity

Obesity is a complex medical condition mainly caused by eating habits, genetics, lifestyle, and medicine. The present study deals with traditional diets like the Mediterranean diet, Nordic diet, African Heritage diet, Asian diet, and DASH, as these are considered to be sustainable diets for curing obesity. However, the bioavailability of phytonutrients consumed in the diet may vary, depending on several factors such as digestion and absorption of phytonutrients, interaction with other substances, cooking processes, and individual differences. Hence, several phytochemicals, like polyphenols, alkaloids, saponins, terpenoids, etc., have been investigated to assess their efficiencies and safety in the prevention and treatment of obesity. These phytochemicals have anti-obesity effects, mediated via modulation of many pathways, such as decreased lipogenesis, lipid absorption, accelerated lipolysis, energy intake, expenditure, and preadipocyte differentiation and proliferation. Owing to these anti-obesity effects, new food formulations incorporating these phytonutrients were introduced that can be beneficial in reducing the prevalence of obesity and promoting public health.

Association of living environmental and occupational factors with semen quality in chinese men: a cross-sectional study

Sperm quality can be easily influenced by living environmental and occupational factors. This study aimed to discover potential semen quality related living environmental and occupational factors, expand knowledge of risk factors for semen quality, strengthen men's awareness of protecting their own fertility and assist the clinicians to judge the patient's fertility. 465 men without obese or underweight (18.5 < BMI < 28.5 kg/m2), long-term medical history and history of drug use, were recruited between June 2020 to July 2021, they are in reproductive age (25 < age < 45 years). We have collected their semen analysis results and clinical information. Logistic regression was applied to evaluate the association of semen quality with different factors. We found that living environment close to high voltage line (283.4 × 106/ml vs 219.8 × 106/ml, Cohen d = 0.116, P = 0.030) and substation (309.1 × 106/ml vs 222.4 × 106/ml, Cohen d = 0.085, P = 0.015) will influence sperm count. Experienced decoration in the past 6 months was a significant factor to sperm count (194.2 × 106/ml vs 261.0 × 106/ml, Cohen d = 0.120, P = 0.025). Living close to chemical plant will affect semen PH (7.5 vs 7.2, Cohen d = 0.181, P = 0.001). Domicile close to a power distribution room will affect progressive sperm motility (37.0% vs 34.0%, F = 4.773, Cohen d = 0.033, P = 0.030). Using computers will affect both progressive motility sperm (36.0% vs 28.1%, t = 2.762, Cohen d = 0.033, P = 0.006) and sperm total motility (57.0% vs 41.0%, Cohen d = 0.178, P = 0.009). After adjust for potential confounding factors (age and BMI), our regression model reveals that living close to high voltage line is a risk factor for sperm concentration (Adjusted OR 4.03, 95% CI 1.15-14.18, R2 = 0.048, P = 0.030), living close to Chemical plants is a protective factor for sperm concentration (Adjusted OR 0.15, 95% CI 0.05-0.46, R2 = 0.048, P = 0.001) and total sperm count (Adjusted OR 0.36, 95% CI 0.13-0.99, R2 = 0.026, P = 0.049). Time spends on computer will affect sperm total motility (Adjusted OR 2.29, 95% CI 1.11-4.73, R2 = 0.041, P = 0.025). Sum up, our results suggested that computer using, living and working surroundings (voltage line, substation and chemical plants, transformer room), and housing decoration may association with low semen quality. Suggesting that some easily ignored factors may affect male reproductive ability. Couples trying to become pregnant should try to avoid exposure to associated risk factors. The specific mechanism of risk factors affecting male reproductive ability remains to be elucidated.

Analyzing the Differential Impact of Semen Preparation Methods on the Outcomes of Assisted Reproductive Techniques

Sperm separation plays a critical role in assisted reproductive technology. Based on migration, density gradient centrifugation and filtration, a properly selected sperm could help in increasing assisted reproductive outcomes in teratozoospermia (TZs). The current study aimed to assess the prognostic value of four sperm selection techniques: density gradient centrifugation (DGC), swim-up (SU), DGC-SU and DGC followed by magnetic-activated cell sorting (DGC-MACS). These were evaluated using spermatozoa functional parameters. A total of 385 infertile couples underwent the procedure of intracytoplasmic sperm injection (ICSI), with an isolated teratozoospermia in the male partner. Semen samples were prepared by using one of the mentioned sperm preparation techniques. The improvements in the percentage of normal mature spermatozoa, rate of fertilization, cleavage, pregnancy and the number of live births were assessed. The normal morphology, spermatozoa DNA fragmentation (SDF) and chromatin maturity checked by using chromomycin A3 (CMA3) with DGC-MACS preparation were better compared to the other three methods. Embryo cleavage, clinical pregnancy and implantation were better improved in the DGC-MACS than in the other tested techniques. The DGC-MACS technique helped in the selection of an increased percentage of normal viable and mature sperm with intact chromatin integrity in patients with teratozoospermia.

The bibliometric analysis of studies on intracytoplasmic sperm injection from 2002 to 2021

BACKGROUND

Infertility is estimated to occur in 1 out of every 4-7 couples. Intracytoplasmic sperm injection (ICSI), a type of assisted reproduction introduced in 1992, has been used across the world for almost all indications of infertility, yielding high pregnancy rates. There is a growing concern worldwide about ICSI since semen quality has declined in recent years, accompanied with the potential risks of this technology. This study aims to analyze the current status and hotspots of ICSI via a bibliometric analysis.

METHODS

We retrieved publications on ICSI from the Web of Science Core Collection database from 2002 to 2021. CiteSpace was used to summarize knowledge mapping of subject categories, keywords, and co-citation relationships with the strongest citation bursts. VOSviewer was used to explore co-citation and co-occurrence relationships for countries, organizations, references, authors, and keywords.

RESULTS

A total of 8271 publications were analyzed between 2002 and 2021. The major findings are as follows: the USA, China, Italy, Japan, and Belgium are the top five prolific countries. The Free University of Brussels, University of Copenhagen, University of Valencia, Ghent University, and the University of California San Francisco are the top five contributing organizations. Fertility and Sterility and Human Reproduction are the most productive and cited journals. The hotspot topics are risks of ICSI, oocyte preservation, live birth rate, infertile men, and embryo quality in the past two decades.

CONCLUSION

This study presents a research overview of ICSI from different perspectives. These findings will contribute to a better understanding of the current status of ICSI research and provide hotspots and trends for future studies.

Analysis of sperm chromatin packaging and reproductive biomarker to evaluate the consequence of advanced male age

In this study, the semen parameters, sperm chromatin integrity, antioxidant enzyme levels, and reproductive hormone levels of subfertile male subjects from Pakistan were assessed in relation to their age. Data on the demographic characteristics of the 750 study participants, including their general health, body mass index (BMI), and reproductive status, were collected from subfertile men from Pakistan. Semen and blood were collected to determine standard semen parameters, sperm chromatin dispersion (Halosperm-SCD), sperm chromatin integrity using toluidine blue (TB) staining, sperm chromatin maturity using chromomycin A3 (CMA3+) staining, and reproductive hormone (FSH, LH, prolactin and testosterone levels). The patients were divided into three groups according to their age: Group 1 included male subjects aged 30 years or less (n = 90), Group 2 included male subjects between the ages of 31 and 40 years (n = 330), and Group 3 included male subjects over 40 years of age (n = 330). Conventional semen parameters, reactive oxygen species (ROS), superoxide dismutase (SOD), guaiacol peroxidase (GPX), catalase (CAT), and lipid peroxidation (MDA) did not statistically (p > 0.05) differ with increasing male age or between different age groups. When compared to younger men (<30 years), sperm SCD (23.2 ± 0.88%) was significantly (p = 0.01) lower as compared to male patients aged >40 years (26.6 ± 0.6%). The concentration of LH, FSH, and testosterone levels were comparable between the groups (p > 0.05), while a significant (p = 0.04) increase in sperm chromatin immaturity CMA3+ (30 ± 0.71%) was observed in the old age group (>40 years) compared to the <30-year group (26.6 ± 1.03%). A positive association was observed between advanced male age and sperm chromatin dispersion (SCD) (r = 0.124, p = 0.001) and decondensation (CMA3+) (r = 0.1, p = 0.009). Despite potential limitations, this study has been carried out with extensive information on the potential risk of male age on sperm integrity. The present study demonstrated the impact of male age on male reproductive health, as these patients had a higher percentage of sperm chromatin damage (SCD) in their semen. Sperm DNA damage assessment will help in the evaluation and diagnosis of the underlying cause of poor fertility and can help clinicians in selecting the right treatment options. Male age is one of the factors that have an impact on the decline in male fertility. As a result, it is preferable for patients receiving assisted reproductive technology to be younger.