Increasing paternal age is associated with delayed conception in a large population of fertile couples: evidence for declining fecundity in older men. The ALSPAC Study Team (Avon Longitudinal Study of Pregnancy and Childhood)

Relationship between male aging and semen quality: a retrospective study on over 2500 men

PURPOSE

We aimed to evaluate whether and to what extent an association exists between male aging and worsening of semen parameters and to determine whether a threshold age can be identified above which the decline in semen quality becomes statistically significant.

METHODS

2612 men (age: 16-56 years) attending an andrology outpatient clinic for semen analysis and clinical evaluation were studied. Semen analyses were performed according to the ongoing WHO-recommended procedures. Total motile count (TMC) and total progressive motile count (TPMC) were calculated by multiplying total sperm number by total motility and progressive motility, respectively.

RESULTS

Significant negative correlations were found between age and total motility (r = - 0.131, p < 0.0001), progressive motility (r = - 0.112, p < 0.0001), TPMC (r = - 0.042, p = 0.037), and normal sperm morphology (r = - 0.053, p = 0.007). All these associations persisted in multivariate regression models adjusted for abstinence time, smoking, history of male accessory gland infections, varicocele and the year in which semen analysis was performed. When comparisons were performed among quartiles of increasing age, the fourth quartile, corresponding to the age group > 40 years, was associated with a significant decrease in total and progressive motility. An earlier decline in the TPMC and percentage of normal forms was also observed.

CONCLUSION

Advancing male age exhibits an independent association with a decrease in the percentage of motile and morphologically normal spermatozoa, with greater evidence from the age of > 40 years. Further studies are warranted to elucidate the mechanisms and clinical reflections of these associations.

Time to pregnancy and life expectancy: a cohort study of 18 796 pregnant couples

STUDY QUESTION

Is fecundity, measured as time to pregnancy (TTP), associated with mortality in parents?

SUMMARY ANSWER

Prolonged TTP is associated with increased mortality in both mothers and fathers in a dose-response manner.

WHAT IS KNOWN ALREADY

Several studies have linked both male and female fecundity to mortality. In women, infertility has been linked to several diseases, but studies suggest that the underlying conditions, rather than infertility, increase mortality.

STUDY DESIGN, SIZE, DURATION

A prospective cohort study was carried out on 18 796 pregnant couples, in which the pregnant women attended prophylactic antenatal care between 1973 and 1987 at a primary and tertiary care unit. The couples were followed in Danish mortality registers from their child's birth date until death or until 2018. The follow-up period was up to 47 years, and there was complete follow-up until death, emigration or end of study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

At the first antenatal visit, the pregnant women were asked to report the time to the current pregnancy. Inclusion was restricted to the first pregnancy, and TTP was categorised into <12 months, ≥12 months, not planned, and not available. In sub-analyses, TTP ≥12 was further categorized into 12-35, 36-60, and >60 months. Information for parents was linked to several Danish nationwide health registries. Survival analysis was used to estimate the hazard ratios (HRs) with a 95% CI for survival and adjusted for age at the first attempt to become pregnant, year of birth, socioeconomic status, mother's smoking during pregnancy, and mother's BMI.

MAIN RESULTS AND THE ROLE OF CHANCE

Mothers and fathers with TTP >60 months survived, respectively, 3.5 (95% CI: 2.6-4.3) and 2.7 (95% CI: 1.8-3.7) years shorter than parents with a TTP <12 months. The mortality was higher for fathers (HR: 1.21, 95% CI: 1.09-1.34) and mothers (HR: 1.29, 95% CI: 1.12-1.49) with TTP ≥12 months compared to parents with TTP <12 months. The risk of all-cause mortality during the study period increased in a dose-response manner with the highest adjusted HR of 1.98 (95% CI: 1.62-2.41) for fathers and 2.03 (95% CI: 1.56-2.63) for mothers with TTP >60 months. Prolonged TTP was associated with several different causes of death in both fathers and mothers, indicating that the underlying causes of the relation between fecundity and survival may be multi-factorial.

LIMITATIONS, REASONS FOR CAUTION

A limitation is that fecundity is measured using a pregnancy-based approach. Thus, the cohort is conditioned on fertility success and excludes sterile couples, unsuccessful attempts and spontaneous abortions. The question used to measure TTP when the pregnant woman was interviewed at her first attended prophylactic antenatal care: 'From the time you wanted a pregnancy until it occurred, how much time passed?' could potentially have led to serious misclassification if the woman did not answer on time starting unprotected intercourse but on the start of wishing to have a child.

WIDER IMPLICATIONS OF THE FINDINGS

We found that TTP is a strong marker of survival, contributing to the still-emerging evidence that fecundity in men and women reflects their health and survival potential.

STUDY FUNDING/COMPETING INTEREST(S)

The authors acknowledge an unrestricted grant from Ferring. The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article, or the decision to submit it for publication. M.L.E. is an advisor to Ro, VSeat, Doveras, and Next.

TRIAL REGISTRATION NUMBER

N/A.

Factors influencing natural fecundity in fertile couples: a survey of puerperae and their partners

RESEARCH QUESTION

What is the fecundity rate among fertile couples, and which factors influence it?

DESIGN

Retrospective study of all puerperae attending Cruces University Hospital Human Reproduction Unit over 9 months. An anonymous questionnaire was circulated to all patients, and 2510 valid completed questionnaires were collected. The main inclusion criterion was natural conception resulting in delivery. Pregnancies resulting from ART and contraceptive method failure were excluded. Investigated parameters were time to pregnancy, age and smoking (in women and men), previous pregnancies and intercourse frequency. A mathematical formula was developed to predict the per-month fecundity rate (PMFR).

RESULTS

The cumulative fecundity rate was 29.08%, 54.26%, 68.61%, 89.88%, 96.95% and 98.63% (at 1, 3, 6, 12, 24 and 36 months); between 12 and 36 months, the average PMFR ranged from 8.53-7.48%. Only 1.68% of pregnancies occurred between 24 and 36 months, and only 1.37% thereafter. The best fecundity markers were obtained in the group who had sexual intercourse seven to eight times a week. Women and men younger than 25 years had lower fecundity markers than those aged between 25 and 40 years.

CONCLUSIONS

Fertile couples have a non-negligible per-month fecundity rate between 12 and 36 months, which should be considered when planning fertility studies. The lower fecundity rate observed in women and men aged younger than 25 years deserves more study. Coital frequencies of more than two or three times a week did not affect the fecundity rate and was better with frequencies of seven to eight times a week.

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.

The Role of Advanced Parental Age in Reproductive Genetics

The increase of parental reproductive age is a worldwide trend in modern society in recent decades. In general, older parents have a significant impact on reproductive genetics and the health of offspring. In particular, advanced parental age contributes to the increase in the risk of adverse neurodevelopmental outcomes in offspring. However, it is currently under debate how and to what extent the health of future generations was affected by the parental age. In this review, we aimed to (i) provide an overview of the effects of age on the fertility and biology of the reproductive organs of the parents, (ii) highlight the candidate biological mechanisms underlying reproductive genetic alterations, and (iii) discuss the relevance of the effect of parental age on offspring between animal experiment and clinical observation. In addition, we think that the impact of environmental factors on cognitive and emotional development of older offspring will be an interesting direction.

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.

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.

The Avon Longitudinal Study of Parents and children ALSPAC G0 Partners: A cohort profile

ALSPAC is an ongoing population-based, observational study designed to investigate how genetic/environmental characteristics might influence the health/development of children and their parents. It has evolved to facilitate the measurement of many outcomes in the parental cohort. Pregnant women resident in Bristol, UK with expected dates of delivery between April 1991-December 1992 were eligible. 14,541 pregnancies were originally enrolled. Partners of the pregnant women were initially invited to take part by the women with formal enrolment of individuals since 2010. Data has been collected from 12,113 partners, with 3,807 formally enrolled. Data collected to date: 21 questionnaires, clinical follow up in 2012 (mean age: 53 years) and a family-based clinical follow-up currently ongoing (mean age: 63 years). Questionnaires asked about a wide range of environmental measures, physical/mental health and other phenotypic details including six questionnaires throughout the COVID-19 pandemic. Clinical measures include anthropometrics, blood pressure, body composition, cardiovascular health and a fasting blood sample. DNA has been extracted with genome-wide data available on >3,000 partners and exomes on ~1500 trios. The data contributes to one of the most deeply phenotyped birth cohorts in the world, providing trios of data and multi-generational information, and is fully accessible through a managed access process.

Reproductive axis ageing and fertility in men

Compared to women, increasing male age is not accompanied by such marked changes in reproductive function but changes certainly do happen. These include alterations to the hypothalamo-pituitary-testicular axis, with resultant implications for testosterone production and bioavailability as well as spermatogenesis. There is a decline in sexual function as men age, with a dramatic increase in the prevalence of erectile dysfunction after the age of 40, which is a marker for both clinically evident as well as covert coronary artery disease. Despite a quantitative decline in spermatogenesis and reduced fecundability, the male potential for fertility persists throughout adult life, however there are also increasingly recognised alterations in sperm quality and function with significant implications for offspring health. These changes are relevant to both natural and medically assisted conception.

Testicular aging, male fertility and beyond

Normal spermatogenesis and sperm function are crucial for male fertility. The effects of healthy testicular aging and testicular premature aging on spermatogenesis, sperm function, and the spermatogenesis microenvironment cannot be ignored. Compared with younger men, the testis of older men tends to have disturbed spermatogenic processes, sperm abnormalities, sperm dysfunction, and impaired Sertoli and Leydig cells, which ultimately results in male infertility. Various exogenous and endogenous factors also contribute to pathological testicular premature aging, such as adverse environmental stressors and gene mutations. Mechanistically, Y-chromosomal microdeletions, increase in telomere length and oxidative stress, accumulation of DNA damage with decreased repair ability, alterations in epigenetic modifications, miRNA and lncRNA expression abnormalities, have been associated with impaired male fertility due to aging. In recent years, the key molecules and signaling pathways that regulate testicular aging and premature aging have been identified, thereby providing new strategies for diagnosis and treatment. This review provides a comprehensive overview of the underlying mechanisms of aging on spermatogenesis. Furthermore, potential rescue measures for reproductive aging have been discussed. Finally, the inadequacy of testicular aging research and future directions for research have been envisaged to aid in the diagnosis and treatment of testicular aging and premature aging.

Age-associated epigenetic changes in mammalian sperm: implications for offspring health and development

BACKGROUND

Modern reproductive behavior in most developed countries is characterized by delayed parenthood. Older gametes are generally less fertile, accumulating and compounding the effects of varied environmental exposures that are modified by lifestyle factors. Clinicians are primarily concerned with advanced maternal age, while the influence of paternal age on fertility, early development and offspring health remains underappreciated. There is a growing trend to use assisted reproductive technologies for couples of advanced reproductive age. Thus, the number of children born from older gametes is increasing.

OBJECTIVE AND RATIONALE

We review studies reporting age-associated epigenetic changes in mammals and humans in sperm, including DNA methylation, histone modifications and non-coding RNAs. The interplay between environment, fertility, ART and age-related epigenetic signatures is explored. We focus on the association of sperm epigenetics on epigenetic and phenotype events in embryos and offspring.

SEARCH METHODS

Peer-reviewed original and review articles over the last two decades were selected using PubMed and the Web of Science for this narrative review. Searches were performed by adopting the two groups of main terms. The first group included 'advanced paternal age', 'paternal age', 'postponed fatherhood', 'late fatherhood', 'old fatherhood' and the second group included 'sperm epigenetics', 'sperm', 'semen', 'epigenetic', 'inheritance', 'DNA methylation', 'chromatin', 'non-coding RNA', 'assisted reproduction', 'epigenetic clock'.

OUTCOMES

Age is a powerful factor in humans and rodent models associated with increased de novo mutations and a modified sperm epigenome. Age affects all known epigenetic mechanisms, including DNA methylation, histone modifications and profiles of small non-coding (snc)RNA. While DNA methylation is the most investigated, there is a controversy about the direction of age-dependent changes in differentially hypo- or hypermethylated regions with advanced age. Successful development of the human sperm epigenetic clock based on cross-sectional data and four different methods for DNA methylation analysis indicates that at least some CpG exhibit a linear relationship between methylation levels and age. Rodent studies show a significant overlap between genes regulated through age-dependent differentially methylated regions and genes targeted by age-dependent sncRNA. Both age-dependent epigenetic mechanisms target gene networks enriched for embryo developmental, neurodevelopmental, growth and metabolic pathways. Thus, age-dependent changes in the sperm epigenome cannot be described as a stochastic accumulation of random epimutations and may be linked with autism spectrum disorders. Chemical and lifestyle exposures and ART techniques may affect the epigenetic aging of sperm. Although most epigenetic modifications are erased in the early mammalian embryo, there is growing evidence that an altered offspring epigenome and phenotype is linked with advanced paternal age due to the father's sperm accumulating epigenetic changes with time. It has been hypothesized that age-induced changes in the sperm epigenome are profound, physiological and dynamic over years, yet stable over days and months, and likely irreversible.

WIDER IMPLICATIONS

This review raises a concern about delayed fatherhood and age-associated changes in the sperm epigenome that may compromise reproductive health of fathers and transfer altered epigenetic information to subsequent generations. Prospective studies using healthy males that consider confounders are recommended. We suggest a broader discussion focused on regulation of the father's age in natural and ART conceptions is needed. The professional community should be informed and should raise awareness in the population and when counseling older men.

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.

Paternal ageing impacts blastulation and the outcomes of pregnancy at different levels of maternal age: A clustering analysis of 21,960 oocytes and 3837 ICSI cycles

The objective of this cross-sectional study was to investigate the impact of paternal age on the outcomes of intracytoplasmic sperm injection (ICSI) cycles at different values of maternal age. A total of 21,960 injected oocytes deriving from 3837 ICSI cycles performed between January 2014 and October 2020, performed in a private university-affiliated in vitro fertilization centre was included. The main effects of maternal and paternal age, as well as the effect of their product (interaction term) on embryo development and pregnancy outcomes were investigated considering the clustering of data. The coefficients for the interaction term were statistically significant for blastocyst development, top-quality blastocyst, implantation, pregnancy, miscarriage, and live-birth rates. For every 1-year increase in paternal age, the odds ratio of live-birth reduces by 1% in females aged 37 years, 1.6% in those aged 38 years, 2.4% in 39-year-old females, 5% in 42-year-old females and so on. An increase in the interaction term by 1 year decreases the pregnancy rate by 0.4% and live-birth rate by 0.8 and increases the miscarriage rate by 1.2%. The slopes of maternal age on blastulation, blastocyst quality, and implantation, pregnancy, miscarriage, and live-birth rate significantly changed (worsened) for every year increase in paternal age.

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.

Secondary infertility with a history of vaginal childbirth: Ready to have another one?

INTRODUCTION

Up to 30% of couples may face secondary infertility. The impact of ectopic pregnancy, spontaneous abortion, pregnancy termination or live birth with caesarean section may impair further fertility in different ways. However, secondary infertility after physiological vaginal life childbirth has been little studied. The aim of this study was to describe the population and the fertility issues and analyze the predictive factors of success in in vitro fertilization in women presenting secondary infertility after a physiological vaginal childbirth.

MATERIAL AND METHODS

This single-centre retrospective study included women aged 18-43 years consulting between 2013 and 2020 for secondary infertility in a couple having already had previous vaginal life childbirth. Couples' characteristics, management decision after the first consultation and IVF outcomes were analyzed.

RESULTS

Secondary infertility was found in 286 couples, out of whom 138 had a history of vaginal life childbirth. Population was characterized by an advanced female age and overweight. After the first consultation, IVF was performed in only 40% of couples. No predictive factor of live birth was found.

CONCLUSION

Our study shows that in couples with secondary infertility after prior physiological delivery cigarette smoking is frequent in male partners, and ovarian reserve markers are altered. However, no statistically significant predictive factor of live birth after IVF treatment has been identified. Further large prospective studies are necessary.

Spousal associations of serum metabolomic profiles by nuclear magnetic resonance spectroscopy

Phenotype-based assortative mating is well established in humans, with the potential for further convergence through a shared environment. To assess the correlation within infertile couples of physical, social, and behavioural characteristics and 155 circulating metabolic measures. Cross sectional study at a tertiary medical center of 326 couples undertaking IVF. Serum lipids, lipoprotein subclasses, and low-molecular weight metabolites as quantified by NMR spectroscopy (155 metabolic measures). Multivariable and quantile regression correlations within couples of metabolite profiles. Couples exhibited statistical correlations of varying strength for most physical, social, and behavioural characteristics including age, height, alcohol consumption, education, smoking status, physical activity, family history and ethnicity, with correlation coefficients ranging from 0.22 to 0.73. There was no evidence of within couple associations for BMI and weight, where the correlation coefficients were - 0.03 (95% CI - 0.14, 0.08) and 0.01 (95% CI - 0.10, 0.12), respectively. Within spousal associations of the metabolite measurements were all positive but with weak to modest magnitudes, with the median correlation coefficient across all 155 measures being 0.12 (range 0.01-0.37 and interquartile range 0.10-0.18). With just four having associations stronger than 0.3: docosahexaenoic acid (0.37, 95% CI 0.22, 0.52), omega-3 fatty acids (0.32, 95% CI 0.20, 0.43) histidine (0.32, 95% CI 0.23, 0.41) and pyruvate (0.32, 95% CI 0.22, 0.43). Infertile couples exhibit spousal similarities for a range of demographic and serum metabolite measures, supporting initial assortative mating, with diet-derived metabolites suggesting possible subsequent convergence of their individual metabolic profile.

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.

Parental age and preterm birth: a population-based cohort of nearly 3 million California livebirths from 2007 to 2012

PURPOSE

To assess the relationships between parental ages and preterm birth subtypes.

METHODS

A population-based cohort analysis of California livebirths 2007-2012. Associations between maternal and paternal age with spontaneous and medically indicated preterm birth were estimated from Cox proportional hazard models. Parental age was modeled with restricted cubic splines to account for nonlinear relationships.

RESULTS

Young paternal age was associated with increased hazard ratios for spontaneous and medically indicated preterm birth. Older fathers showed elevated hazards for preterm birth in crude analysis but after adjustment the relationship was generally not observed. Aging mothers showed increased hazard ratios for both preterm birth phenotypes.

CONCLUSIONS

After adjusting for parental demographics, births to younger fathers and older mothers had the highest risks for spontaneous preterm birth. The paternal influence on preterm birth was observed to be independent of maternal factors.

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.

Investigation of genotype-phenotype correlation in patients with AZF microdeletion in a single-reference centre

In this study, we aimed to elucidate the relationship between AZF deletion type and clinical information of azoospermic patients with AZF microdeletion in the Turkish population. Azoospermic patients with normal karyotype and AZF microdeletion were analysed retrospectively by collecting clinical data including hormone profile, demographic characteristics and micro-TESE results. As a result of the AZF microdeletion tests of 42 cases with 46 XY karyotype, AZFa deletion was detected in 3 cases, AZFb deletion in 2 cases, AZFc deletion in 31 cases, AZFb + AZFc deletion in 4 cases and AZFa + AZFb + AZFc deletion in 2 cases respectively. Spermatozoon was obtained in 16 cases with AZFc microdeletion with micro-TESE. Pregnancy was achieved in 2 cases. There was no statistically significant difference between the type of deletion and age, height, weight, body mass index, hormone profile and testicular volume. When AZF is evaluated according to the type of microdeletion, it will be appropriate to plan the medical and surgical options more carefully in a multidisciplinary manner in cases with deletions including AZFa, AZFb or their combinations. Also, genotype-phenotype correlation was found to be consistent with the literature; particularly patients having AZFc deletions were found to have a chance for pregnancy.

Improving Sperm Oxidative Stress and Embryo Quality in Advanced Paternal Age Using Idebenone In Vitro-A Proof-of-Concept Study

Advanced paternal age is associated with increased sperm reactive oxygen species (ROS) and decreased fertilization and pregnancy rates. Sperm washing during infertility treatment provides an opportunity to reduce high sperm ROS concentrations associated with advanced paternal age through the addition of idebenone. Sperm from men aged >40 years and older CBAF1 mice (12–18 months), were treated with 5 µM and 50 µM of idebenone and intracellular and superoxide ROS concentrations assessed. Following in vitro fertilization (IVF), embryo development, blastocyst differentiation, DNA damage and cryosurvival, pregnancy and implantation rates and fetal and placental weights were assessed. Five µM of idebenone given to aged human and mouse sperm reduced superoxide concentrations ~20% (p < 0.05), while both 5 and 50 µM reduced sperm intracellular ROS concentrations in mice ~30% (p < 0.05). Following IVF, 5 µM of idebenone to aged sperm increased fertilization rates (65% vs. 60%, p < 0.05), blastocyst total, trophectoderm and inner cell mass cell numbers (73 vs. 66, 53 vs. 47 and 27 vs. 24, respectively, p < 0.01). Treatment with idebenone also increased blastocyst cryosurvival rates (96% vs. 78%, p < 0.01) and implantation rates following embryo transfer (35% vs. 18%, p < 0.01). Placental weights were smaller (107 mg vs. 138 mg, p < 0.05), resulting in a larger fetal to placental weight ratio (8.3 vs. 6.3, p = 0.07) after sperm idebenone treatment. Increased sperm ROS concentrations associated with advanced paternal age are reduced with the addition of idebenone in vitro, and are associated with improved fertilization rates, embryo quality and implantation rates after IVF.

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.

Proteostasis in the Male and Female Germline: A New Outlook on the Maintenance of Reproductive Health

For fully differentiated, long lived cells the maintenance of protein homeostasis (proteostasis) becomes a crucial determinant of cellular function and viability. Neurons are the most well-known example of this phenomenon where the majority of these cells must survive the entire course of life. However, male and female germ cells are also uniquely dependent on the maintenance of proteostasis to achieve successful fertilization. Oocytes, also long-lived cells, are subjected to prolonged periods of arrest and are largely reliant on the translation of stored mRNAs, accumulated during the growth period, to support meiotic maturation and subsequent embryogenesis. Conversely, sperm cells, while relatively ephemeral, are completely reliant on proteostasis due to the absence of both transcription and translation. Despite these remarkable, cell-specific features there has been little focus on understanding protein homeostasis in reproductive cells and how/whether proteostasis is "reset" during embryogenesis. Here, we seek to capture the momentum of this growing field by highlighting novel findings regarding germline proteostasis and how this knowledge can be used to promote reproductive health. In this review we capture proteostasis in the context of both somatic cell and germline aging and discuss the influence of oxidative stress on protein function. In particular, we highlight the contributions of proteostasis changes to oocyte aging and encourage a focus in this area that may complement the extensive analyses of DNA damage and aneuploidy that have long occupied the oocyte aging field. Moreover, we discuss the influence of common non-enzymatic protein modifications on the stability of proteins in the male germline, how these changes affect sperm function, and how they may be prevented to preserve fertility. Through this review we aim to bring to light a new trajectory for our field and highlight the potential to harness the germ cell's natural proteostasis mechanisms to improve reproductive health. This manuscript will be of interest to those in the fields of proteostasis, aging, male and female gamete reproductive biology, embryogenesis, and life course health.

Protective effects of ginseng stem-leaf saponins on D-galactose-induced reproductive injury in male mice

Panax ginseng is a perennial plant in the Araliaceae family. In this study, we investigated the protective effects of ginseng stem-leaf saponins (GSLS) isolated from P. ginseng against D-galactose-induced reproductive function decline, oxidative stress, and inflammatory response. Reproductive injuries were induced in mice via the subcutaneous injection of D-galactose (300 mg/kg) for six weeks. The mice were then treated with GSLS by intragastric administration. GSLS inhibited markers of oxidative stress and inflammatory cytokines induced by D-galactose in serum, liver and kidney, whereas GSLS increased the activities of antioxidant enzymes. Compared to the mice treated only with D-galactose, GSLS treatment significantly increased the average path velocity, straight line velocity, curvilinear velocity, and amplitude of the lateral head displacement of mouse sperm. Meanwhile, GSLS significantly increased the testosterone level and reduced the cortisol, FSH, and LH levels. Histopathological examination revealed alterations in the number and the arrangement of spermatogenic cells in the seminiferous tubules of the mice in the GSLS group. GSLS treatment suppressed MAPKs pathway activation in testes. These results suggest that GSLS can attenuate D-galactose-induced oxidative stress and inflammatory response in serum, liver and kidney, and ameliorate reproductive damage by inhibiting MAPKs signaling pathway.

Aging increases oxidative stress in semen

Purpose

As age increases, oxidative stress increases, sperm motility decreases, and DNA fragmentation increases. To date, reports of age-related effects on semen have focused on reactive oxygen species (ROS) or total antioxidant capacity (TAC) as indicators of oxidative stress. However, assessments of ROS and TAC must be considered within a more comprehensive context in order to correctly evaluate oxidative stress and interpret findings. In this regard, the purpose of this study was to investigate the relationship between the static oxidation reduction potential (sORP) and paternal age with the goal of using the sORP as an indicator of semen oxidative stress.

Materials and Methods

Semen samples from 173 men were analyzed for the following parameters: volume, motility, and beat cross frequency (BCF). The sORP was measured by using the MiOXSYS™ system. The correlation between semen parameters and the sORP level was analyzed as a function of age. The rate of sORP positivity was compared between men <34 and ≥34 years of age, with a positive sORP defined as a level ≥1.38.

Results

Volume, motility, and BCF were negatively correlated with age (p<0.001). The semen sORP level was positively correlated with age (p<0.05). The rate of sORP positivity was significantly increased in men ≥34 years of age compared with that in men <34 years of age (33% compared with 12%, respectively; p<0.01).

Conclusions

The sORP may play a role in age-related decreases in semen parameters (volume, motility, and BCF). The rate of sORP positivity increased significantly after 34 years of age.

Predictive factors for intrauterine insemination outcomes: a review

PURPOSE

Intrauterine insemination (IUI) is a frequently utilized method of assisted reproduction for patients with mild male factor infertility, anovulation, endometriosis, and unexplained infertility. The purpose of this review is to discuss factors that affect IUI outcomes, including infertility diagnosis, semen parameters, and stimulation regimens.

METHODS

We reviewed the published literature to evaluate how patient and cycle specific factors affect IUI outcomes, specifically clinical pregnancy rate, live birth rate, spontaneous abortion rate and multiple pregnancy rate.

RESULTS

Most data support IUI for men with a total motile count > 5 million and post-wash sperm count > 1 million. High sperm DNA fragmentation does not consistently affect pregnancy rates in IUI cycles. Advancing maternal and paternal age negatively impact pregnancy rates. Paternal obesity contributes to infertility while elevated maternal BMI increases medication requirements without impacting pregnancy outcomes. For ovulation induction, letrozole and clomiphene citrate result in similar pregnancy outcomes and are recommended over gonadotropins given increased risk for multiple pregnancies with gonadotropins. Letrozole is preferred for obese women with polycystic ovary syndrome. IUI is most effective for women with ovulatory dysfunction and unexplained infertility, and least effective for women with tubal factor and stage III-IV endometriosis. Outcomes are similar when IUI is performed with ovulation trigger or spontaneous ovulatory surge, and ovulation may be monitored by urine or serum. Most pregnancies occur within the first four IUI cycles, after which in vitro fertilization should be considered.

CONCLUSIONS

Providers recommending IUI for treatment of infertility should take into account all of these factors when evaluating patients and making treatment recommendations.

Paternal programming of offspring health

In recent years, a new focus of the Developmental Origins of Health and Disease hypothesis has emerged examining the potential role that paternal health may play in embryo development, fetal growth and long-term offspring health. While the association between male health and sperm quality has been studied in detail, our understanding of the long-term paternal effects on offspring health remains limited. As with studies aimed at understanding maternal programming, animal models are an essential tool with which to define the underlying mechanisms linking paternal health to post-fertilisation development and offspring well-being. Here, new insights into the genetic and epigenetic nature of the sperm, as well as the role seminal plasma plays in modulating the maternal reproductive environment, are demonstrating the significant role a father's wellbeing at the time of conception has for programming the health of his offspring. In this article we will outline the current understanding of the impact of male health on semen quality, reproductive fitness and post-fertilisation offspring development and explore the mechanisms underlying the paternal programming of offspring health.

Australian Veterans of the Middle East Conflicts 2001–2010: Select Reproductive Health Outcomes Part 1 — Maternal and Paternal Outcomes

Background: Anecdotally, infertility concerns among serving female Australian Defense Force (ADF) members and veterans are perceived to be prevalent, but precise data are lacking. This is the first of two papers that identify reproductive, pregnancy, and infant outcomes in an exclusively Australian military cohort. This initial paper aims to describe maternal and paternal occupation and fertility characteristics of a group of ADF members who deployed to the Middle East during the period 2001–2010.

Methods: Utilizing the Middle East Area of Operations Census Study data set, a descriptive analysis was performed on the demographic and clinical variables of the cohort, where data were reported. Descriptive statistics (means, frequencies, percentiles) were used to describe the population. Sociodemographic data and clinical data, including maternal/paternal outcomes, were reported.

Results: The self-reported infertility rate was 9%, which was significantly lower than the reported infertility rate in the comparative Australian (non-military) population. All other outcomes were comparable to the Australian population and within normal limits.

Conclusions: This survey presents a generally reassuring picture of reproductive health for men and women serving in the ADF with regard to the risk of infertility, pregnancy loss, and perinatal outcomes, although the basis for fertility concerns requires further investigation.

Intrinsic post-ejaculation sperm ageing does not affect offspring fitness in Atlantic salmon

Post-meiotic sperm ageing, both before ejaculation and after ejaculation, has been shown to negatively affect offspring fitness by lowering the rate of embryonic development, reducing embryonic viability and decreasing offspring condition. These negative effects are thought to be caused by intrinsic factors such as oxidative stress and ATP depletion or extrinsic factors such as temperature and osmosis. Effects of post-ejaculation sperm ageing on offspring fitness have so far almost exclusively been tested in internal fertilizers. Here, we tested whether intrinsic post-ejaculation sperm ageing affects offspring performance in an external fertilizer, the Atlantic salmon Salmo salar. We performed in vitro fertilizations with a split-clutch design where sperm were subjected to four post-ejaculation ageing treatments. We varied the duration between sperm activation and fertilization while minimizing extrinsic stress factors and tested how this affected offspring fitness. We found no evidence for an effect of our treatments on embryo survival, hatching time, larval standard length, early larval survival or larval growth rate, indicating that intrinsic post-ejaculation sperm ageing may not occur in Atlantic salmon. One reason may be the short life span of salmon sperm after ejaculation. Whether our findings are true in other external fertilizers with extended sperm activity remains to be tested.

Reasons that should prompt a referral to a reproductive urologist: guidelines for the gynecologist and reproductive endocrinologist

Obstetricians and gynecologists, and in particular reproductive endocrinologists (REIs), are typically the gatekeepers and first-line providers for couples initially seeking an infertility evaluation. A timely referral to a reproductive urologist may improve pregnancy outcomes in certain clinical scenarios. This review examines the evidence behind circumstances requiring referral and delivers practice-based recommendations on commonly encountered scenarios in the clinic. Scenarios that should prompt referral to a reproductive urologist include semen analysis (SA) abnormalities (e.g., asthenozoospermia, azoospermia, globozoospermia, leukocytospermia, necrozoospermia, oligospermia), recurrent intrauterine insemination (IUI)/in vitro fertilization (IVF) failure, and idiopathic recurrent pregnancy loss (RPL). Conversely, deferment is appropriate in the cases of isolated teratozoospermia and subclinical varicocele. Men with infertility are also at higher risk for other comorbid conditions and should have at least a baseline evaluation by a primary care physician. Coordination of care between a REI and reproductive urologist is critical in several clinical scenarios and expedient referral can improve reproductive outcomes.

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.

Aging and the Male Reproductive System

This narrative review presents an overview of current knowledge on fertility and reproductive hormone changes in aging men, the factors driving and modulating these changes, their clinical consequences, and the benefits and risks of testosterone (T) therapy. Aging is accompanied by moderate decline of gamete quality and fertility. Population mean levels show a mild total T decline, an SHBG increase, a steeper free T decline, and a moderate LH increase with important contribution of comorbidities (e.g., obesity) to these changes. Sexual symptoms and lower hematocrit are associated with low T and are partly responsive to T therapy. The relationship of serum T with body composition and metabolic health is bidirectional; limited beneficial effects of T therapy on body composition have only marginal effects on metabolic health and physical function. Skeletal changes are associated primarily with estradiol and SHBG. Cognitive decline is not consistently linked to low T and is not improved by T therapy. Although limited evidence links moderate androgen decline with depressive symptoms, T therapy has small beneficial effects on mood, depressive symptoms, and vitality in elderly patients with low T. Suboptimal T (and/or DHT) has been associated with increased risk of stroke, but not of ischemic heart disease, whereas an association with mortality probably reflects that low T is a marker of poor health. Globally, neither severity of clinical consequences attributable to low T nor the nature and magnitude of beneficial treatment effects justify the concept of some broadly applied "T replacement therapy" in older men with low T. Moreover, long-term safety of T therapy is not established.

Effect of paternal age on intracytoplasmic sperm injection outcomes in cryptozoospermic men: Ejaculated or testicular sperm?

It is not clear whether age has any influence on the outcomes for sperm used for assisted reproductive technology in cryptozoospermic men. We evaluated intracytoplasmic sperm injection (ICSI) outcomes using ejaculated or testicular sperm in men with cryptozoospermia from different paternal age ranges.We conducted a retrospective observational study of 35 men with cryptozoospermia who underwent ICSI from 2010 to 2018. They were classified into 2 groups based on male age, namely < 35 years and ≥ 35 years. Each group was further divided into 2 subgroups according to the origin of sperm (ejaculated or testicular).In the <35 years group, the normal fertilization and high-quality embryo rates for ejaculated sperm were significantly higher than with testicular sperm (74.7% vs. 62.4%, P = .02; 50.5% vs. 36.6%, P = .03, respectively). However, in the ≥35 years group, the high-quality embryo and clinical pregnancy rates were significantly lower in the ejaculated sperm subgroup than in the testicular sperm subgroup (26.2% vs. 63%, P = .002; 12.5% vs. 71.4%, P = .04, respectively).This study indicates that ICSI should be performed as soon as possible for men with cryptozoospermia. When the paternal age ≥35 years, testicular sperm should be used for ICSI, as this offers better high-quality embryo and clinical pregnancy rates.

Mid-life fertility: Challenges & policy planning

This review highlights the challenges, priority areas of research and planning, strategies for regulation of services and the need to develop guidelines and laws for fertility treatments during mid-life. The success rate of all treatments is poor in advanced age women because of declining ovarian reserve and natural fertility. There is often a need of third-party involvement which has its own ethical, legal and medical issues. Welfare of children born to older women and early death of parents are important concerns. Most of the new techniques such as the pre-implantation genetic diagnosis, oocyte augmentation, use of stem cells or artificial gametes, ovarian tissue preservation and ovarian transplantation are directed to improve, preserve or replace the declining ovarian reserve. These techniques are costly and have limited availability, safety and efficacy data. Continued research and policies are required to keep pace with these techniques. The other important issues include the patients’ personal autonomy and right of self-determination, welfare of offspring, public vs. private funding for research and development of new technologies vs. indiscriminate use of unproven technology. It is important that mid-life fertility is recognized as a distinct area of human reproduction requiring special considerations.

Impact of advanced paternal age on the intracytoplasmic sperm injection (ICSI) outcomes in donor egg cycles

Background

The purpose of this study is to assess the impact of paternal age on the oocyte-donation outcomes in intracytoplasmic sperm injection (ICSI) cycles.

Methods

Two hundred and seventy-eight infertile couples were retrospectively involved. Inclusion criteria were: infertility from almost 1 year, normal or sub-fertile seminal parameters, overall oocyte survival rate greater than 85%. Baseline characteristics included male age, recipient age, male body mass index (BMI), smoking, drinking status. Main outcome measures: fertilization rate (FR), cleavage rate (CR), pregnancy rate (PR).

Results

Patients were categorized in group 1 ≤45, group 2 >45 years. A total of 1,724 frozen oocytes were included. After warming, 1,642 oocytes survived. Median overall oocyte survival rate was 100% [interquartile range (IQR), 85-100%]. Median male age was 44±5.60 years (IQR, 31-70 years). Median recipients age was 42±3.62 years (IQR, 29-50 years). Group 1 included 166 men, group 2 112 men. Two hundred and seventy-eight fresh ICSI cycle were performed. "Two-pronuclear" (2PN) FR was 72.6%±0.20%, CR 93.0%±0.16%, PR 39.6%. Miscarriage rate was 25.5%. Live birth rate per cycles was 29.5%. Comparison between group 1, group 2 and ICSI outcomes confirmed an association with FR, resulting 80.0% (IQR, 67.0-83.0%) and 67.0% (IQR, 50.0-80.0%), respectively (P<0.01). There were no significant differences between the two groups with respect to seminal parameters.

Conclusions

It would be recommended more emphasis on the advancing male age when counselling older couples who undergo egg donation program.

Paternal germ line aging: DNA methylation age prediction from human sperm

Background

The relationship between aging and epigenetic profiles has been highlighted in many recent studies. Models using somatic cell methylomes to predict age have been successfully constructed. However, gamete aging is quite distinct and as such age prediction using sperm methylomes is ineffective with current techniques.

Results

We have produced a model that utilizes human sperm DNA methylation signatures to predict chronological age by utilizing methylation array data from a total of 329 samples. The dataset used for model construction includes infertile patients, sperm donors, and individuals from the general population. Our model is capable predicting age with an R2 of 0.89, a mean absolute error (MAE) of 2.04 years, and a mean absolute percent error (MAPE) of 6.28% in our data set. We additionally investigated the reproducibility of prediction with our model in an independent cohort where 6 technical replicates of 10 individual samples were tested on different arrays. We found very similar age prediction accuracy (MAE = 2.37 years; MAPE = 7.05%) with a high degree of precision between replicates (standard deviation of only 0.877 years). Additionally, we found that smokers trended toward increased age profiles when compared to ‘never smokers’ though this pattern was only striking in a portion of the samples screened.

Conclusions

The predictive model described herein was built to offer researchers the ability to assess “germ line age” by accessing sperm DNA methylation signatures at genomic regions affected by age. Our data suggest that this model can predict an individual’s chronological age with a high degree of accuracy regardless of fertility status and with a high degree of repeatability. Additionally, our data suggest that the aging process in sperm may be impacted by environmental factors, though this effect appears to be quite subtle and future work is needed to establish this relationship.

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.

GONADOPENIA AND AGING IN MEN

OBJECTIVE

The decrease in testosterone levels that occurs with aging has become an important clinical issue both due to the growth of the geriatric population and patient interest in testosterone therapy. The decision to assess for testosterone deficiency and the ability to determine whether the benefits exceed the risks require a comprehensive evaluation of the aging patient. This article is part of a series of papers focused on the endocrinology of aging. This review addresses common issues needed for clinical decision making, including how to interpret test results, differential diagnosis, potential impact of testosterone treatment on insulin resistance and cardiovascular disease, and options for therapy.

METHODS

Papers reviewed were identified through literature searches conducted on PubMed.

RESULTS

Assessment of testosterone levels in the geriatric male requires an understanding of the limitations of the assay that is used, the symptoms associated with low testosterone, the impact of comorbid conditions on levels, and risks of therapy. Successful treatment requires setting realistic expectations of the benefits of replacement therapy.

CONCLUSION

While the prevalence of low testosterone concentrations is increased with aging, the common comorbidities such as obesity and diabetes may contribute to changes in testosterone levels. Clinical trial evidence shows modest benefit for treatment of low testosterone in the presence of symptoms. Assessment of the geriatric male should include evaluation of their testosterone level in the context of their functional status and comorbidities.

ABBREVIATIONS

CDC = Centers for Disease Control and Prevention; CI = confidence interval; CVD = cardiovascular disease; DXA = dual-energy X-ray absorptiometry; EMAS = European Male Aging Study; FDA = U.S. Food and Drug Administration; FHS = Framingham Heart Study; HDL = high-density lipoprotein; HOMA-IR = homeostasis model assessment of insulin resistance; LH = luteinizing hormone; OR = odds ratio; PSA = prostate-specific antigen; SHBG = sex hormone-binding globulin; T2DM = type 2 diabetes mellitus; vBMD = volumetric bone mineral density.

Conceptualising women's motivations for social egg freezing and experience of reproductive delay

As the average age of motherhood in many Western countries continues to rise, the spectacle of the older mother and the trend towards delayed childbearing has been the subject of much public debate and interest. Concurrent to this trend has been the development and use of a new form of fertility preservation - social egg freezing - a technology which by its very nature is meant to enable reproductive delay. Whilst previous studies have been able to provide insights into the complex and often interrelating structural, economic, and relational factors shaping the timing of motherhood, and in some cases women's use of social egg freezing, fewer studies have clearly demonstrated the way these factors themselves, as well as the accounts of individual women, can be seen as being shaped by ideological and discursive forces. Drawing on interviews with 31 users of social egg freezing this article will demonstrate how women's accounts of reproductive delay and use of egg freezing technology can be seen as being shaped by neoliberal rationality, heteronormativity, discourses of 'appropriate parenting' and gendered ideologies of parenthood.

Reproductive genetics and the aging male

PURPOSE

To examine current evidence of the known effects of advanced paternal age on sperm genetic and epigenetic changes and associated birth defects and diseases in offspring.

METHODS

Review of published PubMed literature.

RESULTS

Advanced paternal age (> 40 years) is associated with accumulated damage to sperm DNA and mitotic and meiotic quality control mechanisms (mismatch repair) during spermatogenesis. This in turn causes well-delineated abnormalities in sperm chromosomes, both numerical and structural, and increased sperm DNA fragmentation (3%/year of age) and single gene mutations (relative risk, RR 10). An increase in related abnormalities in offspring has also been described, including miscarriage (RR 2) and fetal loss (RR 2). There is also a significant increase in rare, single gene disorders (RR 1.3 to 12) and congenital anomalies (RR 1.2) in offspring. Current research also suggests that autism, schizophrenia, and other forms of "psychiatric morbidity" are more likely in offspring (RR 1.5 to 5.7) with advanced paternal age. Genetic defects related to faulty sperm quality control leading to single gene mutations and epigenetic alterations in several genetic pathways have been implicated as root causes.

CONCLUSIONS

Advanced paternal age is associated with increased genetic and epigenetic risk to offspring. However, the precise age at which risk develops and the magnitude of the risk are poorly understood or may have gradual effects. Currently, there are no clinical screenings or diagnostic panels that target disorders associated with advanced paternal age. Concerned couples and care providers should pursue or recommend genetic counseling and prenatal testing regarding specific disorders.

Infertility in the Aging Male

PURPOSE OF REVIEW

In many countries, the average age of paternity is rising. The negative effect of older age on fertility in women is well documented; however, less is known about the impact of paternal age on fecundity. In this review, we summarize the current knowledge of how paternal age affects semen parameters, reproductive success, and offspring health.

RECENT FINDINGS

Contemporary evidence confirms that aged men have worse semen parameters, including overall negative changes in sperm genetics. Reproductive outcomes with unassisted pregnancy tend to be worse with older fathers. While most current studies of assisted pregnancy do show a negative effect of paternal age, there are some conflicting results. Studies continue to show an overall increased risk of health problems, particularly neuropsychiatric conditions, in the offspring of older men. While men can often maintain fertility potential throughout a lifetime, increasing evidence indicates worsening of semen parameters, including sperm genetics, and potentially worse reproductive success. Older men should also be counseled on their offspring's possible increased risk of certain medical conditions.

Age difference between parents influences parity and number of sons

OBJECTIVES

Among couples, women usually prefer slightly older men, and men tend to choose much younger partners. Age difference between partners has been shown to influence their parity; however, results of previous studies are inconsistent. This study analyzed relationships between husband and wife age difference and their total number of children, and number of daughters and sons in a contemporary, rural Polish population.

METHODS

Demographic and reproductive data were collected from 384 postmenopausal women from rural Poland who were married only once. Regression models were used to evaluate the impact of the age gap between partners on total number of children and on number of daughters and sons. Women's age, age at marriage (as an indicator of reproductive value), and years of education were used in analyzes as potential confounders.

RESULTS

There was an inverted U-shape association between parental age difference and number of children and also the number of sons. The highest number of children and sons was observed when men were approximately 6.5 years older than their wives. There was no significant relationship between parental age difference and number of daughters.

CONCLUSIONS

Age difference between partners is important for reproductive success (with younger wives having higher reproductive potential) and is also related to number of sons. Older husbands might provide more resources for the family, thus facilitating production of well-nourished male offspring. Future research should evaluate not only number of children but also their biological condition, health, and lifetime achievements in relation to the age difference between their parents.