Longitudinal semen parameter assessments and live birth: variability and implications for treatment strategies

The prevalence of abnormal semen parameters in male partners of women with anovulatory polycystic ovarian syndrome: a retrospective case-control study

PURPOSE

Polycystic ovary syndrome (PCOS) is the leading cause of anovulatory infertility, often requiring ovarian stimulation in affected women attempting to conceive. Male partner semen quality and shared lifestyle factors can significantly impact reproductive outcomes. However, current international guidelines lack evidence-based recommendations on the necessity and timing of semen analysis for the fertility management of anovulatory PCOS women.

METHODS

In a retrospective case-control study, semen analysis results of male partners of 187 anovulatory PCOS women scheduled for ovarian stimulation were analyzed and compared to a control group of 76 male partners of women with bilateral tubal occlusion.

RESULTS

The prevalence of semen analysis results with at least one parameter classified as "borderline" and "pathological" among male partners of women with PCOS eligible to undergo ovarian stimulation was 51.3% and 22.5%, compared to 44.7% and 13.2% in the control group, respectively (p = 0.027). In the PCOS group, male body mass index (odds ratio, OR 1.478, p < 0.001), and smoking status (OR 6.228, p < 0.001) were significant predictors of pathological sperm test results, while no association was observed with any female characteristics (p > 0.05).

CONCLUSION

The high frequency of pathological sperm analysis results provides lacking epidemiological data on semen quality in this population, emphasizing the critical need for early male fertility evaluation prior to ovarian stimulation in PCOS women. Moreover, our findings indicate that the risk prediction for abnormal semen quality cannot be based on the female's data.

Prospective reproductive outcomes according to sperm parameters, including DNA fragmentation, in recurrent pregnancy loss

RESEARCH QUESTION

Are the prospective reproductive outcomes in couples experiencing recurrent pregnancy loss (RPL) related to the sperm DNA fragmentation index (DFI), as measured by sperm chromatin structure assay, sperm morphology and sperm concentration at referral?

DESIGN

This prospective cohort study included 95 couples seen between 1 April 2018 and 1 December 2019 at the tertiary Copenhagen RPL Unit, Copenhagen University Hospital, Rigshospitalet and Hvidovre Hospital, Denmark. The couples had experienced three or more unexplained consecutive pregnancy losses or two late pregnancy losses (>12 weeks gestation). Follow-up was 12-31 months.

RESULTS

Eighty-one of 95 (85.3%) couples achieved pregnancy after referral. In the first pregnancy after referral, 46 (56.8%) couples achieved a live birth, and 35 (43.2%) couples experienced another pregnancy loss. There was no significant difference in baseline DFI between couples that experienced pregnancy loss [median 11.7, interquartile range (IQR) 9.1-17.3] and couples that achieved a live birth (median 12.5, IQR 9.3-16.5; P = 0.971). Improving sperm morphology increased the odds of a live birth after referral (adjusted OR 1.26, 95% CI 1.05-1.52; P = 0.014). DFI and sperm concentration were not associated with the outcome of the first pregnancy after referral. Overall, 35.9% of the men had DFI ≥15 at inclusion. Couples that failed to achieve pregnancy had a higher median DFI of 17.7 (IQR 7.7-27.2) compared with the rest of the cohort (median 12.0, IQR 9.3-16.5; P = 0.041).

CONCLUSIONS

At referral, sperm DFI, morphology and concentration cannot be used to identify RPL couples at risk of another pregnancy loss. Increased baseline DFI was associated with difficulty achieving another pregnancy, and improving sperm morphology was associated with increased odds of a live birth.

Could the sperm epigenome become a diagnostic tool for evaluation of the infertile man?

Although male infertility is currently diagnosed when abnormal sperm parameters are found, the poor predictive ability of sperm parameters on natural fecundity and medically assisted reproduction outcome poses the need for improved diagnostic techniques for male infertility. The accumulating evidence about the role played by the sperm epigenome in modulation of the early phases of embryonic development has led researchers to focus on the epigenetic mechanisms within the sperm epigenome to find new molecular markers of male infertility. Indeed, sperm epigenome abnormalities could explain some cases of unexplained male infertility in men showing normal sperm parameters and were found to be associated with poor embryo development in IVF cycles. The present mini-review summarizes the current knowledge about this interesting topic, starting from a description of the epigenetic mechanisms of gene expression regulation (i.e. DNA methylation, histone modifications, and non-coding RNAs' activity). We also discuss possible mechanisms by which environmental factors might cause epigenetic changes in the human germline and affect embryonic development, as well as subsequent generations' phenotypes. Studies demonstrating sperm epigenome abnormalities in men with male infertility are reviewed, with particular emphasis on those with the more severe form of spermatogenic dysfunction. Observations demonstrate that the diagnostic and prognostic efficacy of sperm epigenome evaluation will help facilitate the management of men with male factor infertility.

Is There Any Effect of Change in Pre-Wash and Post-Wash Semen Parameters on the Success of Intrauterine Insemination?

(1) Background: We aimed to investigate the effect of change in pre-wash and post-wash semen parameters on intrauterine insemination (IUI) success in a homogenous study group. (2) Methods: IUI cycles conducted at an infertility clinic were included in this study. Patient records were examined retrospectively. Δ sperm count (per mL) was calculated as [pre-wash sperm count (per mL)-post-wash sperm count (per mL)]. Δ Total progressive motile sperm count (TPMSC) was also calculated as (post-wash TPMSC-pre-wash TPMSC). (3) Results: No statistically significant difference was detected in terms of Δ sperm count (p = 0.38), and Δ TPMSC (p = 0.76) regarding the clinical pregnancy rate (CPR). There was no statistically significant difference between CPR (+) and CPR (-) groups in terms of post-wash sperm count, TPMSC, TPMSC ≥ 10 × 10⁶, TPMSC ≥ 5 × 10⁶ (p = 0.65, p = 0.79, p = 0.49, p = 0.49, respectively). The live birth rate (LBR) showed no statistically significant differences except for a pre-wash TPMSC ≥ 10 × 10⁶ (p = 0.02). Through the performed ROC analysis, no statistically significant cutoff value could be set for the pre-wash TPMSC. (4) Conclusions: There is only a pre-wash TPMSC ≥ 10 × 10⁶ that showed a significant role in the success of IUI, even when considering all other pre-wash and post-wash semen parameters. Δ sperm count and Δ are not useful markers for IUI success.

Small Non-Coding RNAs in Male Reproduction

Male reproductive functions are strictly regulated in order to maintain sperm production and fertility. All processes are controlled by precise regulation of gene expression, which creates specific gene expression programs for different developmental stages and cell types, and forms the functional basis for the reproductive system. Small non-coding RNAs (sncRNAs) are involved in gene regulation by targeting mRNAs for translational repression and degradation through complementary base pairing to recognize their targets. This review article summarizes the current knowledge on the function of different classes of sncRNAs, in particular microRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs), during male germ cell differentiation, with the focus on sncRNAs expressed in the germline. Although transcriptionally inactive, mature spermatozoa contain a complex population of sncRNAs, and we also discuss the recently identified role of sperm sncRNAs in the intergenerational transmission of epigenetic information on father's environmental and lifestyle exposures to offspring. Finally, we summarize the current information on the utility of sncRNAs as potential biomarkers of infertility that may aid in the diagnosis and prediction of outcomes of medically assisted reproduction.

The effect of various air pollution and participants' age on semen quality in southern Taiwan

OBJECTIVE

This study aimed to investigate the association between semen quality and air pollution in southern Taiwan.

MATERIALS AND METHODS

In this retrospective study, 4338 males aged 21-70 years were recruited between 2001 and 2018 from a reproductive medical center. Semen quality was assessed according to standardized methods outlined in the World Health Organization (WHO) Laboratory Manual 1999 and 2010, including total sperm count, progressive sperm motility (%), rapid progressive sperm motility (%), and sperm with normal morphology (%). All designated national air quality automatic continuous monitoring stations measured the levels of air pollution [particulate matter (PM10 and PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3)], and was documented by Environmental Protection Administration in Taiwan. We collected data on the levels of air pollution based on the participants' residential addresses.

RESULTS

In our study, we found that progressive and rapid progressive sperm motility significantly decreased annually (p < 0.05). In addition, increasing age influenced total sperm count, progressive sperm motility, rapid progressive sperm motility, and sperm with normal morphology (p < 0.05). Among different air pollution, we observed SO2 was associated with lower rapid progressive sperm motility and lower sperm with normal morphology (β = -0.103, p = 0.043; β = 0.118, p = 0.001, respectively). However, NO2 was associated with higher rapid progressive sperm motility and a high number of sperm with normal morphology (β = 0.129, p = 0.002; β = 0.127, p < 0.001, respectively).

CONCLUSIONS

The semen quality in southern Taiwan appears to have declined in recent years. The participant's age for semen analysis was most strongly associated with semen parameters, Moreover, a significant association between SO2 and NO2 levels and semen motility was observed, even after adjusting for multiple comparisons. Further study is required to analyze the dose-dependent effect of SO2 and NO2 on semen parameters.

A comparison between the Felix™ electrophoretic system of sperm isolation and conventional density gradient centrifugation: a multicentre analysis

PURPOSE

Developing optimized techniques for the isolation of human spermatozoa possessing low levels of DNA damage is an important objective for the ART industry. The purpose of this study was to compare a novel electrophoretic system (Felix™) of sperm isolation with a conventional method involving density gradient centrifugation (DGC).

METHODS

Five international ART Centres in Australia, India, Sweden, the USA, and China have collaborated in order to compare the quality of the sperm populations isolated by Felix™ and DGC in terms of processing time, sperm concentration, motility, vitality, and DNA integrity as assessed by 3 methods: SCSA, Halo, and TUNEL.

RESULTS

Across all centers, 112 comparisons were performed. Although significant differences were noted between centers in terms of the quality of the semen samples subjected for analysis, overall, both methods were equally capable of isolating populations of spermatozoa exhibiting high levels of vitality and progressive motility. The absolute numbers of spermatozoa recovered were significantly (p < 0.001) lower with the Felix™ device although sperm quality was higher with 4/5 centers reporting a significant improvement in DNA integrity relative to DGC (p < 0.01-p < 0.001). In practical terms, the Felix™ device featured a standardized 6 min preparation time whereas clinical DGC protocols varied from center to center but generally took around 40 min to complete.

CONCLUSIONS

The Felix™ device is a positive technical development capable of isolating suspensions of highly motile spermatozoa exhibiting low levels of DNA damage in a fraction of the time taken by conventional procedures such as DGC.