Increasing paternal age and ejaculatory abstinence length negatively influence the intracytoplasmic sperm injection outcomes from egg‐sharing donation cycles

Advanced Paternal Age in Focus: Unraveling Its Influence on Assisted Reproductive Technology Outcomes

As global demographics shift toward increasing paternal age, the realm of assisted reproductive technologies (ARTs), particularly in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), faces new challenges and opportunities. This study provides a comprehensive exploration of the implications of advanced paternal age on ART outcomes. Background research highlights the social, cultural, and economic factors driving men toward later fatherhood, with a focus on the impact of delayed paternity on reproductive outcomes. Methods involve a thorough review of existing literature, centering on changes in testicular function, semen quality, and genetic and epigenetic shifts associated with advancing age. Study results point to intricate associations between the father's age and ART outcomes, with older age being linked to diminished semen quality, potential genetic risks, and varied impacts on embryo quality, implantation rates, and birth outcomes. The conclusions drawn from the current study suggest that while advanced paternal age presents certain risks and challenges, understanding and mitigating these through strategies such as sperm cryopreservation, lifestyle modifications, and preimplantation genetic testing can optimize ART outcomes. Future research directions are identified to further comprehend the epigenetic mechanisms and long-term effects of the older father on offspring health. This study underscores the need for a comprehensive approach in navigating the intricacies of delayed fatherhood within the context of ART, aiming for the best possible outcomes for couples and their children.

Male reproductive ageing: a radical road to ruin

In modern post-transition societies, we are reproducing later and living longer. While the impact of age on female reproductive function has been well studied, much less is known about the intersection of age and male reproduction. Our current understanding is that advancing age brings forth a progressive decline in male fertility accompanied by a reduction in circulating testosterone levels and the appearance of age-dependent reproductive pathologies including benign prostatic hypertrophy and erectile dysfunction. Paternal ageing is also associated with a profound increase in sperm DNA damage, the appearance of multiple epigenetic changes in the germ line and an elevated mutational load in the offspring. The net result of such changes is an increase in the disease burden carried by the progeny of ageing males, including dominant genetic diseases such as Apert syndrome and achondroplasia, as well as neuropsychiatric conditions including autism and spontaneous schizophrenia. The genetic basis of these age-related effects appears to involve two fundamental mechanisms. The first is a positive selection mechanism whereby stem cells containing mutations in a mitogen-activated protein kinase pathway gain a selective advantage over their non-mutant counterparts and exhibit significant clonal expansion with the passage of time. The second is dependent on an age-dependent increase in oxidative stress which impairs the steroidogenic capacity of the Leydig cells, disrupts the ability of Sertoli cells to support the normal differentiation of germ cells, and disrupts the functional and genetic integrity of spermatozoa. Given the central importance of oxidative stress in defining the impact of chronological age on male reproduction, there may be a role for antioxidants in the clinical management of this process. While animal studies are supportive of this strategy, carefully designed clinical trials are now needed if we are to realize the therapeutic potential of this approach in a clinical context.

Short-interval second ejaculation improves sperm quality, blastocyst formation in oligoasthenozoospermic males in ICSI cycles: a time-lapse sibling oocytes study

Background

Does short-interval second ejaculation improve sperm quality, embryo development and clinical outcomes for oligoasthenozoospermia males received intracytoplasmic sperm injection (ICSI) treatment?

Methods

All enrolled male patients underwent short-interval secondary ejaculation on the day of oocyte retrieval, and 786 sibling MII oocytes from 67 cycles were equally divided into two groups based on whether the injected spermatozoons originated from the first or second ejaculation. Semen parameters, embryo development efficiency, morphokinetic parameters and clinical outcomes were compared between the two groups to assess the efficiency and clinical value of short-interval second ejaculation in ICSI cycles.

Results

Short-interval second ejaculation significantly improved sperm motility, normal morphological rate, and sperm DNA integrity both before and after sperm swim-up. The high-quality blastocyst rate (24.79% versus 14.67%), available blastocyst rate (57.56% versus 48.44%), and oocyte utilization rate (52.93% versus 45.29%) were significantly higher in the second ejaculation group (P<0.05). The clinical pregnancy rate (59.09% versus 47.37%), implantation rate (42.11% versus 32.35%) and live birth rate (40.91% versus 31.58%) were higher in the second ejaculation group, but the differences were not significant (P>0.05). Time-lapse analysis showed that morphokinetic time points after the 7-cell stage were earlier in the second ejaculation group but without a significant difference (P>0.05), and abnormal embryo cleavage patterns between the two groups were not significantly different (P>0.05).

Conclusions

Short-interval second ejaculation significantly improves sperm quality in oligoasthenozoospermic males, and is beneficial for blastocyst formation efficiency in ICSI cycles. This study suggested a non-invasive and simple but effective strategy for improving ICSI treatment outcomes.

Sperm cryopreservation does not affect live birth rate in normozoospermic men: analysis of 7969 oocyte donation cycles

STUDY QUESTION

Does sperm cryopreservation influence the reproductive outcomes of normozoospermic patients in oocyte donation cycles?

SUMMARY ANSWER

After controlling for confounders, the use of cryopreserved semen from normozoospermic patients does not affect pregnancy and live birth rates after elective ICSI.

WHAT IS KNOWN ALREADY

Sperm cryopreservation by slow freezing is a common practice in ART. While frozen-thawed semen typically presents reduced motility and vitality, its use for ICSI is generally considered adequate in terms of reproductive outcomes. Nevertheless, most studies comparing reproductive outcomes between fresh and cryopreserved sperm include patients with severe male factor (testicular sperm, oligo-, and/or asthenozoospermia) or women of advanced maternal age, where the altered quality of the gametes can partially mask the full effect of freezing/thawing.

STUDY DESIGN, SIZE, DURATION

The study included a retrospective cohort of 7969 couples undergoing their first oocyte donation cycle between January 2013 and December 2019 in one large clinic, using normozoospermic semen from the male partner. All cycles involved elective ICSI, fresh oocytes, and a fresh embryo transfer, either at cleavage or blastocyst stage. Two study groups were established based on the sperm status: fresh (n = 2865) and cryopreserved (n = 5104).

PARTICIPANTS/MATERIALS, SETTING, METHODS

A slow freezing protocol was used for all sperm cryopreservation. Sperm washing, capacitation, and selection prior to ICSI were performed identically for fresh and frozen-thawed samples, using pellet swim-up. Fertilization rate (FR), pregnancy (biochemical and ongoing), and live birth rates were compared between study groups using univariate and multivariate regression analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

Male and female age, sperm concentration and motility after ejaculation, and number of oocytes inseminated were similar between cycles using fresh or cryopreserved sperm. Analysis by Student's t-test did not indicate a significant difference in FR between fresh and cryopreserved sperm (P = 0.0591); however, after adjusting for confounders, this difference reached statistical significance: 74.65% FR for fresh (CI 95%: 73.92-75.38) versus 73.66% for cryopreserved sperm (CI 95%: 73.11-74.20), P = 0.0334. The adjusted regression analysis revealed higher odds of biochemical pregnancy when using fresh sperm (odds ratio (OR): 1.143, P = 0.0175), but no significant effects of sperm cryopreservation were observed for ongoing pregnancy (OR: 1.101, P = 0.0983) and live birth (OR: 1.082, P = 0.1805).

LIMITATIONS, REASONS FOR CAUTION

Caution should be exerted when extrapolating these results to different protocols for sperm cryopreservation and selection, or to IVM, advanced maternal age and classical IVF cycles, which were excluded from analysis. Owing to the retrospective nature of the study, some uncontrolled for variables may affect the results.

WIDER IMPLICATIONS OF THE FINDINGS

Sperm cryopreservation does not affect pregnancy and live birth rates in normozoospermic patients, and although it may lower FR s slightly, this would not be clinically relevant. In line with previous studies that included patients with an apparent male or female factor, sperm cryopreservation is a safe and convenient technique.

STUDY FUNDING/COMPETING INTEREST(S)

The study received no external funding and all authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Effect of paternal age on assisted reproductive outcomes in ICSI donor cycles

BACKGROUND

Despite growing evidence suggesting age-related molecular changes in gametes, the impact of paternal age on clinical outcomes during infertility treatments has not been adequately assessed.

OBJECTIVES

This study aims to assess the correlation of paternal age to clinical pregnancy and live birth rates in egg donation cycles undergoing intracytoplasmic sperm injection.

MATERIALS AND METHODS

This retrospective cohort study includes 4930 fresh oocyte donation cycles from 3995 couples between April 2005 and February 2020 in a private IVF hospital. Clinical pregnancy and live birth rates were the primary outcome measures. The results were also assessed according to the paternal age groups, donor characteristics, semen parameters, fertilization rate, and quality of the transferred embryos.

RESULTS

The age and body mass index of the donors, oocyte maturation, fertilization rates, and the mean number of transferred embryo quality were comparable on day-3 but not on day-5 embryo transfers between paternal age groups (p > 0.05). Paternal age was found to be negatively correlated to the number of oocytes utilized, normal semen parameters, fertilization, clinical pregnancy, and live birth rates (p < 0.05). In day-5 embryo transfer cycles, only the rate of cycles with normal spermatozoa, number of allocated oocytes, and pregnancy were found to be statistically significant.

DISCUSSION AND CONCLUSION

Paternal age may influence reproductive outcomes and should be considered during infertility evaluations in intracytoplasmic sperm injection donor cycles. Further research is needed to confirm these findings.

Does paternal age affect the live birth rate in donor oocyte cycles? A systematic review and meta-analysis

PURPOSE

While delayed parenthood is increasing worldwide, the effect of paternal age on in vitro fertilization (IVF) outcomes remains unclear. The egg donation model appears to be relevant to studying the independent impact of paternal age on clinical outcome, but the available studies are heterogeneous and contradictory. This systematic review and meta-analysis aimed to assess the relationship between paternal age and live birth rate (LBR) in egg donation cycles.

METHODS

A systematic search of the literature was conducted in PubMed, Embase, and the Cochrane Library from inception to June 30, 2021. All studies on egg donation cycles where LBR is reported according to male age were included. Study selection, bias assessment, and data extraction were performed by two independent reviewers according to the Cochrane methods.

RESULTS

Eleven studies involving 10,527 egg donation cycles were finally included. The meta-analysis showed a slight but significant and linear decrease in LBR with increasing paternal age (estimate - 0.0055; 95% CI (- 0.0093; - 0.0016), p = 0.006), with low heterogeneity (I2 = 25%). No specific threshold was identified. A similar trend toward decreased clinical pregnancy rate with advancing paternal age was found but did not reach statistical significance (p = 0.07).

CONCLUSION

This meta-analysis demonstrates that increasing paternal age is associated with a slight but significant and linear decrease in the live birth rate in egg donation cycles, with no apparent threshold effect. Although this requires further confirmation, this information is important for counseling men who are considering delayed childbearing.

Male Age and Progressive Sperm Motility Are Critical Factors Affecting Embryological and Clinical Outcomes in Oocyte Donor ICSI Cycles

This retrospective cohort study aimed to explore whether paternal age and semen quality parameters affect the embryological and clinical outcomes of ICSI with oocyte donation. A total of 339 oocyte donation (OD)-ICSI cycles were categorized into four groups according to the semen parameter profiles of the male counterparts: normozoospermia (NS, n = 184), oligozoospermia (OS, n = 41), asthenozoospermia (AS, n = 50), and oligoasthenozoospermia (OAS, n = 64). The effect of age, total sperm count, and progressive motility was separately analyzed for reproductive outcomes and compared between the study groups: fertilization, blastulation, and top-quality embryo rate, biochemical and clinical pregnancy, live birth, and miscarriage. A negative correlation between male age and fertilization rate was observed (r_s =  - 0.23, p < 0.0001), while male age was a significant factor for biochemical pregnancy (p = 0.0002), clinical pregnancy (p = 0.0017), and live birth (p = 0.0038). Reduced total sperm count and lowered progressive motility led to poorer fertilization rates (r_s = 0.19 and 0.35, respectively, p < 0.0001) and affected embryo quality (r_s = 0.13, p = 0.02, and r_s = 0.22, p < 0.0001, respectively). OD-ICSI cycles with asthenozoospermia had significantly lowered success rates in biochemical pregnancy, clinical pregnancy, and live birth (p < 0.05). Our study demonstrated that both advanced male age and reduced progressive motility of spermatozoa exert a significant negative influence on the outcome of assisted reproduction, even in controlled procedures with gamete selection and optimization such as in OD-ICSI. Improvement in treatment strategies and male fertility evaluation requires incorporation of such evidence to obtain better prognosis towards personalized management.

Early and late paternal contribution to cell division of embryos in a time-lapse imaging incubation system

The objective of this study was to investigate the impact of male age, semen quality and days of ejaculatory abstinence on embryo morphokinetics. A total of 1,220 zygotes obtained from 139 couples in a private in vitro fertilisation centre were analysed. The timing of specific events from the point of insemination, such as timings to pronuclei appearance and fading, to two, three, four, five, six, seven and eight cells and to blastulation were recorded. Multivariate linear regression analysis was used to evaluate the influence of paternal factors on embryo morphokinetic events. Paternal age was positively correlated with delayed cell cleavage and blastulation, and negatively associated with implantation rate, and clinical pregnancy and live-birth chances. The ejaculatory abstinence was inversely correlated with the implantation rate. Inverse relationships were observed between semen parameters (sperm count, progressive sperm motility, total motile sperm count and morphology) and the timing of specific events during embryo development. Sperm morphology was also positively associated with implantation rate and pregnancy and live-birth chances. Increased paternal age and ejaculatory abstinence, and poor semen quality correlate with delayed cell cleavage and blastulation and negatively impact intracytoplasmic sperm injection outcomes.

Two subsequent seminal productions: A good strategy to treat very severe oligoasthenoteratozoospermic infertile couples

BACKGROUND

Sexual abstinence is considered one of the several factors that influence sperm quality. Recent studies show that a shortening of the abstinence period could be beneficial mostly in oligoasthenoteratozoospermic (OAT) patients.

OBJECTIVE

Retrospective study to verify the efficacy of a second semen sample after a short abstinence to treat severe OAT infertile patients.

MATERIALS AND METHODS

127 couples treated between May 2014 and May 2018 were divided into two groups. Study Group 1 (75 cycles): severe OAT characteristics: count <0.2 × 10⁶ /mL no progressive motility; count ≥0.2 × 10⁶ /mL and no total or progressive motility; 0% normal morphology; a second semen sample was requested after abstinence of 2 h. Control Group 0 (52 cycles): normozoospermic or mild OAT; only one sample was requested. Intracytoplasmic sperm injection was utilized in all cases.

RESULTS

All semen parameters were significantly different between Group 0 vs both samples of Group 1 (p < 0.001), excluding volume between Group 0 and 1st sample of Group 1 (p = 0.682). The comparison between 1st and 2nd samples from Group 1 showed significant differences in volume, total and progressive motility and morphology (p < 0.001, p < 0.001, p < 0.020) but not in total sperm count (p = 0.970). Fertilization, pregnancy rate/transfer, implantation and miscarriage rates were 85.9% and 61.1% (p < 0.001), 30.6% and 35.8% (p = 0.700), 17.5% and 24.0 (p = 0.292), 20.0% and 25.0% (p = 0.017) in Group 0 and Group 1 respectively.

DISCUSSION AND CONCLUSION

The results show that a short abstinence in severe OAT patients allows us to obtain spermatozoa with better motility. The request for a second semen sample in couples with extreme semen parameters is a valid and simple strategy that helps to achieve the same probability of pregnancy compared to a Control Group. Furthermore, it allows us to utilize fresh spermatozoa avoiding the need to resort to cryopreserved reserves or testicular surgery.