The effect of advancing paternal age on pregnancy and live birth rates in couples undergoing in vitro fertilization or gamete intrafallopian transfer

High risk of low birth weight in couples with advanced paternal age in in vitro fertilization treatment

BACKGROUND

With the development of socio-economic conditions and a shift in attitudes towards fertility, there has been a gradual increase in delayed childbearing since the 2000s. Age plays a significant role in the decline of fertility. However, we know very little about the association of paternal age with reproductive outcomes.

OBJECTIVES

To investigate the correlation between advanced paternal age and semen quality, embryo quality, pregnancy, and neonatal outcomes in IVF cycles.

MATERIALS AND METHODS

In this study, after excluding female partners aged ≥35 years, we analyzed data from 761 infertile couples who underwent in vitro fertilization cycles at the First Affiliated Hospital of USTC between June 2020 and March 2023. Cases were classified into three groups according to the age of the male: <35 years (530 infertile couples), 35 years ≤ paternal age <40 years (125 infertile couples), and ≥40 years (106 infertile couples). Then, we compared the general clinical data arising from in vitro fertilization cycles between the three groups, including semen parameters, embryonic parameters, and pregnancy and neonatal birth outcomes.

RESULTS

Data analysis showed that the duration of infertility and the incidence of secondary infertility were significantly higher in paternal age ≥35 years groups than those aged <35 years (all p < 0.05). We also observed a significant difference between ≥40 years and <35 years groups in terms of the normal fertilization rate, high-quality embryo rate, clinical pregnancy rate, miscarriage rate, live birth rate, Apgar scores, and the low birth weight neonatal rate (all p < 0.05). The group with paternal age ≥40 years showed statistically significant differences in terms of clinical pregnancy rate, miscarriage rate, live birth rate, and low birth weight on multivariable logistic regression (all p < 0.05).

CONCLUSION

The results of our study indicate that advanced paternal age (≥40 years) has a significant impact on the embryo quality, pregnancy outcome, and neonatal outcome. Paternal age over 40 years is a risk for in vitro fertilization success rate.

Associations between Advanced Paternal Age and Adverse Reproductive Outcomes in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b)

OBJECTIVE

 The association between paternal age and adverse pregnancy outcomes (APOs) has not been well studied. We sought to determine whether advanced paternal age (APA) is associated with adverse maternal or neonatal outcomes.

STUDY DESIGN

 Secondary analysis of 8,863 pregnancies from the Nulliparous Pregnancy Outcomes Study Monitoring Mothers-to-Be (nuMoM2b) prospective cohort in which both maternal and paternal age at conception were known. APA was defined as age ≥ 40 years and AMA was defined as age ≥ 35 years. Composite maternal and fetal/neonatal APO outcomes were adjudicated by experts using previously defined methods. Univariable and multivariable logistic regression models were used to estimate the associations between APA, AMA, and their combination (AMA and APA), with the outcomes of interest (APO, fetal/neonatal, and combined APO or fetal/neonatal outcomes). Multivariable analyses were adjusted for covariates identified a priori: self-reported race and ethnicity, education, body mass index, maternal medical conditions, assisted reproductive technology (ART), and maternal age in APA only models.

RESULTS

 APA in isolation was not significantly associated with maternal or fetal/neonatal adverse outcomes (adjusted odds ratio [aOR] = 1.08, 95% confidence interval [CI]: 0.89 - 1.32). In contrast, AMA pregnancies and pregnancies in which both parents were of advanced age were associated with significantly increased risk of maternal or fetal/neonatal adverse outcome (aOR = 1.37, 95% CI: 1.17 - 1.59, p < 0.001 and aOR = 1.60, 95% CI: 1.25 - 2.05, p < 0.001), respectively. Findings were similar when individuals who used assisted reproductive technology (ART) were excluded from analyses.

CONCLUSION

 In our study of nulliparous birthing people, in contrast to AMA pregnancies, APA alone was not significantly associated with a heightened risk of maternal or fetal/neonatal APOs. However, pregnancies from both AMA and APA individuals demonstrated a trend toward a higher risk of APOs compared with AMA pregnancies. Further research is needed to delineate the mechanism driving this finding.

KEY POINTS

· There is an established association between older maternal age and increased risk of adverse pregnancy outcomes. Determining the influence of paternal age on pregnancy outcomes is of equal importance.. · Prior data are inconclusive on the association of APA and rates of miscarriage, fertilization rates, and aneuploidy, and to our knowledge, the associations with adverse pregnancy outcomes have not been previously examined.. · This study examines if APA (paternal age ≥ 40 years) is an independent risk factor for adverse pregnancy outcomes in a cohort of nulliparous birthing people..

Effect of aging on semen and embryonic developmental scores in assisted reproductive technology

Purpose

The effects of female aging on fertility have been extensively studied; however, this is not the case for aging males. Embryonic selection using time-lapse observations is helpful for successful embryo transfer; however, information on the effect of male aging on time-lapse is insufficient. We analyzed the impact of paternal aging on sperm characteristics, embryonic developmental kinetics, embryo evaluation score, and pregnancy outcomes.

Methods

We used data from patients treated at our clinic between January 2020 and December 2022. We evaluated the effects of aging in men and women on semen data, in vitro fertilization (IVF) results, developmental kinetics, embryo evaluation scores, and embryo transfer outcomes using a retrospective approach.

Results

Male aging adversely affected the semen characteristics. Although female aging had adverse effects on IVF, embryonic developmental kinetics, and embryo transfer outcomes, male aging did not have such a significant impact. Female aging decreased the iDAScore and Gardner criteria, whereas male aging did not affect the iDAScore.

Conclusions

Aging in males had a negative effect on semen data. Contrary to the impact of aging on women, aging in men did not have a significant effect on embryo and gestation rates following embryo transfer.

Effect of paternal age on clinical outcomes of in vitro fertilization-embryo transfer cycles

Purpose

This study aimed to investigate the impact of paternal age > 40 years on clinical pregnancy and perinatal outcomes among patients undergoing in vitro fertilization treatment.

Methods

We selected 75 male patients (aged > 40 years) based on predefined inclusion and exclusion criteria. Propensity score matching was performed in a 1:3 ratio, resulting in a control group (aged ≤ 40 years) of 225 individuals. Various statistical tests, including the Mann-Whitney U test, Chi-square test, Fisher's exact test, and binary logistic regression, were used to analyze the association between paternal age and clinical outcomes.

Results

We found no statistically significant differences in semen routine parameters, clinical pregnancy outcomes, and perinatal outcomes between paternal aged > 40 and ≤ 40 years. However, in the subgroup analysis, the live birth rate significantly decreased in those aged ≥ 45 compared to those aged 41-42 and 43-44 years (31.25% vs. 69.23% and 65%, respectively; all p < 0.05). Additionally, the clinical pregnancy rate was significantly lower among those aged ≥ 45 than among those aged 41-42 (43.75% vs. 74.36%; p=0.035).

Conclusion

Paternal age ≥ 45 years was associated with lower live birth and clinical pregnancy rates.

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.

Paternal age does not jeopardize the live birth rate and perinatal outcomes after in vitro fertilization: an analysis based on 56,113 frozen embryo transfer cycles

BACKGROUND

The global trend of delaying childbearing has led to an increasing number of couples seeking in vitro fertilization. The adverse effects of advanced maternal age on pregnancy and perinatal outcomes are well documented, regardless of the conception method. In addition, advanced paternal age may contribute to poor reproductive potential because of high levels of sperm DNA fragmentation. However, it remains challenging to guide older men regarding the effect of paternal age on pregnancy and birth outcomes in the field of assisted reproduction.

OBJECTIVE

This study aimed to investigate the association of paternal age with live birth and perinatal outcomes following in vitro fertilization-frozen embryo transfer.

STUDY DESIGN

A retrospective study was performed at a university-affiliated fertility center, involving women who were younger than 36 years and had undergone frozen embryo transfer from January 2011 to June 2021. Subjects were categorized into 6 groups based on paternal age: <25, 25 to 29, 30 to 34, 35 to 39, 40 to 44, and ≥45 years. A generalized estimating equation logistic regression model was used to account for the clustered nature of data and to adjust for confounders. Paternal age between 25 and 29 years served as the reference group in the logistic regression models.

RESULTS

A total of 56,113 cycles who met the inclusion criteria were included in the final analysis. On unadjusted analyses, the reproductive outcome parameters showed a considerable decline with increasing male age. The live birth rate decreased from 47.9% for men aged 25 to 29 years to 40.3% among men aged ≥40 years. Similarly, the clinical pregnancy rate decreased from 54.4% in the reference group to 47.8% in the ≥40 years age group. Conversely, the miscarriage rate increased as male age increased, from 10.2% among men aged 25 to 29 years to 13.5% among men aged ≥45 years. However, the differences in the reproductive outcomes mentioned above were no longer significant in the multivariable models. Compared with the younger controls, advanced paternal age was not associated with a lower chance of live birth (males aged 40-44 years: adjusted odds ratio, 0.94; 95% confidence interval, 0.85-1.04; males aged ≥45 years: adjusted odds ratio, 0.93; 95% confidence interval, 0.79-1.10). In addition, the rates of clinical pregnancy (males aged 40-44 years: adjusted odds ratio, 0.95; 95% confidence interval, 0.85-1.05; males aged ≥45 years: adjusted odds ratio, 0.94; 95% confidence interval, 0.79-1.12) and miscarriage (males aged 40-44 years: adjusted odds ratio, 1.05; 95% confidence interval, 0.85-1.31; males aged ≥45 years: adjusted odds ratio, 1.07; 95% confidence interval, 0.77-1.50) were comparable between the reference and advanced paternal age groups. Furthermore, men in the youngest age group (<25 years) did not have worse pregnancy outcomes than those in the reference group. Regarding perinatal outcomes, there was no difference among the study cohorts in terms of preterm birth, low birthweight, macrosomia, small for gestational age, and large for gestational age, both in the unadjusted and confounder-adjusted models.

CONCLUSION

This study did not demonstrate a significant association between paternal age and live birth and perinatal outcomes after in vitro fertilization-frozen embryo transfer when the female partners were younger than 36 years. With the global trend toward delaying childbirth, our findings provide useful information for counseling patients that increasing paternal age may not adversely affect pregnancy and perinatal outcomes in assisted reproduction.

Association of overweight and obesity with cumulative live birth rates according to women's age: A cohort study of 26 567 treatment cycles

OBJECTIVE

To evaluate the effect of age on the association between maternal body mass index (BMI) and cumulative live birth rates (CLBRs) following in vitro fertilization treatment.

METHOD

We retrospectively analyzed the data of 26 567 women undergoing in vitro fertilization/intracytoplasmic sperm injection from 2016 to 2019. We conducted multivariate regression analysis of the association between CLBRs and maternal BMI and age category.

RESULTS

A total of 16 626 (62.58%) patients achieved a live birth. Women with obesity had significantly decreased CLBRs compared with women who had normal weight (odds ratio [OR] 0.73 [95% confidence interval (CI), 0.66-0.80]). The significant interaction between age and BMI suggested that the impact of BMI on CLBRs was moderated by women's age (P interaction <0.001). The association between obesity and CLBRs was inverse among women aged <30 years (OR, 0.63 [95% CI, 0.54-0.73]), 30 to 34 years (OR, 0.79 [95% CI, 0.67-0.93]), and 35 to 37 years (OR, 0.71 [95% CI, 0.52-0.98]); however, decreases in CLBRs with obesity were not observed in women aged 38 to 40 years (OR, 1.17 [95% CI, 0.70-1.94]) and ≥ 41 years (OR, 1.25 [95% CI, 0.53-2.96]).

CONCLUSION

Maternal obesity was significantly associated with a lower likelihood of having a live birth, but the risk differed according to women's age. A higher BMI might have a less-pronounced detrimental effect with increasing age.

Epigenetic aging of mammalian gametes

The process of aging refers to physiological changes that occur to an organism as time progresses and involves changes to DNA, proteins, metabolism, cells, and organs. Like the rest of the cells in the body, gametes age, and it is well established that there is a decline in reproductive capabilities in females and males with aging. One of the major pathways known to be involved in aging is epigenetic changes. The epigenome is the multitude of chemical modifications performed on DNA and chromatin that affect the ability of chromatin to be transcribed. In this review, we explore the effects of aging on female and male gametes with a focus on the epigenetic changes that occur in gametes throughout aging. Quality decline in oocytes occurs at a relatively early age. Epigenetic changes constitute an important part of oocyte aging. DNA methylation is reduced with age, along with reduced expression of DNA methyltransferases (DNMTs). Histone deacetylases (HDAC) expression is also reduced, and a loss of heterochromatin marks occurs with age. As a consequence of heterochromatin loss, retrotransposon expression is elevated, and aged oocytes suffer from DNA damage. In sperm, aging affects sperm number, motility and fecundity, and epigenetic changes may constitute a part of this process. 5 methyl-cytosine (5mC) methylation is elevated in sperm from aged men, but methylation on Long interspersed nuclear elements (LINE) elements is reduced. Di and trimethylation of histone 3 lysine 9 (H3K9me2/3) is reduced in sperm from aged men and trimethylation of histone 3 lysine 27 (H3K27me3) is elevated. The protamine makeup of sperm from aged men is also changed, with reduced protamine expression and a misbalanced ratio between protamine proteins protamine P1 and protamine P2. The study of epigenetic reproductive aging is recently gaining interest. The current status of the field suggests that many aspects of gamete epigenetic aging are still open for investigation. The clinical applications of these investigations have far-reaching consequences for fertility and sociological human behavior.

Expression profiles of circular RNAs in spermatozoa from aging men

BACKGROUND

Advanced paternal age (APA) is associated with decreased fertility, but the mechanism underlying APA remains unknown. CircRNAs have been reported to be ideal candidate biomarkers for diagnostic and therapeutic applications in many diseases and are also involved in spermatogenesis. Hence, we aimed to assess the circRNA expression profile of spermatozoa from aging men.

METHODS AND RESULTS

We recruited 6 subjects, including 3 in the younger group (men age < 40) and 3 in the APA group (men age ≥ 40). RNA sequencing was exploited to identify the expression profiles of circRNAs between the two groups. The expression levels of circRNAs were validated using real-time quantitative polymerase chain reaction (RT-qPCR). Kyoto Encyclopedia of Genes and Genomes biological pathway analysis and Gene Ontology analysis were performed to evaluate the functions of differentially expressed circRNAs (DE-circRNAs) between the two groups. In total, 18,787 circRNAs were sequenced in the spermatozoa of two groups. Our analysis revealed that there were 1056 downregulated circRNAs and 1228 upregulated circRNAs between the two groups, and KEGG analysis showed they were mainly involved in pathways including the DNA repair signaling pathway, meiotic recombination signaling pathway, and PI3K/AKT signaling pathway.

CONCLUSIONS

In conclusion, our study suggested that circRNAs play a vital role in spermatozoa from aging men and provided a fresh perspective on the specific regulatory mechanism of spermatozoa from aging men.

Impact of paternal age on assisted reproductive technology outcomes and offspring health: a systematic review

BACKGROUND

The increase in paternal age and the percentage of births after assisted reproductive technologies (ART) may have consequences on offspring and society's position regarding access to ART must be questioned. Most countries recommend limiting ART to men under 60 years. What is the rationale for this threshold?

OBJECTIVE

This systematic review assesses scientific arguments to establish links between paternal age, male fertility, and offspring health.

MATERIAL AND METHODS

Using the PRISMA guidelines, this systematic review of the literature analyzed 111 articles selected after screening PubMed, ScienceDirect, and Web of Science for articles published between January 1, 1995 and December 31, 2021.

RESULTS

A strong correlation was highlighted between advanced paternal age and a decrease of some sperm parameters (semen volume and sperm motility) and infant morbidity (exponentially increased incidence of achondroplasia and Apert syndrome, and more moderately increased incidence of autism and schizophrenia). The impact of paternal age on pregnancy and fetal aneuploidy rates is more controversial. No association was found with spontaneous abortion rates.

DISCUSSION AND CONCLUSION

The scientific parameters should be explained to older parents undergoing ART. And for countries that discuss a limit on paternal age for access to ART, the debate requires consideration of social and ethical arguments.

Analysing medical predictors for the outcome of infertility treatment: a 5-year follow-up survey

PURPOSE

For many couples, bearing children is a common life goal; however it cannot always be fulfilled. Undergoing infertility treatment does not always guarantee pregnancies and live births. Couples experience miscarriages and even discontinue infertility treatment. Significant medical predictors for the outcome of infertility treatment have yet to be fully identified.

METHODS

To further our understanding, a cross-sectional 5-year follow-up survey was undertaken, in which 95 women and 82 men that have been treated at the Women's Hospital of Heidelberg University participated. Binary logistic regressions, parametric and non-parametric methods were used for our sample to determine the relevance of biological (infertility diagnoses, maternal and paternal age) and lifestyle factors (smoking, drinking, over- and underweight) on the outcome of infertility treatment (clinical pregnancy, live birth, miscarriage, dropout rate). In addition, chi-square tests were used to examine differences in the outcome depending on the number of risk factors being present.

RESULTS

In the binary logistic regression models for clinical pregnancies, live births and drop outs were statistically significant only for the maternal age, whereas the maternal and paternal BMI, smoking, infertility diagnoses and infections showed no significant predicting effect on any of the outcome variables. A correlation between the number of risk factors and the outcome of infertility treatment could not be excluded.

CONCLUSION

The results confirm that maternal age has an effect on infertility treatment, whereas the relevance of other possible medical predictors remains unclear. Further large-scale studies should be considered to increase our knowledge on their predictive power.

Beyond body mass index: a synthesis of lifestyle factors that may influence in vitro fertilisation outcomes

There are several lifestyle factors that are thought to potentially impact in vitro fertilisation outcomes, including body mass index, smoking, alcohol consumption, caffeine, dietary patterns and physical activity. Eligibility criteria for in vitro fertilisation in England often require individuals to be non-smokers, drug free and have a body mass index <30kg/m2. Some researchers have questioned the scientific and ethical basis for the use of body mass index thresholds in fertility treatment, citing evidence that other factors may have a greater effect on the chance of success of in vitro fertilisation. This article aims to briefly synthesise the current evidence on how other factors such as smoking, alcohol, recreational drugs, smoking, caffeine, dietary patterns and physical activity may impact in vitro fertilisation outcomes.

Aging induced testicular damage: analyzing the ameliorative potential of Mucuna pruriens seed extract

Mucuna pruriens Linn. (M. pruriens), a leguminous plant, was used extensively in Ayurveda, to treat male-related infertility. Previous studies have demonstrated antioxidant, androgenic, aphrodisiac, and spermatogenic properties of M. pruriens seed extract. Surprisingly, the biological activities of M. pruriens on aging-induced pathological changes in the testis microenvironment have never been explored and the present study was focused on the testing therapeutic efficacy of M. pruriens on aged rat testis. Male Wistar albino rats were grouped as; adult (3 months), aged (24 months), aged + M. pruriens and adult + M. pruriens (N = 6/group). The extract was administrated at a dose of 200 mg/kg body weight (dosage determined in our previous study) daily by gavage for 60 days. The total and free testosterone, FSH and LH levels were considerably increased in aged + M. pruriens. The diameter & volume of the seminiferous tubules, the height & volume of the epithelium, and the number of Leydig cells number were significantly decreased in aged rat testis, concomitantly connective tissue proportion was increased compared to adult rats. The seminiferous epithelium indicates significant rejuvenation or restoration of spermatogenic cells in aged + M. pruriens rat testis. The highlighting observations in aged + M. pruriens was increased in the following parameters i.e., tubular diameter (25%), number of tubules (35%), epithelial height (25%) & volume (20%), and number of Leydig cells (35%) when compared to untreated aged rat testis. The TNFα, NF-κB, cytochrome c, Caspase-9, Caspase-3, Bcl-2, Bax, PARP iNOS, and inflammatory and apoptotic factors were downregulated in aged + M. pruriens. M. pruriens was able to restore spermatogenesis and enhance the activity of Sertoli cells and Leydig cells and improve the pituitary-gonadal axis in aged rat testis and observations indicate the therapeutic activity of M. pruriens in aged rat testis.

Age-related elevation of O-GlcNAc causes meiotic arrest in male mice

In recent years, the postponement of childbearing has become a critical social issue. Male fertility is negatively associated with age because of testis aging. Spermatogenesis is impaired with age, but the molecular mechanism remains unknown. The dynamic posttranslational modification O-linked N-acetylglucosamine (O-GlcNAc), which is a type of monosaccharide modification, has been shown to drive the process of aging in various systems, but it has not yet been investigated in the testis and male reproductive aging. Thus, this study aims to investigate the alteration of O-GlcNAc with aging and explore the role of O-GlcNAc in spermatogenesis. Here, we demonstrate that the decline in spermatogenesis in aged mice is associated with elevation of O-GlcNAc. O-GlcNAc is specifically localized in differentiating spermatogonia and spermatocytes, indicating its crucial role in meiotic initiation and progression. Mimicking the age-related elevation of O-GlcNAc in young mice by disabling O-GlcNAcase (OGA) using the chemical inhibitor Thiamet-G can recapitulate the impairment of spermatogenesis in aged mice. Mechanistically, the elevation of O-GlcNAc in the testis leads to meiotic pachytene arrest due to defects in synapsis and recombination. Furthermore, decreasing O-GlcNAc in aged testes using an O-GlcNAc transferase (OGT) inhibitor can partially rescue the age-related impairment of spermatogenesis. Our results highlight that O-GlcNAc, as a novel posttranslational modification, participates in meiotic progression and drives the impairment of spermatogenesis during aging.

Impact of Advanced Paternal Age on Fertility and Risks of Genetic Disorders in Offspring

The average age of fathers at first pregnancy has risen significantly over the last decade owing to various variables, including a longer life expectancy, more access to contraception, later marriage, and other factors. As has been proven in several studies, women over 35 years of age have an increased risk of infertility, pregnancy problems, spontaneous abortion, congenital malformations, and postnatal issues. There are varying opinions on whether a father's age affects the quality of his sperm or his ability to father a child. First, there is no single accepted definition of old age in a father. Second, much research has reported contradictory findings in the literature, particularly concerning the most frequently examined criteria. Increasing evidence suggests that the father's age contributes to his offspring's higher vulnerability to inheritable diseases. Our comprehensive literature evaluation shows a direct correlation between paternal age and decreased sperm quality and testicular function. Genetic abnormalities, such as DNA mutations and chromosomal aneuploidies, and epigenetic modifications, such as the silencing of essential genes, have all been linked to the father's advancing years. Paternal age has been shown to affect reproductive and fertility outcomes, such as the success rate of in vitro fertilisation (IVF), intracytoplasmic sperm injection (ICSI), and premature birth rate. Several diseases, including autism, schizophrenia, bipolar disorders, and paediatric leukaemia, have been linked to the father's advanced years. Therefore, informing infertile couples of the alarming correlations between older fathers and a rise in their offspring's diseases is crucial, so that they can be effectively guided through their reproductive years.

Paternal age impairs in vitro embryo and in vivo fetal development in murine

The association between advanced paternal age and impaired reproductive outcomes is still controversial. Several studies relate decrease in semen quality, impaired embryo/fetal development and offspring health to increased paternal age. However, some retrospective studies observed no alterations on both seminal status and reproductive outcomes in older men. Such inconsistency may be due to the influence of intrinsic and external factors, such as genetics, race, diet, social class, lifestyle and obvious ethical issues that may bias the assessment of reproductive status in humans. The use of the murine model enables prospective study and owes the establishment of homogeneous and controlled groups. This study aimed to evaluate the effect of paternal age on in vitro embryo development at 4.5 day post conception and on in vivo fetal development at 16 days of gestation. Murine females (2–4 months of age) were mated with young (4–6 months of age) or senile (18–24 months of age) males. We observed decreased in vitro cleavage, blastocyst, and embryo development rates; lighter and shorter fetuses in the senile compared to the young group. This study indicated that advanced paternal age negatively impacts subsequent embryo and fetal development.

Klausen T, K. Danielsen A, Thomsen T, Bentin-Ley U, B. Knudsen U, Laursen S, R. Petersen M, Haahr K, Petersen K, Lemmen JG, Hindkjær J, Kirk J, Fedder J, J. Almind G, Hnida C, Troest B, B. Povlsen B, Zedeler A, Gabrielsen A, Larsen T, S. Kesmodel U. Is paternal age associated with transfer day, developmental stage, morphology, and initial hCG-rise of the competent blastocyst leading to live birth? A multicenter cohort study

In this study we investigated whether age of men undergoing assisted reproductive technology (ART) treatment was associated with day of transfer, stage, morphology, and initial hCG-rise of the competent blastocyst leading to a live birth? The design was a multicenter historical cohort study based on exposure (age) and outcome data (blastocyst stage and morphology and initial hCG-rise) from men whose partner underwent single blastocyst transfer resulting in singleton pregnancy/birth. The ART treatments were carried out at sixteen private and university-based public fertility clinics. We included 7246 men and women, who between 2014 and 2018 underwent controlled ovarian stimulation (COS) or Frozen-thawed Embryo Transfer (FET) with a single blastocyst transfer resulting in singleton pregnancy were identified. 4842 men with a partner giving birth were included, by linking data to the Danish Medical Birth Registry. We showed that the adjusted association between paternal age and transfer day in COS treatments was OR 1.06, 95% CI (1.00;1.13). Meaning that for every increase of one year, men had a 6% increased probability that the competent blastocyst was transferred on day 6 compared to day 5. Further we showed that the mean difference in hCG values when comparing paternal age group 30–34, 35–39 and 40–45 with the age group 25–29 in those receiving COS treatment, all showed significantly lower adjusted values for older men. In conclusion we hypothesize that the later transfer (day 6) in female partners of older men may be due to longer time spent by the oocyte to repair fragmented DNA of the sperm cells, which should be a focus of future research in men.

Advanced Paternal Age and Future Generations

Paternal age at conception has been increasing. In this review, we first present the results from the major mammalian animal models used to establish that increasing paternal age does affect progeny outcome. These models provide several major advantages including the possibility to assess multi- transgenerational effects of paternal age on progeny in a relatively short time window. We then present the clinical observations relating advanced paternal age to fertility and effects on offspring with respect to perinatal health, cancer risk, genetic diseases, and neurodevelopmental effects. An overview of the potential mechanism operating in altering germ cells in advanced age is presented. This is followed by an analysis of the current state of management of reproductive risks associated with advanced paternal age. The numerous challenges associated with developing effective, practical strategies to mitigate the impact of advanced paternal age are outlined along with an approach on how to move forward with this important clinical quandary.

Pregnancy Achievement by Medical Assisted Reproduction Is Correlated to the G Protein-Coupled Receptor 30 mRNA Abundance in Human Spermatozoa

Estrogens, specifically 17β-estradiol (E2), play an important role in male health, including male fertility. The G protein-coupled receptor for estrogen 30 (GPR30) is essential for mediating the rapid non-genomic effects of E2 on a variety of testicular cells, including spermatozoa, although its molecular effects remain largely unknown. In this work, we hypothesized that the GPR30 mRNA abundance in spermatozoa could be correlated to sperm quality. Sperm GPR30 mRNA could also be carried into the oocyte, potentially impacting embryo development and the success of a pregnancy. For this study, 81 sperm samples were collected from couples seeking fertility treatment and undergoing medically assisted reproduction treatments (ART), following the World Health Organization guidelines. GPR30 mRNA abundance in spermatozoa was assessed with a quantitative polymerase chain reaction. The resulting data show that there is no correlation between the abundance of the GPR30 transcript with paternal BMI, age, or sperm quality parameters. Interestingly, we observed that higher levels of GPR30 mRNA abundance in spermatozoa were related to the achievement of biochemical pregnancy and clinical pregnancy (p < 0.05) by couples undergoing treatment. These results highlight the role of the sperm’s RNA cargo in offspring development, suggesting that spermatozoa mRNA content can influence ART success.

Association between paternal age and singleton birthweight in frozen embryo transfer cycles

BACKGROUND

Many studies have considered maternal age as a determinant factor for success in assisted reproductive technologies (ART), but the potential role of paternal age on neonatal outcomes has been overlooked. This study aimed to explore the association between paternal age and birthweight in frozen embryo transfer (FET) cycles.

METHODS

This retrospective study involved singleton live births born to women undergoing frozen embryo transfer from January 2013 to December 2017 at a tertiary care center in Shanghai, China. The paternal age was classified into four categories: ≤ 30, 31-35, 36-40, and ≥ 41 years. The group consisting of respondents with paternal age of 31-35 was set as the reference group. Singleton birthweight was the primary outcome measure. Z-scores were calculated according to gestational age and newborn gender on birthweight based on the national birthweight reference. Multivariable linear regression analysis was performed to reveal the relationship between paternal age and newborns' birthweight after considering several potential confounders.

RESULTS

Exactly 9765 women who fulfilled the inclusion criteria were enrolled. No significant difference was found on mean birthweight (P = 0.082) and gestation-adjusted Z-scores (P = 0.569) among paternal age categories. The reference group and the group with aged 36-40 years had the highest mean birthweight and Z-scores, respectively (3350.2 ± 467.8 g, 0.36 ± 1.00). A decline in mean birthweight with paternal age was observed, and the group over 40 years had the lowest value of 3309.4 ± 474.3 g, but the difference was not statistically significant. In multivariate analyses, the adjusted odds of very low birthweight (LBW), LBW, and high birthweight in the reference group did not significantly differ with the three other groups. After correcting several potential confounders, no significant correlation was observed between paternal age and neonatal birthweight (P = 0.289).

CONCLUSION

Paternal age was not associated with mean birthweight and gestational age- and gender-adjusted birthweight (Z-scores) of singletons among women who became pregnant in FET cycles.

The effect of paternal age on intracytoplasmic sperm injection outcome in unexplained infertility

Objective

: To examine the effect of paternal age on intracytoplasmic sperm injection (ICSI) outcomes in unexplained infertility.

Subjects and Methods

: This retrospective study, done at the Hamad Medical Corporation, Doha, Qatar screened infertile couples who underwent ICSI between 2014 and 2019 for the inclusion and exclusion criteria defining 'unexplained infertility'. Couples recruited were allocated into two groups: Group A (paternal age <35 years) and Group B (paternal age ≥35 years). Baseline characteristics, investigations including semen and advanced sperm function tests and ICSI records were compared for primary outcomes such as fertilisation, cleavage, clinical pregnancy, miscarriage and live birth; and secondary outcomes such as semen parameters and advanced sperm functions (DNA fragmentation index and oxidation reduction potential).

Results

: We found that final pregnancy outcomes including clinical pregnancy rate (P = 0.231), live-birth rate (P = 0.143), and miscarriage rates (P = 0.466) were not significantly different between the two age groups. Normal fertilisation (P = 0.01) and cleavage rate after ICSI (P = 0.001) were statistically significant when the age groups were compared. Also, normal sperm morphology was found to be significantly different (P = 0.041).

Conclusions

: Advanced paternal age affects sperm morphology, fertilisation and embryo cleavage in ICSI but does not appear to affect clinical pregnancy, miscarriage or live-birth rates. ICSI appears to be a valid fertility treatment option in advancing paternal age.

Paternal age over 50 years decreases assisted reproductive technology (ART) success: A single UK center retrospective analysis

INTRODUCTION

To study whether paternal age exerts an effect, independent of maternal age, on the outcomes of fresh in vitro fertilization/ intracytoplasmic sperm injection (IVF/ICSI) cycles. Semen quality deteriorates with increasing paternal age; however, there is conflicting evidence for any impact paternal age may have on the outcome of IVF/ICSI. Several retrospective and prospective cohort studies have shown that paternal age increases the miscarriage rate and reduces the live birth rate. Some studies have shown no effect of paternal age on live birth rate or miscarriage rate. Studies involving donor oocytes have tended to show no independent effect of paternal age on assisted reproductive technology (ART) outcomes. The age at which paternal age may exert a significant deleterious effect on outcome is not known and there is no limit to paternal age in IVF/ICSI treatment.

MATERIAL AND METHODS

A single-center retrospective cohort study was carried out at the Centre for Reproductive and Genetic Health, London, UK. Included in the analysis were all couples with primary or secondary infertility undergoing IVF/ICSI cycles in which the male partner produced a fresh semen sample and the cycle proceeded to fresh embryo transfer. All cycles of IVF/ICSI that used donor oocytes-donor sperm, frozen sperm, cycles leading to embryo storage and cycles including preimplantation genetic testing (PGT-A/PGT-M)-were excluded from analysis. The primary outcome was live birth rate and secondary outcomes were clinical pregnancy rate and miscarriage rate. Multivariate logistic regression analysis with live birth as a dependent variable and maternal and paternal age class as independent variables was performed.

RESULTS

During the study period there were 4833 cycles, involving 4271 men, eligible for analysis; 1974/4833 (40.8%, 95% confiene intervals [CI] 39.5-42.2%) cycles resulted in a live birth. A significantly lower proportion of men over 51 years met World Health Organization semen analysis criteria (56/133, [42.1%, 95% CI 34.1-50.6]) compared with men under 51 years of age (2530/4138 [61.1%, 95% CI 60.0-62.6]) (p = 0.001). Both maternal and paternal age were retained in the multivariate model and for all maternal age subgroups the probability of live birth decreased with paternal age over 50 years (odds ratio [OR] 0.674, 95% CI 0.482-0.943) (p = 0.021). Paternal age over 50 years was not an independent predictor of miscarriage (OR 0.678, 95% CI 0.369-1.250) (p = 0.214).

CONCLUSIONS

Paternal age over 50 significantly affects the chance of achieving a live birth following ART. Paternal age does not independently affect the risk of miscarriage following ART. There should be a public health message for men not to delay fatherhood.

Influence of paternal age on assisted reproductive technology cycles and perinatal outcomes

OBJECTIVE

To characterize paternal age among assisted reproductive technology (ART) cycles performed in the United States and to evaluate the influence of paternal age on ART cycles and perinatal outcomes.

DESIGN

Retrospective cohort.

SETTING

Not applicable.

PATIENT(S)

All reported fresh, nondonor, noncancelled in vitro fertilization (IVF) cycles performed in 2017.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

The primary outcomes were intrauterine pregnancy, live birth (≥20 weeks), and miscarriage (<20 weeks) per cycle start and per embryo transfer. The secondary outcomes were full-term live birth (≥37 weeks) among singleton and twin gestations. Modified Poisson regression was performed to estimate associations between paternal age and cycle and perinatal outcomes, overall and stratified by maternal age.

RESULT(S)

Among 77,209 fresh nondonor, noncancelled IVF cycles, the average paternal age was 37.8 ± 6.3 years and the average maternal age was 35.5 ± 4.6 years. Compared with paternal age ≤45 years, paternal age ≥46 years was associated with a lower likelihood of pregnancy per cycle (adjusted risk ratio [aRR] 0.81; 95% confidence interval [CI] 0.76-0.87) and per transfer (aRR 0.85; 95% CI 0.81-0.90), as well as a lower likelihood of live birth per cycle (aRR 0.76; 95% CI 0.72-0.84) and per transfer (aRR 0.82; 95% CI 0.77-0.88) after controlling for maternal age and other confounders. When restricted to women aged <35 years, there were no significant differences in the rates of live birth or miscarriage among couples in which the men were aged ≤45 years compared with those aged ≥46 years.

CONCLUSION(S)

Compared with paternal age ≤45 years, paternal age ≥46 years is associated with a lower likelihood of pregnancy and live birth among couples undergoing IVF. The negative effect of paternal age is most notable among women aged ≥35 years, likely because maternal age is a stronger predictor of ART outcome.

Reproductive aging and telomeres: Are women and men equally affected?

Successful reproduction is very important for individuals and for society. Currently, the human health span and lifespan are the object of intense and productive investigation with great achievements, compared to the last century. However, reproduction span does not progress concomitantly with lifespan. Reproductive organs age, decreasing the levels of sexual hormones, which are protectors of health through their action on several organs of the body. Thus, this is the starting point of the organismal decay and infertility. This starting point is easily detected in women. In men, it goes under the surface, undetected, but it goes, nevertheless. Regarding fertility, aging alters the hormonal equilibrium, decreases the potential of reproductive organs, diminishes the quality of the gametes and worsen the reproductive outcomes. All these events happen at a different pace and affecting different organs in women and men. The question is what molecular pathways are involved in reproductive aging and if there is a possible halting or even reversion of the aging events. Answers to all these points will be explained in the present review.

Mental Health Around the Transition to First Birth: Does Medically Assisted Reproduction Matter?

Previous research has shown that childbearing is associated with short-term improvements in women's subjective well-being but that these effects depend on the timing and quantum of the birth as well as on the parents' education and socioeconomic status. These studies did not address whether and, if so, how this effect varies according to the mode of conception. This represents an important knowledge gap, given that conceptions through medically assisted reproduction (MAR) have been increasing rapidly in recent decades, exceeding 5% of live births in some European countries. Drawing on nine waves (2009/2010-2017/2018) of the UK Household Longitudinal Study, we use distributed fixed-effects linear regression models to examine changes in women's mental health before, during, and after natural and MAR conceptions. The results show that the mental health of women who conceived naturally improved around the time of conception and then gradually returned to baseline levels; comparatively, the mental health of women who conceived through MAR declined in the year before pregnancy and then gradually recovered. The findings also indicate that women's happiness decreased both two years and one year before an MAR conception and then increased above the baseline in the year of pregnancy. We further show that the deterioration in mental health and subjective well-being before an MAR conception affects both partners, which could be part of a longer process in which the partners potentially suffer from stress related not solely to the MAR treatments themselves but also to the experience of subfertility.

Factors predicting clinical outcomes from 494 vitrified oocyte donation cycles at a UK-regulated egg bank

RESEARCH QUESTION

Do donor age, AMH, AFC, BMI and reproductive history predict response to ovarian stimulation? Do donor and recipient clinical markers and embryology parameters predict recipient pregnancy and live birth?

DESIGN

Retrospective cohort study of 494 altruistic oocyte donors aged 18-35 years; 340 were matched to 559 recipients. Predictors of donor total oocyte yield and total mature oocyte yield were identified. Total and mature oocyte number were compared according to stratified donor AMH and age. Donor, recipient and embryology parameters predictive of recipient primary outcomes (clinical pregnancy and live birth) were identified.

RESULTS

Donor age and AMH predicted total oocyte yield (P = 0.030 and P < 0.001)) and total mature oocyte yield (P = 0.011 and P < 0.001). Donors aged 30-35 years with AMH 15-29.9 pmol/l had lower total oocyte yield (P = 0.004) and mature oocyte yield (P < 0.001) than donors aged 18-24 years. Up to an AMH threshold of 39.9 pmol/l, increasing AMH levels predicted higher total oocyte yield (<15 pmol/l versus 15-29.9 pmol/l, P = 0.001; 15-29.9 pmol/l versus 30-39.9 pmol/l, P < 0.001; 30-39.9pmol/l versus ≥ 40 pmol/l, P = 1.0) and mature oocyte yield (<15 pmol/l versus 15-29.9 pmol/l, P = 0.005; 15-29.9 pmol/l versus 30-39.9 pmol/l, P = 0.006; 30-39.9 pmol/l versus ≥40 pmol/l, P = 1.0). In recipients, the rate of transferrable embryos per oocytes received, fertilized and number of embryo transfers needed to achieve the primary outcome were predictors of cumulative clinical pregnancy (P = 0.011, P = 0.017 and P < 0.001) and live birth (P = 0.008, P = 0.012 and P < 0.001) rates. Recipient BMI (P = 0.024) and previous miscarriages (P = 0.045) were predictors of cumulative live birth rate. Donor age 18-22 years was associated with a lower incidence of recipient clinical pregnancy (P = 0.004) and live birth (P = 0.001) after the first embryo transfer versus donor age 23-29 years.

CONCLUSIONS

Donor age and AMH are independent predictors of oocyte yield. Raised recipient BMI and history of miscarriages reduce cumulative live birth rates, which may be increased by selecting donors aged 23-29 years, instead of younger donors.

Effect of male age on pregnancy and neonatal outcomes in the first frozen-thawed embryo transfer cycles of IVF/ICSI treatment

BACKGROUND

The effect of male age on pregnancy outcomes after assisted reproductive technology (ART) treatment shown in the previous literature is controversial. In addition, the influence of male age on neonatal outcomes following ART treatment has less been investigated.

OBJECTIVES

The aim of this study was to evaluate the effect of male age on reproductive and neonatal outcomes in couples following ART treatment.

MATERIALS AND METHODS

A retrospective cohort study was performed in two centers for assisted reproduction from June 2010 to February 2019. A total of 5512 frozen-thawed embryo transfer (FET) cycles were included according to the criteria. The primary outcome measures were pregnancy and neonatal outcomes. Patients were categorized into five groups according to male age (younger than 30, 31-35, 36-40, 41-45, and older than 45), and the group younger than 30 years old was treated as the reference group.

RESULTS

The logistic regression analysis showed that clinical pregnancy and live birth were all no statistic difference among the male age-groups compared with the reference group (p values, 0.743, 0.979, 0.948, 0.28; p values, 0.823, 0.342, 0.817, 0.381, respectively). Furthermore, no significant differences were found in the preterm birth rate, child sex, neonatal malformation, birth weight, and gestational age (p > 0.05). The advanced male age was not associated with a higher risk of adverse neonatal outcomes.

DISCUSSION AND CONCLUSION

This study showed that there were no effects of male age on pregnancy or neonatal outcomes in infertile couples following their first FET cycles when females were younger than 36 years old.

Age-related changes in human conventional semen parameters and sperm chromatin structure assay-defined sperm DNA/chromatin integrity

RESEARCH QUESTION

What are the correlations between male age, traditional semen parameters, sperm DNA fragmentation index (DFI) and high DNA stainability (HDS) in a sufficiently large sample size?

DESIGN

Retrospective cohort study of 18,441 semen samples, with data divided into seven age groups according to male age: ≤25, 26-30, 31-35, 36-40, 41-45, 46-50 and ≥51 years.

RESULTS

Age was negatively correlated with semen volume, total sperm count, motility and HDS, and positively correlated with sperm concentration and DFI (P < 0.001). After 35 years of age, semen volume and total sperm count began to decline. After 30 years of age, motility and HDS decreased consistently. Sperm concentration and DFI increased from 26-30 years of age. DFI was negatively correlated with sperm concentration, total sperm count, motility and normal morphology (P < 0.001) and positively correlated with semen volume and HDS (P < 0.001). HDS was negatively correlated with all parameters (P < 0.001) except semen volume (r = -0.013, P = 0.074) and DFI (r = 0.124, P < 0.001). Patients aged ≥40 years had higher DFI than those aged <40 years in the entire cohort, in the abnormal semen parameters cohort, and in the normal semen parameters cohort (OR 2.145, 2.042, 1.948, respectively, P < 0.001). The ≥40 years age group had a lower HDS than the <40 years age group in the entire cohort and abnormal semen parameters cohort (OR 0.719, 0.677, respectively, P < 0.001).

CONCLUSIONS

Ageing is a negative effector of sperm quantity and quality, and routine sperm parameters have weak but significant correlations with sperm DNA/chromatin integrity.

Effect of senescence on morphological, functional and oxidative features of fresh and cryopreserved canine sperm

The present research aimed to compare the hormonal profile, sperm quality and freezability of young and senile dogs. Dogs were assigned into Young Group (n = 11) and Senile Group (n = 11), additionally divided into Fresh Semen Group and Cryopreserved Semen Group. Males were evaluated for libido score and blood estrogen and testosterone assay. Sperm morphofunctional evaluations were performed based on Computer Assisted Sperm Analysis, morphology, mitochondrial activity, mitochondrial membrane potential, plasma and acrosomal membrane integrity, and DNA fragmentation. Sperm oxidative features were: protein oxidation, lipid peroxidation and production of advanced glycation end-products. Young dogs had higher libido score, sperm velocity average pathway, linearity of motility and mitochondrial activity index and lower percentage of major defects, total defects and proximal cytoplasmic droplet, despite the lack of difference between hormone profile of aged dogs. Fresh semen of senile dogs had increased percentage of spermatozoa with high mitochondrial membrane potential compared to young dogs and to cryopreserved sperm. Cryopreserved semen of young dogs had higher acrosomal membrane integrity compared to the Senile Group. In conclusion, sperm of aged dogs have reduced quality, signaled by higher morphological defects, ultimately altering sperm mitochondrial function and sperm kinetics. Furthermore, spermatozoa from senile dogs are more sensible to cryoinjury.

Advanced paternal age: effects on sperm parameters, assisted reproduction outcomes and offspring health

Many factors, including postponement of marriage, increased life expectancy, and improved success with assisted reproductive technologies have been contributing to increased paternal age in developed nations. This increased average paternal age has led to concerns about adverse effects of advanced paternal age on sperm quality, assisted reproductive outcomes, and the health of the offspring conceived by older fathers. This review discusses the association between advanced paternal age and sperm parameters, assisted reproduction success rates, and offspring health.

Advanced paternal age is associated with an increased risk of spontaneous miscarriage: a systematic review and meta-analysis

BACKGROUND

Although spontaneous miscarriage is the most common complication of human pregnancy, potential contributing factors are not fully understood. Advanced maternal age has long been recognised as a major risk factor for miscarriage, being strongly related with fetal chromosomal abnormalities. The relation between paternal age and the risk of miscarriage is less evident, yet it is biologically plausible that an increasing number of genetic and epigenetic sperm abnormalities in older males may contribute to miscarriage. Previous meta-analyses showed associations between advanced paternal age and a broad spectrum of perinatal and paediatric outcomes. This is the first systematic review and meta-analysis on paternal age and spontaneous miscarriage.

OBJECTIVE AND RATIONALE

The aim of this systematic review and meta-analysis is to evaluate the effect of paternal age on the risk of spontaneous miscarriage.

SEARCH METHODS

PubMed, Embase and Cochrane databases were searched to identify relevant studies up to August 2019. The following free text and MeSH terms were used: paternal age, father's age, male age, husband's age, spontaneous abortion, spontaneous miscarriage, abortion, miscarriage, pregnancy loss, fetal loss and fetal death. PRISMA guidelines for systematic reviews and meta-analysis were followed. Original research articles in English language addressing the relation between paternal age and spontaneous miscarriage were included. Exclusion criteria were studies that solely focused on pregnancy outcomes following artificial reproductive technology (ART) and studies that did not adjust their effect estimates for at least maternal age. Risk of bias was qualitatively described for three domains: bias due to confounding, information bias and selection bias.

OUTCOMES

The search resulted in 975 original articles. Ten studies met the inclusion criteria and were included in the qualitative synthesis. Nine of these studies were included in the quantitative synthesis (meta-analysis). Advanced paternal age was found to be associated with an increased risk of miscarriage. Pooled risk estimates for miscarriage for age categories 30-34, 35-39, 40-44 and ≥45 years of age were 1.04 (95% CI 0.90, 1.21), 1.15 (0.92, 1.43), 1.23 (1.06, 1.43) and 1.43 (1.13, 1.81) respectively (reference category 25-29 years). A second meta-analysis was performed for the subgroup of studies investigating first trimester miscarriage. This showed similar pooled risk estimates for the first three age categories and a slightly higher pooled risk estimate for age category ≥45 years (1.74; 95% CI 1.26, 2.41).

WIDER IMPLICATIONS

Over the last decades, childbearing at later ages has become more common. It is known that frequencies of adverse reproductive outcomes, including spontaneous miscarriage, are higher in women with advanced age. We show that advanced paternal age is also associated with an increased risk of spontaneous miscarriage. Although the paternal age effect is less pronounced than that observed with advanced maternal age and residual confounding by maternal age cannot be excluded, it may have implications for preconception counselling of couples comprising an older aged male.

Predictors of surgical sperm retrieval in non-obstructive azoospermia: summary of current literature

Intracytoplasmic sperm injection (ICSI), combined with surgical sperm retrieval (SR) techniques, is the sole option for patients with non-obstructive azoospermia to achieve fertility; however, with suboptimal results. Given the variability in clinical presentation, the potential role of factors that can predict the likelihood of successful testicular SR needs to be clarified. This article summarizes the current evidence concerning the variables predicting SR success in non-obstructive azoospermic patients with spermatogenic failure. For this, we used 60 articles, including 46 original papers and six meta-analyses. Clinical and laboratory factors, as well as adjuvant therapies and surgical retrieval methods, were the factors most commonly investigated. We found that Klinefelter syndrome, Y chromosome microdeletions in regions AZFa/b, and Sertoli cell-only histopathology were associated with reduced SR success. By contrast, testis volume > 12.5 ml, history of cryptorchidism, use of micro-TESE as the sperm retrieval method, and adjuvant therapy were associated with improved SR success. None of the predictors, alone or combined, provide definitive information about the chances of harvesting sperm in men with non-obstructive azoospermia, except for Y chromosome microdeletions in regions AZFa/b. In the latter, SR success is virtually nil. We conclude that SR outcomes in men with non-obstructive azoospermia are difficult to predict based on the existing variables. Although several predictors can be used for patient counseling, their clinical value is limited to either ensure SR success or discourage reproductive urologists from recommending SR to men with non-obstructive azoospermia seeking fertility. A notable exception includes the deletions involving the regions AZFa and/or AZFb of the Y chromosome; the affected patients should be counseled against undergoing SR.

Paternal Age Does Not Influence the Outcomes of Assisted Reproduction in Donor Oocyte Cycles

Purpose: To study effect of paternal age on pregnancy outcomes of intracytoplasmic sperm injections (ICSI).

Methods: The present study is a retrospective analysis of 153 ICSI cycles on donor oocytes. The effect of paternal age on fertilization rates, implantation rates, total pregnancy rates, number of miscarriages and live births were analyzed.

Results: 1422 donor oocytes were injected with sperm from 153 men. Linear regression analysis revealed no association between paternal age (28-54 years) and fertilization rate. No association was found between the embryo quality and paternal age. Of the 359 embryos transferred, linear regression analysis revealed no association between paternal age and implantation rate. After correcting for maternal age, binary logistic regression analysis revealed no association between total pregnancy rates (B = 0.943, CI 0.861-1.033, P = 0.205), live birth rates (B = 1.018, CI 0.896-1.158, P = 0.562) and miscarriage rates (B = 0.944, CI 0.866-1.029, P = 0.193) and paternal age.

Conclusion: Paternal age does not seem to influence outcomes in assisted reproduction.

Effect of paternal age on treatment outcomes in couples undergoing assisted reproductive technology for non-male factor infertility: a retrospective analysis of 809 cycles

Background

Worldwide, there is an increase in uptake of assisted reproductive technology (ART) treatment. The impact of paternal age on ART outcomes is unclear. In view of the conflicting results reported by studies evaluating effect of paternal age on ART outcomes, we planned a study to investigate the impact of advanced paternal age in couples undergoing ART for non-male factor infertility. We conducted a retrospective cohort study at a university-level teaching hospital in South India. All couples who underwent ART for non-male factor infertility were included. The couples were divided into two groups based on the age of the male partner. Group I included couples with male partner’s age less than 40 years, taken as reference group. Group II included couples with male partners age more than or equal to 40 years. The primary outcome was live birth rate. Secondary outcomes included clinical pregnancy, miscarriage, fertilization, embryo development, and blastulation rates.

Results

A total of 809 cycles were included for the study. Following exclusion of 39 cycles, 770 cycles were analyzed for outcomes. Group I comprised of 556 (72%) cycles and group II comprised of 214 (28%) cycles. There was no significant difference in live birth rate per embryo transfer between groups I and II (31.8% vs. 29.4%; odds ratio, OR, 0.89; 95% CI 0.63 to 1.26). After adjustment for potential confounders, the live birth rate did not differ significantly (adjusted odds ratio, aOR, 1.10; 95% CI 0.74 to 1.65). The clinical pregnancy (39.4% vs. 36%; aOR 1.06; 95% CI 0.72 to 1.56) and the miscarriage rates (18.3% vs. 15.6%; aOR 0.73; 95% CI 0.32 to 1.66) were also similar between the two groups. There was significant decrease in the blastulation rate (36.8% vs. 32.1%; P 0.002) in the advanced paternal age group as compared to the reference group.

Conclusion

The current study suggests that in couples undergoing ART for non-male factor, there is no detrimental effect of increasing paternal age on treatment outcomes.

The age of the bull influences the transcriptome and epigenome of blastocysts produced by IVF

Genetic selection for the best suited offspring drives the dairy industry to use young genitors and assisted reproductive technologies (ART) to reduce generation intervals. However, sperm samples collected from peri-pubertal bulls have lower counts and quality compared to samples from adult bulls. Moreover, our previous study identified differentially methylated regions (DMRs) in sperms from early-, peri- and post-pubertal bulls. The aim of this study was to further investigate the impacts of paternal age on early embryos. To achieve this, we evaluated the transcriptome and the epigenome of bovine blastocysts generated from spermatozoa of bulls at 10, 12, and 16 months of age and used in vitro fertilization (IVF) of oocytes recovered from the same adult cows. A total of 259 probes were differentially expressed and 6953 probes were differentially methylated in the 10- vs 16-month and the 12- vs 16-month groups. Ingenuity Pathway Analysis (IPA) of transcriptomic data demonstrated that energy-related pathways such as oxidative phosphorylation, EIF2 signaling, and mitochondrial dysfunction were affected the most by the age of the bull. Meanwhile, IPA analysis of the epigenome revealed that protein kinase A signaling, RAR activation, and other pathways were influenced by paternal age. Overall, we showed that the bull's age mainly influenced metabolism-related pathways in blastocysts, and this could therefore impact subsequent development.

Male ageing is negatively associated with the chance of live birth in IVF/ICSI cycles for idiopathic infertility

STUDY QUESTION

Is male age associated with the clinical outcomes of IVF/ICSI cycles for idiopathic infertility after adjustment for female age?

SUMMARY ANSWER

Male ageing is negatively associated with clinical IVF/ICSI outcomes in couples with idiopathic infertility independent of female age.

WHAT IS KNOWN ALREADY

The effect of male age on the outcomes of infertility treatments is controversial and poorly explored. In contrast, fertility is known to decline significantly with female age beyond the mid-30s, and reduced oocyte quality plays an important role. The negative effect of male age on sperm quality is largely associated with an increasing susceptibility to sperm DNA damage. Although increasing maternal age has been linked with poorer oocyte quality, studies on the effect of male age have disregarded the need to control for female age making it difficult to define clearly the role of male age in infertile couples.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study analysed 2425 cycles of couples with idiopathic infertility selected from a total of 24 411 IVF/ICSI cycles performed at Monash IVF in Australia between 1992 and 2017. The primary outcome was live birth and secondary outcomes were clinical pregnancy and miscarriage.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Couples with primary/secondary infertility who underwent IVF/ICSI cycles with male partners classified as normozoospermic were selected (inclusion criteria). Couples in which the female partner had endometriosis, tubal factors, polycystic ovarian syndrome, ovarian hyperstimulation syndrome, poor responders (≤3 mature oocytes retrieved) and couples with more than 15 cumulus oocyte complexes retrieved or who used cryopreserved gametes were excluded. Binary logistic multilevel modelling was used to identify the effect of male age and female age on clinical outcomes after controlling for confounding factors. Male age and female age were examined as continuous and categorical (male age: &lt;40, 40–44, 45–49, 50–54, ≥55; female age:&lt;30, 30–34, 35–39, ≥40) predictors.

MAIN RESULTS AND THE ROLE OF CHANCE

There was a negative effect of male age and female age on live birth as odds ratios (OR) with 95% CI for each additional year of age (OR-male age: 0.96 [0.94–0.98]; OR-female age: 0.90 [0.88–0.93] P &lt; 0.001). Potential interactions with male age such as type of treatment (IVF/ICSI), embryo transfer day (Day 3/Day 5) and female age did not have significant associations with outcomes (P &gt; 0.05). Secondary outcomes showed a significant reduction in the odds of clinical pregnancy (OR-male age: 0.97 [0.96–0.99]; OR-female age: 0.92 [0.89–0.94] P &lt; 0.001) and an increase in the odds of miscarriage with older age: male age (OR: 1.05 [1.01–1.08]; P = 0.002); female age (OR: 1.11 [1.05–1.18]; P &lt; 0.001). Worse outcomes were associated with more cycles (clinical pregnancy-OR: 0.96 [0.93–0.99] P = 0.03; live birth-OR: 0.96 [0.92–0.99] P = 0.023) while more inseminated oocytes were associated with better outcomes (clinical pregnancy-OR: 1.06 [1.03–1.06] P &lt; 0.001; live birth-OR: 1.07 [1.04–1.11] P &lt; 0.001). Analyses for age categories showed a gradual worsening of clinical outcomes with increasing male age, with a significantly worse live birth and clinical pregnancy outcomes in males aged older than 50 years compared to males younger than 40 years (P &lt; 0.05).

LIMITATIONS, REASONS FOR CAUTION

This study is limited to the information on confounding factors included. The study may also be limited in its generalizability to a wider population due the strict selection criteria. Age as a category could potentially result in residual confounding due to categorizing a continuous variable.

WIDER IMPLICATIONS OF THE FINDINGS

This study provides information for counselling of couples with idiopathic infertility.

STUDY FUNDING/COMPETING INTEREST(S)

Funded by the Education Program in Reproduction and Development, Department of Obstetrics and Gynaecology, Monash University. None of the authors has any conflict of interest to report.

TRIAL REGISTRATION NUMBER

N/A.

Incidence of high sperm DNA fragmentation in a targeted population of subfertile men

Sperm DNA integrity is important for fertility, however the incidence of high levels of DNA fragmentation (DNA fragmentation index (DFI) >30%) is not well described. In 2011, our clinics implemented guidelines for sperm DNA fragmentation (SDF) testing based on risk factors using the sperm chromatin structure assay (SCSA). The aim of this retrospective study is to characterise SDF and associated factors (age, semen parameters, smoking status and BMI) for sub-fertile males (n = 1082) and sperm donors (n = 234). The average DFI was 12.1 ± 9.8%. The distribution of men with low, moderate and high SDF (<15, 15-30 and >30%) was 74.8%, 19.4% and 5.8%, respectively. Men with high DFI were older (45 ± 9.5 vs 38 ± 6.7) and had lower percentage of motile sperm (38.8 ± 16.1% vs 55.3 ± 15.8%) than men with normal DFI. Over 17% of the men in the quartile with the highest age and lowest motility had a high DFI (>30%), compared to a high DFI rate of 2-4% for the other 3 quartiles. Repeat testing following lifestyle interventions was available for 29 couples where the men had high initial DFI (35 ± 9.5%). Of these men, 71.4% had a decrease of DFI into the moderate or low range. This study shows that SDF testing can be targeted based on age and sperm motility, thereby reducing unnecessary testing. Furthermore, we provide evidence that lifestyle modifications can reduce DNA fragmentation in men with high DFI.

Sperm origins and concentration do not impact the clinical outcomes in intracytoplasmic sperm injection cycles

In the present study, we evaluated the impact of sperm origins and concentration on the clinical outcomes of intracytoplasmic sperm injection (ICSI) cycles. A total of 1201 ICSI cycles were retrospectively analyzed for male azoospermia or oligozoospermia between January 2015 and December 2015 in the Peking University Third Hospital. Patients were divided into three groups (Group 1 vs Group 2/3; surgically extracted sperm vs ejaculated sperms): Group 1 included 343 ICSI cycles and Group 2 analyzed 388 cycles on semen with sperm concentration <5 × 10⁶ ml⁻¹ (severe oligozoospermia group). Group 3 included 470 cycles with sperm concentration between 5 × 10⁶ ml⁻¹ and 15 × 10⁶ ml⁻¹ (mild oligozoospermia group). Fertilization rates, clinical pregnancy rates, and live birth rates were analyzed and compared among groups of different semen origins and concentrations on the oocyte retrieval day. Group 2 showed a lower fertilization rate than Group 3 (62.9% ± 21.6% vs 66.8% ± 22.1%,P < 0.05). There were no statistically significant differences in clinical pregnancy rate per transfer (51.3%, 46.7%, and 50.0%, respectively), live birth rate per transfer (44.4%, 40.9%, and 41.4%, respectively), accumulative live birth rate (58.3%, 51.0%, and 52.1%, respectively), twin birth rate (18.4%, 10.6%, and 12.6%, respectively), and birth defects rate (0, 0.3%, and 0.2%, respectively) among three groups. The results of this study indicated that sperm origins and concentration do not impact the clinical outcomes in ICSI cycles.

Associations of sperm mitochondrial DNA copy number and deletion rate with fertilization and embryo development in a clinical setting

STUDY QUESTION

Are sperm mitochondrial DNA copy number (mtDNAcn) and deletion rate (mtDNAdel) associated with odds of fertilization and high embryo quality at Days 3 and 5?

SUMMARY ANSWER

Higher sperm mtDNAcn and mtDNAdel were associated with lower odds of high quality Day 3 embryos and transfer quality Day 5 embryos, both of which were primarily driven by lowered odds of fertilization.

WHAT IS KNOWN ALREADY

Sperm mtDNAcn and mtDNAdel have been previously associated with poor semen parameters and clinical male infertility. One prior study has shown that mtDNAdel is associated with lower fertilization rates. However, it is unknown whether these characteristics are linked with ART outcomes.

STUDY DESIGN, SIZE, DURATION

This prospective observational study included 119 sperm samples collected from men undergoing ART in Western Massachusetts. ART outcomes were observed through to Day 5 post-insemination.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

As part of the Sperm Environmental Epigenetics and Development Study (SEEDS), 119 sperm samples were collected from men undergoing ART in Western Massachusetts. Sperm mtDNAcn and mtDNAdel were measured via triplex probe-based qPCR. Fertilization, Day 3 embryo quality and Day 5 embryo quality measures were fitted with mtDNAcn and mtDNAdel using generalized estimating equations.

MAIN RESULTS AND THE ROLE OF CHANCE

After adjusting for male age and measurement batches, higher sperm mtDNAcn and mtDNAdel were associated with lower odds of fertilization (P = 0.01 and P < 0.01), high quality Day 3 embryos (P = 0.02 for both) and transfer quality Day 5 embryos (P = 0.01 and P = 0.09). However, the associations of mtDNAcn and mtDNAdel with Day 3 high quality status and Day 5 transfer quality status were attenuated in models restricted to fertilized oocytes. Sperm mtDNAcn and mtDNAdel remained statistically significant in models adjusted for both male age and semen parameters, although models including both mtDNA markers generally favoured mtDNAdel.

LIMITATIONS, REASONS FOR CAUTION

Our sample only included oocytes and embryos from 119 couples and thus large diverse cohorts are necessary to confirm the association of sperm mtDNA biomarkers with embryo development.

WIDER IMPLICATIONS OF THE FINDINGS

To our knowledge, our study is the first to assess the associations of sperm mtDNAcn and mtDNAdel with fertilization and embryo quality. The biological mechanism(s) underlying these associations are unknown. Multivariable models suggest that sperm mtDNAcn and mtDNAdel provide discrimination independent of age and semen parameters; therefore, future investigation of the utility of sperm mtDNA as a biomarker for ART outcomes is warranted.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by Grant (K22-ES023085) from the National Institute of Environmental Health Sciences. The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

The effect of paternal age on semen quality and fertilization outcome in men with normal sperm DNA compaction, reactive oxygen species, and total antioxidant capacity levels

OBJECTIVE

Studies showed a decrease of the semen analysis parameters and an increase in the average age of first-time fathers over the past several decades. The aim of the present study was to assess the influence of paternal age on semen quality and fertilization outcomes in men with normal sperm DNA fragmentation and chromatin maturation index (DFI and CMI), reactive oxygen species (ROS), and total antioxidant capacity (TAC) levels.

MATERIAL AND METHODS

The study was performed on 70 men with their wife's age ≤38 years and normal sperm DFI, CMI, ROS, and TAC levels. None of the couples had a history of genital inflammation, chronic diseases, endocrine abnormality, chromosomal aberrations, Y chromosome microdeletion, azoospermia, and leukocytospermia. These men were separated into 2 groups according to their age (group A: age <45 years and group B: age ≥45 years). Semen analysis and fertilization outcome after using the intracytoplasmic sperm injection were assessed in both groups.

RESULT

Sperm concentration showed a significant reduction in group B (p=0.04). Although semen volume, sperm normal morphology, and progressive motility were decreased in group B, the reduction was not significant when compared with group A (p=0.09, p=0.47, and p=0.77, respectively). In addition, the differences of embryo quality with grades A, B, and C and 8-cell embryo formation were not statistically significant between the 2 groups.

CONCLUSION

These results demonstrated that in men with normal sperm DFI, CMI, ROS, and TAC levels, there were no significant changes in semen parameters and fertilization outcomes with an increasing age.

Impact of age, clinical conditions, and lifestyle on routine semen parameters and sperm kinematics

OBJECTIVE

To assess the impact of aging on routine semen and computer-assisted sperm analysis (CASA) motility parameters according to the current World Health Organization guidelines; and to evaluate the effect of obesity and lifestyle (alcohol consumption, cigarette smoking) in older men's semen.

DESIGN

Blind cross-sectional study.

SETTING

Research laboratory and andrology and reproduction laboratory.

PATIENT(S)

A population of 11,706 men.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Semen analysis: routine (semen volume, sperm concentration and count, motility, vitality, morphology, hypo-osmotic swelling test, round and peroxidase-positive cell concentration) and CASA (straight-line velocity, curvilinear velocity, average path velocity, linearity, straightness, beat cross frequency, wobble, amplitude of lateral head displacement, and mean angular displacement) parameters; and body mass index.

RESULT(S)

A negative correlation was found between age and routine semen parameters: volume, sperm count, motility, vitality, total motile spermatozoa and normal-motile spermatozoa, round cell concentration, and hypo-osmotic swelling test values. Several CASA variables (straight-line velocity, curvilinear velocity, average path velocity, beat cross frequency, amplitude of lateral head displacement, and mean angular displacement) were also negatively affected. Using 40 years as a cut-off value, significant differences in most parameters correlated to age. In a selected subpopulation of men unexposed to known fertility-compromising factors, the same evaluations were performed, finding some parameters still decreased. Although obesity exerted a significant deleterious effect on older patients' semen quality, alcohol consumption and cigarette smoking mildly affected it.

CONCLUSION(S)

Male aging, with the contribution of unhealthy conditions, are paramount effectors of sperm quality deterioration.

The influence of obesity, smoking, and serum follicular stimulating hormone in azoospermic patients on testicular sperm extraction-intra cytoplasmic sperm injection outcomes: A retrospective cohort study

To examine the effect of serum follicle-stimulating hormone (sFSH) level, body-mass index (BMI) and smoking on Testicular Sperm Extraction-Intracytoplasmic Sperm Injection (TESE-ICSI), and pregnancy outcomes.In this retrospective study, data were extracted from files of 52 azoospermic men who underwent TESE and in-vitro fertilization (IVF)-ICSI in our IVF unit. Demographic information, treatment cycle follow-up and pregnancy outcomes were collected.Fifty-two patients underwent 79 TESE due to azoospermia in 143 IVF cycles. Smoking was found to significantly affect sperm motility in TESE specimens before freezing (45.5% vs 14.8%; P <.001); however, this finding did not influence the pregnancy rate. Male FSH was inversely correlated with testicle volume (r = -0.595, P <.0001). Body weight did not affect semen parameters after TESE or ICSI outcomes.Among azoospermic patients with extremely poor sperm quality, male BMI, male FSH or smoking did not have an adverse effect sperm parameters or pregnancy and delivery rates.

Sperm epigenetics and aging

Advanced paternal age has very real consequences in fertility, embryogenesis, and even offspring health. Specifically, advanced paternal age has been linked to delayed time to pregnancy and in some studies even appears to be linked to a decreased likelihood of achieving a pregnancy. Epidemiological and animal model evidence also suggests that the offspring of older fathers are at an elevated risk for neuropsychiatric disease. For these reasons it is essential that we have a comprehensive understanding of what actually occurs in the gametes of the aging male. Available data suggest that there are very clear patterns of aging in the sperm epigenome that can be directly detected in DNA methylation patterns. Importantly, these alterations are so consistent that a predictive model has been successfully generated to predict an individual's age based only on sperm DNA methylation signatures. Because this metric is the most direct way to detect aging in sperm, it is logical that these signatures may offer predictive value for the offspring abnormalities that are also correlated with advanced paternal age and as such may offer a unique opportunity to generate diagnostic tools that can identify personalized risks for each couple hoping to achieve a pregnancy. While a great deal of work still needs to be performed to understand the real diagnostic utility of sperm epigenetic marks, the potential is real and warrants further investigation particularly in the context of advanced paternal age.

Just relax and you'll get pregnant? Meta-analysis examining women's emotional distress and the outcome of assisted reproductive technology

RATIONALE

Couples worldwide are seeking treatment for infertility in growing numbers. Both infertility and its treatment are stressful experiences that generate considerable emotional distress. There is speculation that women's distress is associated with poorer likelihood of pregnancy via assisted reproductive technology (ART) and plausible psychobiological mechanisms bolster this association, although prior reviews of existing evidence find little support. A rigorous, comprehensive, and up to date analysis of research on the association of women's distress with ART outcomes is imperative.

OBJECTIVE

We systematically searched for and analyzed evidence regarding the association of women's distress before and during treatment with the likelihood of treatment success via ART.

METHOD

Meta-analysis using a random-effects model was conducted on prospective studies (k = 20) that compared levels of anxiety, depressive symptoms, or perceived stress before or during ART treatment in women who achieved successful pregnancy outcomes versus those who did not (total N = 4308).

RESULTS

Anxiety, depressive symptoms, or perceived stress pre-treatment, and anxiety or depressive symptoms during treatment, were not associated with less favorable ART outcomes. Prior treatment experience, age, and duration of infertility were not significant moderators of these associations. No eligible studies examined perceived stress during treatment.

CONCLUSION

Results cast doubt on the belief that distress impedes the success of infertility treatment, offering hope and optimism to the many women who feel emotionally responsible for the outcome of ART and informing the evidence-based practices of their health-care providers. We also identify specific areas and research methods needed to corroborate and extend study conclusions, including study of factors that elevate or attenuate distress in women undergoing infertility treatment.

Advanced Paternal Age Affects Sperm Count and Anogenital Distance in Mouse Offspring

In Western society, couples increasingly delay parenthood until later in life. Overall, studies have focused on the reproductive performance of older parents or the impact of advanced maternal age on pregnancy outcomes, but few studies have examined how advanced paternal age (APA) affects offspring health. The aim of this study was to investigate the impact of increasing paternal age on offspring reproductive performance and long-term metabolic health in a mouse model. Here, the same adult B6D2F1/J male mice were mated at 4, 12, and 18 months of age with 6- to 10-week-old naturally cycling CF1 females to generate 3 offspring cohorts conceived at increasing paternal ages PA4, PA12, and PA18. The offspring resulting from mating the same fathers at different ages (n = 20 per age; 10 males and 10 females) were maintained up to 20 weeks of age and morphometric parameters, growth curve, and glucose tolerance were measured. We found that increasing paternal age was associated with a trend toward longer time to conception. Litter sizes were not significantly different. Reassuringly, metabolic parameters and growth curve were not different in the 3 cohorts of offspring. Most importantly, increased paternal age (PA4 vs PA18) was associated with a statistically significant decrease in sperm concentration, sperm motility, and anogenital distance in offspring. These changes raise concerns about the potential impact of APA on the reproductive fitness in males of the next generation.