Mechanisms of Germline Stem Cell Competition across Species

In this review, we introduce the concept of cell competition, which occurs between heterogeneous neighboring cell populations. Cells with higher relative fitness become "winners" that outcompete cells of lower relative fitness ("losers"). We discuss the idea of super-competitors, mutant cells that expand at the expense of wild-type cells. Work on adult stem cells (ASCs) has revealed principles of neutral competition, wherein ASCs can be stochastically lost and replaced, and of biased competition, in which a winning ASC with a competitive advantage replaces its neighbors. Germline stem cells (GSCs) are ASCs that are uniquely endowed with the ability to produce gametes and, therefore, impact the next generation. Mechanisms of GSC competition have been elucidated by studies in Drosophila gonads, tunicates, and the mammalian testis. Competition between ASCs is thought to underlie various forms of cancer, including spermatocytic tumors in the human testis. Paternal age effect (PAE) disorders are caused by de novo mutations in human GSCs that increase their competitive ability and make them more likely to be inherited, leading to skeletal and craniofacial abnormalities in offspring. Given its widespread effects on human health, it is important to study GSC competition to elucidate how cells can become winners or losers.

SMAD4 mutations causing Myhre syndrome are under positive selection in the male germline

While it is widely thought that de novo mutations (DNMs) occur randomly, we previously showed that some DNMs are enriched because they are positively selected in the testes of aging men. These "selfish" mutations cause disorders with a shared presentation of features, including exclusive paternal origin, significant increase of the father's age, and high apparent germline mutation rate. To date, all known selfish mutations cluster within the components of the RTK-RAS-MAPK signaling pathway, a critical modulator of testicular homeostasis. Here, we demonstrate the selfish nature of the SMAD4 DNMs causing Myhre syndrome (MYHRS). By analyzing 16 informative trios, we show that MYHRS-causing DNMs originated on the paternally derived allele in all cases. We document a statistically significant epidemiological paternal age effect of 6.3 years excess for fathers of MYHRS probands. We developed an ultra-sensitive assay to quantify spontaneous MYHRS-causing SMAD4 variants in sperm and show that pathogenic variants at codon 500 are found at elevated level in sperm of most men and exhibit a strong positive correlation with donor's age, indicative of a high apparent germline mutation rate. Finally, we performed in vitro assays to validate the peculiar functional behavior of the clonally selected DNMs and explored the basis of the pathophysiology of the different SMAD4 sperm-enriched variants. Taken together, these data provide compelling evidence that SMAD4, a gene operating outside the canonical RAS-MAPK signaling pathway, is associated with selfish spermatogonial selection and raises the possibility that other genes/pathways are under positive selection in the aging human testis.

Clinical-grade whole genome sequencing-based haplarithmisis enables all forms of preimplantation genetic testing

High-throughput sequencing technologies have increasingly led to discovery of disease-causing genetic variants, primarily in postnatal multi-cell DNA samples. However, applying these technologies to preimplantation genetic testing (PGT) in nuclear or mitochondrial DNA from single or few-cells biopsied from in vitro fertilised (IVF) embryos is challenging. PGT aims to select IVF embryos without genetic abnormalities. Although genotyping-by-sequencing (GBS)-based haplotyping methods enabled PGT for monogenic disorders (PGT-M), structural rearrangements (PGT-SR), and aneuploidies (PGT-A), they are labour intensive, only partially cover the genome and are troublesome for difficult loci and consanguineous couples. Here, we devise a simple, scalable and universal whole genome sequencing haplarithmisis-based approach enabling all forms of PGT in a single assay. In a comparison to state-of-the-art GBS-based PGT for nuclear DNA, shallow sequencing-based PGT, and PCR-based PGT for mitochondrial DNA, our approach alleviates technical limitations by decreasing whole genome amplification artifacts by 68.4%, increasing breadth of coverage by at least 4-fold, and reducing wet-lab turn-around-time by ~2.5-fold. Importantly, this method enables trio-based PGT-A for aneuploidy origin, an approach we coin PGT-AO, detects translocation breakpoints, and nuclear and mitochondrial single nucleotide variants and indels in base-resolution.

Diverse pathways to permanent childlessness in Singapore: A latent class analysis

The proportions of adults reaching midlife without having children have been rising rapidly across the globe, particularly in Asia. However, little is known about the pathways to permanent childlessness within the region's childless population. This study utilized latent class analysis (LCA) to typologize pathways to childlessness based on dynamic characteristics of multiple life domains (i.e., partnership, education, and occupation) among 489 childless Singaporeans aged 50 and above from a 2022 nationwide survey. Additionally, we utilized multinomial logistic regressions to examine the sociodemographic correlates of pathway profiles and Shannon's entropy index to assess the heterogeneity in pathways to childlessness among successive cohorts. Results revealed five distinct profiles of pathways to childlessness: the Never-Married Semi-Professionals, the Low-Flex Blue-Collars, the Highly Educated Professionals, the Ever-Married Semi-Professionals, and the Flexible Blue-Collars. These pathway profiles were significantly associated with sociodemographic characteristics such as gender and family background. Women's pathways to childlessness were more standardized and heavily influenced by partnership characteristics, compared to those of men. The childless from privileged family background were less likely to follow pathways characterized by disadvantageous education and occupational status. There were also rising trends of voluntary childlessness among married childless individuals and increasing heterogeneity in pathways to childlessness across successive birth cohorts. In sum, our findings are consistent with some of the predictions of the Second Demographic Transition theory, suggesting that Singapore may be experiencing a demographic transition characterized by rising childlessness, decoupling of marriage and childbearing, and de-standardization of the life course.

Myhre syndrome in adulthood: clinical variability and emerging genotype-phenotype correlations

Myhre syndrome (MS, MIM 139210) is a rare multisystemic disorder caused by recurrent pathogenic missense variants in SMAD4. The clinical features have been mainly documented in childhood and comprise variable neurocognitive development, recognizable craniofacial features, a short stature with a pseudo-muscular build, hearing loss, thickened skin, joint limitations, diverse cardiovascular and airway manifestations, and increased fibrosis often following trauma or surgery. In contrast, adults with MS are underreported obscuring potential clinical variability. Here, we describe 24 adults with MS, including 17 diagnosed after the age of 18 years old, and we review the literature on adults with MS. Overall, our cohort shows a milder phenotype as well as lower mortality rates compared to what has been published in literature. Individuals with a codon 500 variant in SMAD4 present with a more pronounced neurodevelopmental and systemic phenotype. However, in contrast to the literature, we observe cardiovascular abnormalities in individuals with the p.(Arg496Cys) variant. In addition, we describe scoliosis as a new manifestation and we report fertility in two additional males with the p.(Arg496Cys). In conclusion, our study contributes novel insights into the clinical variability of MS and underscores the importance of variant-specific considerations, and we provide recommendations for the management of MS in adulthood.

Estimation of couple fecundity in the general population and the association with monthly time-varying ambient particulate matter exposure in low- and middle-income countries: A population-based multi-center epidemiological study

BACKGROUND

Declining total fertility rates have been observed in low- and middle-income countries (LMICs). However, it remains unclear if this trend is related to a reduction in fecundity of general population. Research evidence on contributing factors to fecundity reduction is also limited. We aimed to first estimate couple fecundity in LMICs and then investigate its association with ambient particulate matter (PM) exposure.

METHODS

Using the information from Demographic and Health Surveys between 2003 and 2019, we estimated median time to pregnancy (TTP) and infertility prevalence across 30 LMICs, by employing a current duration approach. Individual PM (PM1, PM2.5, and PM10) exposure during the period of 'at risk' of pregnancy was assessed by months. An accelerated failure model was used to elucidate the association between monthly time-varying PM exposure and TTP. Subsequently, we estimated the prolonged TTP attributable to PM exposures above the World Health Organization (WHO)'s recommended air quality level in 2021.

RESULTS

Within the study regions, median TTP ranged from 6.90 (95 % CI 6.02-7.87) months in Latin America & Caribbean to 10.29 (95 % CI 9.28-11.36) months in East Asia & Pacific, with corresponding infertility prevalence varying from 33 % (95 % CI 29 %-36 %) to 44 % (95 % CI 41 %-48 %). Our estimations indicated that TTP was 1.08 (95 % CI: 0.99-1.18), 1.12 (95 % CI 1.06-1.19), and 1.05 (95 % CI 1.03-1.07) times longer for every 10 μg/m3 increment in PM1, PM2.5, and PM10, respectively. The prolonged TTP attributable to PM exposures surpassing the WHO guideline ranged from 0.11 to 2.81 months across the studied regions.

DISCUSSION

Ambient particulate matter is identified as a potential contributing factor to impaired fecundity in general population of LMICs. The findings underscore the importance of coordinated efforts to control ambient air pollution to mitigate the risk of fecundity reduction among the general population.

Against age limits for men in reproductive care

Almost all countries and fertility clinics impose age limits on women who want to become pregnant through Assisted Reproductive Technologies (ART). Age limits for aspiring fathers, however, are much less common and remain a topic of debate. This article departs from the principle of reproductive autonomy and a conditional positive right to receive ART, and asks whether there are convincing arguments to also impose age limits on aspiring fathers. After considering three consequentialist approaches to justifying age limits for aspiring fathers, we take in a concrete normative stance by concluding that those are not strong enough to justify such cut-offs. We reinforce our position by drawing a comparison between the case of a 39-year-old woman who wants to become a single mother via a sperm donor on the one hand, and on the other hand the same woman who wants to have a child with a 64-year-old man who she loves and who is willing to care for the child as long as he is able to. We conclude that, as long as appropriate precautions are taken to protect the welfare of the future child, couples who want to receive fertility treatment should never be limited on the basis of the age of the (male) partner. An absence of age limits for men would respect the reproductive autonomy of both the man and the woman.

The use of preimplantation genetic testing for aneuploidy: a committee opinion

The use of preimplantation genetic testing for aneuploidy (PGT-A) in the United States has been increasing steadily. Moreover, the underlying technology used for 24-chromosome analysis continues to evolve rapidly. The value of PGT-A as a routine screening test for all patients undergoing in vitro fertilization has not been demonstrated. Although some earlier single-center studies reported higher live-birth rates after PGT-A in favorable-prognosis patients, recent multicenter, randomized control trials in women with available blastocysts concluded that the overall pregnancy outcomes via frozen embryo transfer were similar between PGT-A and conventional in vitro fertilization. The value of PGT-A to lower the risk of clinical miscarriage is also unclear, although these studies have important limitations. This document replaces the document of the same name, last published in 2018.

"I'm not your grandpa": Experiences of advanced age fathers raising their teenage children in Belgium, an interpretative phenomenological analysis

This study aims to gain more insight in the lived experience of men who became father at an advanced age (40 years or older). Advanced Parental Age (APA) is becoming an increasingly widespread phenomenon as the average age at which people have children has been increasing for decades now. However, the psychosocial dimension of APA-fatherhood in particular remains a highly understudied topic. This Interpretive Phenomenological Analysis presents findings from a qualitative interview study with seven men who fathered their (now teenage) children in their early 40s to early 50s. Interviews were semi-structured and focused on lived experiences of the participants and their normative stances regarding the topic of parenting at an advanced age. Three themes were identified: The fathers in our sample describe their APA as a result of life events rather than an intentional postponement. Second, they managed how they were perceived as APA-fathers by distancing themselves from 'too old' parents. However, these fathers did not perceive fatherhood at a younger age as better than their current APA. Three fathers, who also had an earlier fatherhood experience, provided a rich account of how they made sense of their fatherhood roles in both families. Third, the seven fathers encountered social stigma, leading to various coping strategies. These findings contribute to better understanding the psychosocial dimension of APA-fatherhood.

The paternal clock: Uncovering the consequences of advanced paternal age on sperm DNA fragmentation

The objective of the study was to investigate the relationship between advanced paternal age and sperm DNA fragmentation (SDF) levels, specifically identifying the age at which a significant increase in SDF occurs. This is a retrospective cohort study involving 4250 consecutive semen samples from patients presenting for infertility evaluation. Patients were stratified into seven age groups: < 26 (n = 36; 0.8 %), 26-30 (n = 500; 11.8 %), 31-35 (n = 1269; 29.9 %), 36-40 (n = 1268; 29.8 %), 41-45 (n = 732; 17.2 %), 46-50 (n = 304; 7.2 %), > 50 (n = 141; 3.3 %). The main outcome measures included comparing mean SDF levels throughout different age groups and assessing the prevalence of normal, intermediate, and high SDF among the age groups. A positive correlation was observed between paternal age and SDF (r = 0.17, p < 0.001). SDF remained relatively constant until the age of 35 but increased significantly beyond age 35. Mean SDF levels in the older age groups (36-40, 41-45, 46-50, and >50 years) were significantly higher than in the younger age groups (<26, 26-30, and 31-35 years) (p < 0.001). The prevalence of normal SDF was highest among the younger age groups, whereas the prevalence of high SDF was highest among the older age groups. Interestingly, the prevalence of intermediate SDF was relatively constant throughout the age groups (ranging between 29.8 % to 37.2 %). The increase in SDF after the age of 35 highlights the importance of considering male age in infertility evaluations. Assessing SDF in men over the age of 35 is crucial in couples seeking to conceive.

UroLift to preserve seminal parameters in young male with LUTS from BPH

PURPOSE

Prostatic urethral lift has been an effective ejaculation sparing treatment for benign prostatic hypertrophy. The aim of this study was to evaluate the effect on male semen parameters.

METHODS

Between July 2014 and January 2022, 20 young men with urinary symptoms of BPH, unresponsive to drug treatment and motivated to preserve ejaculation for eventual paternity, underwent UroLift. Semen analysis was performed before and 6 month after surgery with evaluation of pH, volume, sperm concentration, total motility, vitality and morphology according to WHO 2011. All underwent digital rectal examination, transrectal prostate ultrasound to measure prostate volume, PSA, uroflowmetry, cystoscopy and urodynamics test if necessary. Objective and subjective urinary function was scheduled at 1, 3, 6, 12 month than yearly with UFM, IPSS, IIEF-5, and MSHQ-EjD-SF.

RESULTS

At a mean follow-up of 36 month (range 12 to 63), no retroejaculation or changes in seminal parameters occurred. Mean age was 44.5 (range 36.5 to 48) years. Mean operative time was 15 (range 10 to 20) min and 2.5 (range 2 to 4) implants per patients were used. At 6 month there were no difference in terms of total sperm count, volume, pH, motility, vitality, morphology, liquefaction, leucocytes (p = 0.9; p = 0.8; p = 0.7; p = 1; p = 1; p = 1; p = 0,2; p = 0.5). At last, Q-max increased by 64.4% (p = 0.001), post-void residual volume decreased by 66.6% (p = 0.016), and IPSS decreased by 60% (p < 0.001). IIEF and MSHQ-EjD-SF were preserved (p = 0.14, p = 0.4).

CONCLUSIONS

UroLift appears safe technique to correct LUTS from BPH in young men desirous to preserve seminal analysis.

Maternal age is related to offspring DNA methylation: A meta-analysis of results from the PACE consortium

Worldwide trends to delay childbearing have increased parental ages at birth. Older parental age may harm offspring health, but mechanisms remain unclear. Alterations in offspring DNA methylation (DNAm) patterns could play a role as aging has been associated with methylation changes in gametes of older individuals. We meta-analyzed epigenome-wide associations of parental age with offspring blood DNAm of over 9500 newborns and 2000 children (5-10 years old) from the Pregnancy and Childhood Epigenetics consortium. In newborns, we identified 33 CpG sites in 13 loci with DNAm associated with maternal age (PFDR < 0.05). Eight of these CpGs were located near/in the MTNR1B gene, coding for a melatonin receptor. Regional analysis identified them together as a differentially methylated region consisting of 9 CpGs in/near MTNR1B, at which higher DNAm was associated with greater maternal age (PFDR = 6.92 × 10-8) in newborns. In childhood blood samples, these differences in blood DNAm of MTNR1B CpGs were nominally significant (p < 0.05) and retained the same positive direction, suggesting persistence of associations. Maternal age was also positively associated with higher DNA methylation at three CpGs in RTEL1-TNFRSF6B at birth (PFDR < 0.05) and nominally in childhood (p < 0.0001). Of the remaining 10 CpGs also persistent in childhood, methylation at cg26709300 in YPEL3/BOLA2B in external data was associated with expression of ITGAL, an immune regulator. While further study is needed to establish causality, particularly due to the small effect sizes observed, our results potentially support offspring DNAm as a mechanism underlying associations of maternal age with child health.

Machine learning-enhanced noninvasive prenatal testing of monogenic disorders

OBJECTIVE

Single-nucleotide variants (SNVs) are of great significance in prenatal diagnosis as they are the leading cause of inherited single-gene disorders (SGDs). Identifying SNVs in a non-invasive prenatal screening (NIPS) scenario is particularly challenging for maternally inherited SNVs. We present an improved method to predict inherited SNVs from maternal or paternal origin in a genome-wide manner.

METHODS

We performed SNV-NIPS based on the combination of fragments of cell free DNA (cfDNA) features, Bayesian inference and a machine-learning (ML) prediction refinement step using random forest (RF) classifiers trained on millions of non-pathogenic variants. We next evaluate the real-world performance of our refined method in a clinical setting by testing our models on 16 families with singleton pregnancies and varying fetal fraction (FF) levels, and validate the results over millions of inherited variants in each fetus.

RESULTS

The average area under the ROC curve (AUC) values are 0.996 over all families for paternally inherited variants, 0.81 for the challenging maternally inherited variants, 0.86 for homozygous biallelic variants and 0.95 for compound heterozygous variants. Discriminative AUCs were achieved even in families with a low FF. We further investigate the performance of our method in correctly predicting SNVs in coding regions of clinically relevant genes and demonstrate significantly improved AUCs in these regions. Finally, we focus on the pathogenic variants in our cohort and show that our method correctly predicts if the fetus is unaffected or affected in all (10/10, 100%) of the families containing a pathogenic SNV.

CONCLUSIONS

Overall, we demonstrate our ability to perform genome-wide NIPS for maternal and homozygous biallelic variants and showcase the utility of our method in a clinical setting.

Sociodemographic Trends and Perinatal Outcomes in Fathers 50 Years and Older

Importance

The age of fathers at childbirth is rising, with an increasing number of births attributed to older fathers. While the impact of advanced paternal age has been documented, sociodemographic data about fathers aged 50 years and older remain scarce.

Objectives

To explore sociodemographic and temporal trends among the oldest US fathers (age ≥50 years) and their associations with perinatal outcomes.

Design, Setting, and Participants

This retrospective cross-sectional study included data from all US births from 2011 to 2022 using the National Vital Statistics System. Data were analyzed from August 2023 and May 2024.

Exposures

Reported paternal age at childbirth.

Main Outcomes and Measures

Outcomes of interest were sociodemographic factors, temporal trends in older fatherhood, and perinatal outcomes, including preterm birth, low birth weight, gestational diabetes, gestational hypertension, assisted reproductive technology (ART), rates of maternal primiparity, and the infant sex ratio.

Results

From 2011 to 2022, the US recorded 46 195 453 births, with an overall mean (SD) paternal age of 31.5 (6.8) years and 484 507 (1.1%) involving fathers aged 50 years or older, 47 785 (0.1%) aged 60 years or older, and 3777 (0.008%) aged 70 years or older. Births to fathers aged 50 years or older increased from 1.1% in 2011 to 1.3% in 2022 (P for trend < .001). Fathers aged 50 years or older were more diverse, with variations in educational achievement and race and ethnicity. Marital status and maternal racial and ethnic and educational backgrounds also varied by paternal age and race. Despite controlling for maternal age and other sociodemographic and perinatal factors, every 10-year increase in paternal age was consistently associated with greater use of ART (eg, age 50-59 years: adjusted odds ratio [aOR], 2.23; 95% CI, 2.19-2.27), higher likelihood of first maternal birth (eg, age 50-59 years: aOR, 1.16; 95% CI, 1.15-1.17), and increased risks of preterm birth (eg, age 50-59 years: aOR, 1.16; 95% CI, 1.15-1.18) and low birth weight (eg, age 50-59 years: aOR, 1.14; 95% CI, 1.13-1.15) compared with fathers aged 30 to 39 years. No significant changes in the infant sex ratio were observed, except among fathers aged 70 years or older (aOR, 0.92; 95% CI, 0.86-0.99) and 75 years or older (aOR, 0.84; 95% CI, 0.73-0.97), who showed a decreased likelihood of having male offspring.

Conclusions and Relevance

In this cross-sectional study of all US births from 2011 to 2022, the percentage attributed to older fathers, while small, increased. Notable variations in paternal and maternal race and education were identified. Older fatherhood was associated with increased ART use, first-time maternal births, adverse perinatal outcomes, and altered sex ratio. Further research of this population is crucial for improving patient counseling and family planning.

The current 'dramatically' high paternal ages at childbirth are not unprecedented

There is strong individual-level evidence that late fatherhood is related to a wide range of health disorders and conditions in offspring. Over the last decades, mean paternal ages at childbirth have risen drastically. This has alarmed researchers from a wide range of fields. However, existing studies have an important shortcoming in that they lack a long-term perspective. This article is a step change in providing such a long-term perspective. We unveil that in many countries the current mean paternal ages at childbirth and proportions of fathers of advanced age at childbirth are not unprecedented. Taking the detected U-shaped trend pattern into account, we discuss individual- and population-level implications of the recent increases in paternal ages at childbirth and highlight important knowledge gaps. At the individual level, some of the biological mechanisms that are responsible for the paternal age-related health risk might, at least to some degree, be counterbalanced by various social factors. Further, how these individual-level effects are linked to population health and human cognitive development might be influenced by various factors, including technical advances and regulations in prenatal diagnostics.

Identification of sensitive endpoints for the assessment of phthalates-induced reproductive and developmental toxicity: A literature mining study

Dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP), two common types of phthalates, are known to cause reproductive and developmental toxicity in animals and humans. The reference doses (RfD) of DBP and DEHP should be determined by sensitive endpoints. We here aimed to identify sensitive endpoints for DBP- and DEHP-induced such toxicity using published literatures. By examining the impacts of maternal exposure to DBP or DEHP on anogenital distance (AGD) and semen quality of offspring, we discovered that DBP or DEHP caused AGD decline in boys but increase in girls with DBP being more potent and the first 14weeks of pregnancy being more susceptible, suggesting a chemical- and time-dependent phenomenon. We also identified AGD shortening and total sperm count reduction as two sensitive endpoints for DBP- or DEHP-induced reproductive and developmental toxicity, respectively. Based upon these two endpoints and the employment of the Bayesian benchmark dose approach with an uncertainty factor of 3,000, we estimated the RfD values of DBP and DEHP were 15 μg/kg/day and 36 μg/kg/day, respectively. Thus, we uncover previously unrecognized phenomena of DBP- or DEHP-induced reproductive and developmental toxicity and establish new and comparable or more conservative RfDs for the risk assessment of phthalates exposure in humans.

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.

The Correlation of Paternal Age on Semen Parameters in Assisted Reproduction: A Retrospective Study in Qassim, Saudi Arabia

INTRODUCTION

In the past, fertility concerns have predominantly revolved around the effect of a woman's age on the quality of her eggs and the success of her pregnancy. While men generally retain their ability to father children throughout their lives, there is evidence suggesting a decline in natural conception rates as paternal age increases. A growing body of research indicates a potential link between advanced paternal age (APA) and various adverse outcomes, including changes in sperm genetics, reduced conception rates, higher rates of miscarriage, lower live birth rates, and even long-term health consequences in offspring. However, it remains unclear whether there is an association between APA and the effectiveness of assisted reproductive technology (ART). This study aims to shed light on the relationship between APA and semen parameters.

METHODOLOGY

This is a retrospective, descriptive study analyzing data from electronic medical records of men undergoing ART at a fertility clinic in Saudia Arabia (2017-2022). Men aged 21-60 with at least one semen analysis and no missing data/hormonal treatment were included. Data on age and semen parameters (count, motility, and morphology) were extracted and analyzed using Jeffreys's Amazing Statistics Program (JASP; University of Amsterdam, Amsterdam, Netherlands) (descriptive statistics, Spearman's rank correlation).

RESULTS

Analysis of 1506 men undergoing ART revealed a mean age of 37 years (SD=6.94) and a mean sperm count of 55.0 million/mL (SD=46.05). The correlation between age and sperm count indicates a minimal association (r=0.075, p<0.01); moderate positive correlations were observed between sperm count and motility (r=0.406); count and morphology (r=0.543); and motility and morphology (r=0.458).

CONCLUSION

Age may not be a major factor in overall sperm parameters for this population, but a strong positive correlation was observed between sperm count, motility, and normal morphology. These findings suggest that these semen parameters are interconnected, with higher sperm counts potentially indicating better overall sperm quality.

Coevolution of longevity and female germline maintenance

An often-overlooked aspect of life-history optimization is the allocation of resources to protect the germline and secure safe transmission of genetic information. While failure to do so renders significant fitness consequences in future generations, germline maintenance comes with substantial costs. Thus, germline allocation should trade off with other life-history decisions and be optimized in accordance with an organism's reproductive schedule. Here, we tested this hypothesis by studying germline maintenance in lines of seed beetle, selected for early (E) or late (L) reproduction for 350 and 240 generations, respectively. Female animals provide maintenance and screening of male gametes in their reproductive tract and oocytes. Here, we reveal the ability of young and aged E- and L-females to provide this form of germline maintenance by mating them to males with ejaculates with artificially elevated levels of protein and DNA damage. We find that germline maintenance in E-females peaks at young age and then declines, while the opposite is true for L-females, in accordance with the age of reproduction in the respective regime. These findings identify the central role of allocation to secure germline integrity in life-history evolution and highlight how females can play a crucial role in mitigating the effects of male germline decisions on mutation rate and offspring quality.

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.

Associations of parental age at pregnancy with adolescent cognitive development and emotional and behavioural problems: a birth cohort in rural Western China

BACKGROUND

The relationship between parental age at pregnancy and offspring development in low- and middle-income countries remains unclear. We aimed to examine the associations of parental age at pregnancy with adolescent development in rural China.

METHODS

We conducted a prospective birth cohort study of offspring born to pregnant women who participated in an antenatal micronutrient supplementation trial in rural Western China. Adolescent cognitive development and emotional and behavioural problems were assessed by using the Wechsler Intelligence Scale for Children-IV and the Youth Self-Report-2001, respectively. After accounting for the possible nonlinear relationships, we examined the linear associations between parental age (in years) at pregnancy and scores of adolescent cognitive development and emotional and behavioural problems by performing generalized estimating equations.

RESULTS

Among 1897 adolescents followed from birth to early adolescence, 59.5% were male with a mean age of 11.8 (standard deviation (SD): 0.8) years. The mean ages of mothers and fathers at pregnancy were 24.6 (SD: 4.4) and 27.9 (SD: 4.1) years old, respectively. All the P values of the nonlinear terms between parental age and adolescent development in all domains were greater than 0.05. Each one-year increase in maternal age at pregnancy was associated with a 0.29-point (95% confidence interval (CI) 0.06, 0.52) increase in the full-scale intelligence quotient in early adolescence. After parental age was categorized into quartiles, the total behavioural problem scores of adolescents with fathers with an age in the fourth quartile (Q4) were 6.71 (95% CI 0.86, 12.57) points higher than those of adolescents with fathers with an age in the first quartile (Q1), with a linear trend P value of 0.01. Similarly, higher scores (worse behavioural problems) were observed for internalizing behavioural problems and other emotional and behavioural symptoms related to anxiety, withdrawal, social problems, thought problems and aggressive behaviour.

CONCLUSIONS

At conception, older maternal age was independently linked to better adolescent cognitive development, whereas advanced paternal age was independently associated with a greater risk of adolescent emotional and behavioral problems. These findings suggest that public health policies targeting an optimal parental age at pregnancy should be developed in the context of offspring developmental consequences.

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.

Correlates of Sexual Behavior Across Fatherhood Status: Finding From the National Longitudinal Study of Adolescent to Adult Health (Add Health), 2016-2018

Amid national trends in postponed parenthood and more diverse family structures, the fatherhood identity may be important to men's sexual behaviors. This study examined factors associated with reports of consistent contraceptive use and multiple sexual partners across fatherhood status. Using public data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), Wave V (2016-2018), two sexual behaviors were examined among 1,163 men aged 32 to 42 years. Outcomes were two binary indicators: consistent contraceptive use with partner and having multiple (≥2) sexual partners in the past year. Fatherhood status was categorized as nonfather, resident father, and nonresident father. Demographic (e.g., race/ethnicity, education, income, and relationship type) and health-related (e.g., drinking, perceived stress, depressive symptoms, and insurance status) factors were considered. Logistic regression analysis produced odds ratios and 95% confidence intervals and were stratified by fatherhood categories. In the sample, 72% of men were resident fathers, 10% were nonresident fathers, and 18% were nonfathers; 28% reported consistent contraceptive use and 16% reported multiple sexual partners. For nonfathers, relationship type and race were associated with reporting multiple sexual partners. For resident fathers, relationship type was the crucial factor associated with consistent contraceptive use and reporting multiple sexual partners. In nonresident fathers, relationship type, education, and income were important factors to consistent contraceptive use and reporting multiple sexual partners. Key findings suggest that relationship type, income, and education are crucial factors to men's sexual behavior. Heterogeneous effects were observed across fatherhood status. This study adds to limited research on fatherhood and sexual behavior among men transitioning from young adulthood to middle age.

Frequency, morbidity and equity - the case for increased research on male fertility

Currently, most men with infertility cannot be given an aetiology, which reflects a lack of knowledge around gamete production and how it is affected by genetics and the environment. A failure to recognize the burden of male infertility and its potential as a biomarker for systemic illness exists. The absence of such knowledge results in patients generally being treated as a uniform group, for whom the strategy is to bypass the causality using medically assisted reproduction (MAR) techniques. In doing so, opportunities to prevent co-morbidity are missed and the burden of MAR is shifted to the woman. To advance understanding of men's reproductive health, longitudinal and multi-national centres for data and sample collection are essential. Such programmes must enable an integrated view of the consequences of genetics, epigenetics and environmental factors on fertility and offspring health. Definition and possible amelioration of the consequences of MAR for conceived children are needed. Inherent in this statement is the necessity to promote fertility restoration and/or use the least invasive MAR strategy available. To achieve this aim, protocols must be rigorously tested and the move towards personalized medicine encouraged. Equally, education of the public, governments and clinicians on the frequency and consequences of infertility is needed. Health options, including male contraceptives, must be expanded, and the opportunities encompassed in such investment understood. The pressing questions related to male reproductive health, spanning the spectrum of andrology are identified in the Expert Recommendation.

Parental age effects and Rett syndrome

Rett syndrome (RTT) is a progressive neurodevelopmental disorder, and pathogenic Methyl-CpG-binding Protein 2 (MECP2) variants are identified in >95% of individuals with typical RTT. Most of RTT-causing variants in MECP2 are de novo and usually on the paternally inherited X chromosome. While paternal age has been reported to be associated with increased risk of genetic disorders, it is unknown whether parental age contributes to the risk of the development of RTT. Clinical data including parental age, RTT diagnostic status, and clinical severity are collected from 1226 participants with RTT and confirmed MECP2 variants. Statistical analyses are performed using Student t-test, single factor analysis of variance (ANOVA), and multi-factor regression. No significant difference is observed in parental ages of RTT probands compared to that of the general population. A small increase in parental ages is observed in participants with missense variants compared to those with nonsense variants. When we evaluate the association between clinical severity and parental ages by multiple regression analysis, there is no clear association between clinical severity and parental ages. Advanced parental ages do not appear to be a risk factor for RTT, and do not contribute to the clinical severity in individuals with RTT.

Social network investment of men: Cross-sectional and longitudinal associations with mental health problems

Internationally, there is growing attention on links between social isolation and mental health problems. Here, we use unique Australian longitudinal data to investigate associations between adult men's (n = 507; age M = 29.90, SD = 1.31) social network investments and their concurrent and subsequent mental health problems. In linear regressions, using generalised estimating equations (GEEs), we examined associations between social network investment (time with friends, network size and various activities with friends) and mental health symptoms (depression, anxiety and stress) across five timepoints. Models were adjusted for waves of outcome and potential confounders. Cross-sectionally, each social network investment variable, except for drinking with friends, was negatively associated with depressive symptoms. Men's extended friendship network size and sharing a meal with friends were negatively associated with concurrent anxiety and stress. Time spent and physical activity with friends was also negatively associated with concurrent stress. In longitudinal analyses, after adjusting for prior depressive symptoms, only the number of friends in close and extended networks remained protective against depressive symptoms 1 year later. Results did not differ by fatherhood or relationship status. Programs designed to strengthen men's investment in social networks are recommended to reduce men's depressive symptoms.

The association between parental age differences and perinatal outcomes

STUDY QUESTION

Are there significant associations existing between parental age differences and adverse perinatal outcomes?

SUMMARY ANSWER

Large differences in parental age are associated with adverse perinatal outcomes, particularly with older mothers paired with younger fathers.

WHAT IS KNOWN ALREADY

The association between advanced maternal age and perinatal outcomes is well-documented with women over 35 years showing an increased risk of several adverse outcomes. Other studies have identified potential associations between advanced paternal age and adverse perinatal outcomes.

STUDY DESIGN, SIZE, DURATION

A historical (retrospective) cohort analysis was performed utilizing a multivariable logistic regression model to evaluate the association between varying differences in parental age and adverse perinatal outcomes while controlling for demographic and health-related covariates. Data were compiled from the National Vital Statistics System for 20 613 704 births between 2012 and 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Parental age differences, categorized into eleven 4-year intervals, were stratified by seven maternal age categories and evaluated for their associations with adverse perinatal outcomes. Main outcome measures included low birth weight, very low birth weight, preterm birth, very preterm birth, small size for gestational age, low 5-min appearance, pulse, grimace, activity, and respiration score, congenital defects, and chromosomal anomalies.

MAIN RESULTS AND THE ROLE OF CHANCE

Increased parental age differences, in either direction, were associated with significant risks for all adverse outcomes, aside from congenital defects, even when controlling for maternal age. Restricting maternal age to the reference range of 25-29 years, infants born to fathers aged 9-12 years younger (n = 3773) had 27% (odds ratio (OR) 1.27, 95% CI, 1.17-1.37) higher odds of having any adverse perinatal outcome. Infants born to fathers aged >16 years older (n = 98 555) had 14% (OR 1.14, 95% CI, 1.12-1.16) higher odds of having any adverse perinatal outcome.

LIMITATIONS, REASONS FOR CAUTION

Data extracted from US birth certificates may be compromised by errors in reporting or documentation. Information regarding the mother's socioeconomic status was estimated using proxy variables and may be susceptible to uncontrolled factors. Use of a pre-compiled dataset may potentially exclude additional maternal comorbidities that could impact perinatal outcomes.

WIDER IMPLICATIONS OF FINDINGS

Older mothers paired with younger fathers demonstrated the highest risk, even when maternal age was below the threshold of 35 years. For the clinical setting, parental age differences should be considered alongside maternal and paternal age when assessing risks of adverse perinatal outcomes for potential parents. This is particularly relevant for older women with younger male partners as this may exacerbate the impact of advanced maternal age.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by the NIH Research Fellowship T35 Training Grant. There are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Paternal age and perinatal outcomes: an observational study

OBJECTIVES

The study's primary aim was to examine the relationship between paternal age and perinatal outcomes.

METHODS

This study used data from two hospital birth registries to examine the association between paternal age and adverse perinatal outcomes. The sample included all live singleton births between 2010 and 2022. The primary exposure was paternal age, and the following perinatal outcomes were considered: mode of conception, mode of delivery, pregnancy complications, and neonatal outcomes.

RESULTS

A total of 15,232 pregnant women were considered. Maternal and paternal ages were 31.9 ± 5.3 and 36.5 ± 6.5 years, respectively. Independent of maternal, paternal age was associated with lower odds of spontaneous conceptions (OR 0.930, 95 % CI 0.968/0.993; p=0.003) and higher odds of intracytoplasmatic sperm injection (OR 1.054, 95 % CI 1.045/1.062; p=0.0001), respectively. In contrast to maternal age, paternal age decreased the odds of any (OR 0.922, 95 % CI 0.985/0.999; p=0.032) and urgent/emergent (OR 0.984, 95 % CI 0.975/0.993; p=0.0001) cesarean delivery. Paternal age did not affect the gestation length, placental or neonatal weight, blood loss during delivery, and neonatal 5th-minute Apgar score.

CONCLUSIONS

Paternal age is associated with perinatal outcomes. These findings suggest that advanced paternal age may have implications for reproductive counseling and prenatal care.

The impact of paternal age on cumulative assisted reproductive technology outcomes

Objective

To investigate the impact of paternal age on cumulative live birth rate in ART.

Design

Retrospective single-center cohort study.

Patients

All female patients aged 18-43 years and male patients aged 18-60 years, who performed their first ART cycle between January 2018 and December 2020, were included.

Main outcome measures

The primary outcome, cumulative live birth rate (cLBR), was estimated following fresh or frozen embryo transfers issued from an ART cycle. Secondary outcomes included the cumulative pregnancy rate (cPR) and miscarriage rate. Subgroup analyzes were performed as follows: men <45 and ≥ 45; female <35, 35-38, and > 38 years.

Results

A total of 2,358 couples were included in this study. The sperm quantity of male patients within both age groups was divided in two groups: normal and abnormal, which were found to be in significantly equal proportions. There were significantly fewer current smokers in the male group ≥45. The cPR was 0.5301 in the group <45 and 0.3111 in the group ≥45, with a p-value <0.001. Analysis according to the female age revealed that, in the female group >38, the cLBR rate was 0.26 for men <45 and 0.19 for men ≥45, with a p-value of 0.061. Additionally, the cPR was 0.34 in the male group <45 and 0.21 in the group ≥45, with a p-value <0.001. In the female group between 35 and 38 years of age, the cLBR was 0.44 in the male group <45 and 0.3 in the male group ≥45, with a p-value of 0.031. The cPR was 0.49 in the male group <45 and 0.34 in the group ≥45, p = 0.036. Within the female group <35, we observed non-significant results. The miscarriage rate results were not significantly different for women ≤38.

Conclusion

According to the results from our study, male age ≥ 45 has a significant impact on cumulative ART outcomes.

Mouse Tspyl5 promotes spermatogonia proliferation through enhancing Pcna-mediated DNA replication

CONTEXT

The human TSPY1 (testis-specific protein, Y-linked 1) gene is critical for spermatogenesis and male fertility. However, there have been difficulties with studying the mechanism underlying its function, partly due to the presence of the Tspy1 pseudogene in mice.

AIMS

TSPYL5 (TSPY-like 5), an autosomal homologous gene of TSPY1 showing a similar expression pattern in both human and mouse testes, is also speculated to play a role in male spermatogenesis. It is beneficial to understand the role of TSPY1 in spermatogenesis by investigating Tspyl5 functions.

METHODS

Tspyl5 -knockout mice were generated to investigate the effect of TSPYL5 knockout on spermatogenesis.

KEY RESULTS

Tspyl5 deficiency caused a decline in fertility and decreased the numbers of spermatogonia and spermatozoa in aged male mice. Trancriptomic detection of spermatogonia derived from aged Tspyl5 -knockout mice revealed that the Pcna -mediated DNA replication pathway was downregulated. Furthermore, Tspyl5 was proven to facilitate spermatogonia proliferation and upregulate Pcna expression by promoting the ubiquitination-degradation of the TRP53 protein.

CONCLUSIONS

Our findings suggest that Tspyl5 is a positive regulator for the maintenance of the spermatogonia pool by enhancing Pcna -mediated DNA replication.

IMPLICATIONS

This observation provides an important clue for further investigation of the spermatogenesis-related function of TSPY1 .

Racial and ethnic and socioeconomic disparities in childhood cancer incidence trends in the United States, 2000-2019

BACKGROUND

Population-based surveillance of pediatric cancer incidence trends is critical to determine high-risk populations, drive hypothesis generation, and uncover etiologic heterogeneity. We provide a comprehensive update to the current understanding of pediatric cancer incidence trends by sex, race and ethnicity, and socioeconomic status (SES).

METHODS

The Surveillance, Epidemiology, and End Results 22 data (2000-2019) was used to summarize age-adjusted incidence rates for children and adolescents aged 0-19 years at diagnosis. The annual percentage change (APC) and 95% confidence interval (CI) were estimated to evaluate incidence trends by sex, race and ethnicity, and SES overall and for cancer subtypes. Tests of statistical significance were 2-sided.

RESULTS

Substantial variation was observed overall and for several histologic types in race and ethnicity- and SES-specific rates. Overall, we observed a statistically significant increase in incidence rates (APC = 0.8%, 95% CI = 0.6% to 1.1%). All race and ethnic groups saw an increase in incidence rates, with the largest occurring among non-Hispanic American Indian and Alaska Native children and adolescents (APC = 1.7%, 95% CI = 0.5% to 2.8%) and the smallest increase occurring among non-Hispanic White children and adolescents (APC = 0.7%, 95% CI = 0.5% to 1.0%). The lowest SES quintiles saw statistically significant increasing trends, while the highest quintile remained relatively stable (quintile 1 [Q1] APC = 1.6%, 95% CI = 0.6% to 2.6%; quintile 5 [Q5] APC = 0.3%, 95% CI = -0.1% to 0.7%).

CONCLUSIONS

Childhood cancer incidence is increasing overall and among every race and ethnic group. Variation by race and ethnicity and SES may enable hypothesis generation on drivers of disparities observed.

A DNA Methylation Perspective on Infertility

Infertility affects a significant number of couples worldwide and its incidence is increasing. While assisted reproductive technologies (ART) have revolutionized the treatment landscape of infertility, a significant number of couples present with an idiopathic cause for their infertility, hindering effective management. Profiling the genome and transcriptome of infertile men and women has revealed abnormal gene expression. Epigenetic modifications, which comprise dynamic processes that can transduce environmental signals into gene expression changes, may explain these findings. Indeed, aberrant DNA methylation has been widely characterized as a cause of abnormal sperm and oocyte gene expression with potentially deleterious consequences on fertilization and pregnancy outcomes. This review aims to provide a concise overview of male and female infertility through the lens of DNA methylation alterations.

Building a family at advanced parental age: a systematic review on the risks and opportunities for parents and their offspring

STUDY QUESTION

What is the existing empirical literature on the psychosocial health and wellbeing of the parents and offspring born at an advanced parental age (APA), defined as 40 years onwards?

SUMMARY ANSWER

Although the studies show discrepancies in defining who is an APA parent and an imbalance in the empirical evidence for offspring, mothers, and fathers, there is a drive towards finding psychotic disorders and (neuro-)developmental disorders among the offspring; overall, the observed advantages and disadvantages are difficult to compare.

WHAT IS KNOWN ALREADY

In many societies, children are born to parents at advanced ages and there is rising attention in the literature towards the consequences of this trend.

STUDY DESIGN SIZE DURATION

The systematic search was conducted in six electronic databases (PubMed including Medline, Embase, Scopus, PsycInfo, CINAHL, and SocINDEX) and was limited to papers published between 2000 and 2021 and to English-language articles. Search terms used across all six electronic databases were: ('advanced parental age' OR 'advanced maternal age' OR 'advanced paternal age' OR 'advanced reproductive age' OR 'late parent*' OR 'late motherhood' OR 'late fatherhood') AND ('IVF' OR 'in vitro fertilization' OR 'in-vitro-fertilization' OR 'fertilization in vitro' OR 'ICSI' OR 'intracytoplasmic sperm injection' OR 'reproductive techn*' OR 'assisted reproductive technolog*' OR 'assisted reproduction' OR 'assisted conception' OR 'reproduction' OR 'conception' OR 'birth*' OR 'pregnan*') AND ('wellbeing' OR 'well-being' OR 'psycho-social' OR 'social' OR 'ethical' OR 'right to reproduce' OR 'justice' OR 'family functioning' OR 'parental competenc*' OR 'ageism' OR 'reproductive autonomy' OR 'outcome' OR 'risk*' OR 'benefit*').

PARTICIPANTS/MATERIALS SETTING METHODS

The included papers were empirical studies in English published between 2000 and 2021, where the study either examined the wellbeing and psychosocial health of parents and/or their children, or focused on parental competences of APA parents or on the functioning of families with APA parents. A quality assessment of the identified studies was performed with the QATSDD tool. Additionally, 20% of studies were double-checked at the data extraction and quality assessment stage to avoid bias. The variables sought were: the geographical location, the year of publication, the methodological approach, the definitions of APA used, what study group was at the centre of the research, what research topic was studied, and what advantages and disadvantages of APA were found.

MAIN RESULTS AND THE ROLE OF CHANCE

A total number of 5403 articles were identified, leading to 2543 articles being included for title and abstract screening after removal of duplicates. This resulted in 98 articles included for a full-text reading by four researchers. Ultimately, 69 studies were included in the final sample. The key results concerned four aspects relevant to the research goals. (i) The studies showed discrepancies in defining who is an APA parent. (ii) There was an imbalance in the empirical evidence produced for different participant groups (mothers, fathers, and offspring), with offspring being the most studied study subjects. (iii) The research topics studied underlined the increased risks of neuro-developmental and psychotic disorders among offspring. (iv) The observed advantages and disadvantages were varied and could not be compared, especially for the offspring of APA parents.

LIMITATIONS REASONS FOR CAUTION

Only English-language studies, published between 2000 and 2021, found in the above-mentioned databases were considered for this review.

WIDER IMPLICATIONS OF THE FINDINGS

More research is necessary to understand the risks and benefits of building a family at an APA for the offspring when they reach adulthood. Furthermore, studies that explore the perspective of older fathers and older parents from non-Western societies would be highly informative.

STUDY FUNDING/COMPETING INTERESTS

The writing of this manuscript was permitted by financial support provided by the Swiss National Science Foundation (Weave/Lead Agency funding program, grant number 10001AL_197415/1, project title 'Family Building at Advanced Parental Age: An Interdisciplinary Approach'). The funder had no role in the drafting of this manuscript and the views expressed therein are those of the authors. The authors have no conflicts of interest.

REGISTRATION NUMBER

This systematic review is registered in Prospero: CRD42022304564.

Age-Dependent Alterations in Semen Parameters and Human Sperm MicroRNA Profile

The trend to delay parenthood is increasing, impacting fertility and reproductive outcomes. Advanced paternal age (APA), defined as men's age above 40 years at conception, has been linked with testicular impairment, abnormal semen parameters, and poor reproductive and birth outcomes. Recently, the significance of sperm microRNA for fertilization and embryonic development has emerged. This work aimed to investigate the effects of men's age on semen parameters and sperm microRNA profiles. The ejaculates of 333 Portuguese men were collected between 2018 and 2022, analyzed according to WHO guidelines, and a density gradient sperm selection was performed. For microRNA expression analysis, 16 normozoospermic human sperm samples were selected and divided into four age groups: ≤30, 31-35, 36-40, and >40 years. microRNA target genes were retrieved from the miRDB and TargetScan databases and Gene Ontology analysis was performed using the DAVID tool. No significant correlation was found between male age and conventional semen parameters, except for volume. Fifteen differentially expressed microRNAs (DEMs) between groups were identified. Enrichment analysis suggested the involvement of DEMs in the sperm of men with advanced age in critical biological processes like embryonic development, morphogenesis, and male gonad development. Targets of DEMs were involved in signaling pathways previously associated with the ageing process, including cellular senescence, autophagy, insulin, and mTOR pathways. These results suggest that although conventional semen parameters were not affected by men's age, alterations in microRNA regulation may occur and be responsible for poor fertility and reproductive outcomes associated with APA.

From Diagnosis to Treatment: Comprehensive Care by Reproductive Urologists in Assisted Reproductive Technology

Infertility is a global health concern, with male factors playing an especially large role. Unfortunately, however, the contributions made by reproductive urologists in managing male infertility under assisted reproductive technology (ART) often go undervalued. This narrative review highlights the important role played by reproductive urologists in diagnosing and treating male infertility as well as any barriers they face when providing services. This manuscript presents a comprehensive review of reproductive urologists' role in managing male infertility, outlining their expertise in diagnosing and managing male infertility as well as reversible causes and performing surgical techniques such as sperm retrieval. This manuscript investigates the barriers limiting urologist involvement such as limited availability, awareness among healthcare professionals, and financial constraints. This study highlights a decrease in male fertility due to lifestyle factors like sedentary behavior, obesity, and substance abuse. It stresses the significance of conducting an evaluation process involving both male and female partners to identify any underlying factors contributing to infertility and to identify patients who do not require any interventions beyond ART. We conclude that engaging urologists more effectively in infertility management is key to optimizing fertility outcomes among couples undergoing assisted reproductive technology treatments and requires greater education among healthcare providers regarding the role urologists and lifestyle factors that could have an effect on male fertility.

Obstetrical and Perinatal Outcomes Are Not Associated with Advanced Paternal Age in IVF or ICSI Pregnancies with Autologous Oocytes

BACKGROUND

In recent years, there has been an evident delay in childbearing and concerns have been raised about whether this increase in age affects reproductive outcomes. This study aimed to evaluate the effect of paternal age on obstetrical and perinatal outcomes in couples undergoing in vitro fertilization or intracytoplasmic sperm injection using autologous sperm and oocytes.

METHODS

This retrospective study evaluated obstetrical and perinatal outcomes from 14,125 couples that were arbitrarily divided into three groups according to paternal age at conception: ≤30 (n = 1164), 31-40 (n = 11,668) and >40 (n = 1293). Statistics consisted of a descriptive analysis followed by univariate and multivariate models, using the youngest age group as a reference.

RESULTS

The study showed significantly longer pregnancies for the fathers aged 31-40 compared to ≤30 years. However, there were no significant differences for the type of delivery, gestational diabetes, anaemia, hypertension, delivery threat, premature rupture of membranes, preterm birth, very preterm birth, and the neonate's sex, weight, low birth weight, very low birth weight, length, cranial perimeter, Apgar score and neonatal intensive care unit admission.

CONCLUSION

Despite our promising results for older fathers, as paternal age was not associated with clinically relevant obstetrical and perinatal outcomes, future well-designed studies are necessary as it has been associated with other important disorders.

Male infertility

Clinical infertility is the inability of a couple to conceive after 12 months of trying. Male factors are estimated to contribute to 30-50% of cases of infertility. Infertility or reduced fertility can result from testicular dysfunction, endocrinopathies, lifestyle factors (such as tobacco and obesity), congenital anatomical factors, gonadotoxic exposures and ageing, among others. The evaluation of male infertility includes detailed history taking, focused physical examination and selective laboratory testing, including semen analysis. Treatments include lifestyle optimization, empirical or targeted medical therapy as well as surgical therapies that lead to measurable improvement in fertility. Although male infertility is recognized as a disease with effects on quality of life for both members of the infertile couple, fewer data exist on specific quantification and impact compared with other health-related conditions.

Human deleterious mutation rate implies high fitness variance, with declining mean fitness compensated by rarer beneficial mutations of larger effect

Each new human has an expected Ud = 2 - 10 new deleterious mutations. This deluge of deleterious mutations cannot all be purged, and therefore accumulate in a declining fitness ratchet. Using a novel simulation framework designed to efficiently handle genome-wide linkage disequilibria across many segregating sites, we find that rarer, beneficial mutations of larger effect are sufficient to compensate fitness declines due to the fixation of many slightly deleterious mutations. Drift barrier theory posits a similar asymmetric pattern of fixations to explain ratcheting genome size and complexity, but in our theory, the cause is Ud > 1 rather than small population size. In our simulations, Ud ~2 - 10 generates high within-population variance in relative fitness; two individuals will typically differ in fitness by 15-40%. Ud ~2 - 10 also slows net adaptation by ~13%-39%. Surprisingly, fixation rates are more sensitive to changes in the beneficial than the deleterious mutation rate, e.g. a 10% increase in overall mutation rate leads to faster adaptation; this puts to rest dysgenic fears about increasing mutation rates due to rising paternal age.

Intra-individual changes in sperm DNA fragmentation levels over short and long time periods

PURPOSE

We aimed to examine the longitudinal, intra-personal changes in DNA fragmentation index (DFI) over time.

METHODS

Men who performed at least two DFI measurements (using sperm chromatin structure assay (SCSA) between 2003 and 2019 were included in this study and allocated to groups by time between DFI tests: < 1 year, 1-3 years, 3-5 years, and > 5 years. An analysis of DFI change over time according to age groups was additionally performed. Regression models were developed to predict changes in DFI with time.

RESULTS

Overall, 225 patients had two or more DFI measurements done at least a month apart (mean of 586.7± 710.0 days). The < 1 year (n = 124) and 1-3 years (n = 68) groups demonstrated decreased DFI levels, while an increase in DFI was shown in 3-5 years (n = 21) and more than 5 years (n = 12) groups - 7.1 ± 14.9%, - 4.5 ± 13.4%, + 3.2 ± 8.4%, and + 10.8 ± 18.0%, respectively, p < 0.001). This trend was similarly shown in age subgroups of under 40 years and 40-50 years at baseline DFI. Linear regression models showed that the factors predictive of DFI increase are baseline DFI and > 3 years between DFI tests.

CONCLUSION

This study shows that DFI, in men being investigated for infertility, initially decreases in the first 3 years of follow-up, and then increases over time with the highest increase occurring after 5 years interval (an average increase of 10.8%). Testing infertile men's DFI levels at first evaluation may contribute to personalized consult regarding future reproductive outcomes.

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.

Highly Purified Human Menopausal Gonadotropin (HP-hMG) Versus Recombinant Follicle-Stimulating Hormone (rFSH) for Controlled Ovarian Stimulation in US Predicted High-Responder Patients: A Cost-Comparison Analysis

OBJECTIVES

Infertility imposes considerable clinical and economic burden, and the high costs of fertility care are a major barrier to payers. This study assessed the cost differences of highly purified human menopausal gonadotropin (HP-hMG) versus recombinant follicle stimulating hormone (rFSH) for controlled ovarian stimulation (COS) protocols in predicted high-responders from the US payer perspective.

METHODS

A discrete event simulation model was built to perform a cost-comparison analysis of HP-hMG versus rFSH in a cohort of predicted high-responders undergoing up to three embryo transfer cycles, informed by efficacy data from the MEGASET-HR trial. The model considered an event-based treatment pathway and transition probabilities were derived from MEGASET-HR. A variable time horizon was employed, and deterministic and probabilistic sensitivity analyses conducted.

RESULTS

Subjects undergoing COS with HP-hMG and rFSH demonstrated comparable live birth rates following three in vitro fertilization (IVF) cycles, with 161 live births with HP-hMG and 152 live births with rFSH, per 310 high-responders. The total cost saving per live birth in subjects receiving HP-hMG versus rFSH was US$3024. These cost savings were largely driven by the need for fewer embryo transfers to achieve similar efficacy outcomes and a reduced rate of ovarian hyperstimulation syndrome. Following deterministic sensitivity analysis, HP-hMG remained cost saving in all baseline parameter variations. No parameters led to rFSH providing cost savings when compared with HP-hMG.

CONCLUSION

Comparable clinical outcomes can be achieved at a lower cost when using HP-hMG versus rFSH based COS protocols in a cohort of predicted high-responders. Such cost savings may reduce the economic burden infertility currently presents to US healthcare providers and those seeking fertility care.

Understanding the age-related alterations in the testis-specific proteome

INTRODUCTION

Fertility rates in developing countries have declined over the past decades, and the trend of delayed fatherhood is rising as societies develop. The reasons behind the decline in male fertility with advancing age remain mysterious, making it a compelling and crucial area for further research. However, the limited number of studies dedicated to unraveling this enigma poses a challenge. Thus, our objective is to illuminate some of the upregulated and downregulated mechanisms in the male testis during the aging process.

AREAS COVERED

Herein, we present a critical overview of the studies addressing the alterations of testicular proteome through the aging process, starting from sexually matured young males to end-of-life-expectancy aged males. The comparative studies of the proteomic testicular profile of men with and without spermatogenic impairment are also discussed and key proteins and pathways involved are highlighted.

EXPERT OPINION

The difficulty of making age-comparative studies, especially of advanced-age study subjects, makes this topic of study quite challenging. Another topic worth mentioning is the heterogeneous nature and vast cellular composition of testicular tissue, which makes proteome data interpretation tricky. The cell type sorting and comorbidities testing in the testicular tissue of the studied subjects would help mitigate these problems.

Ascorbic acid is associated with favourable hormonal profiles among infertile males

Introduction

Infertility affects about 16% of North American couples, with the male factor contributing to ∼30% of cases. Reproductive hormones play an integral role in regulating the reproductive system and consequently, fertility. Oxidative stress reduces testosterone synthesis, and reduction in oxidative stress can improve hormone profiles. Ascorbic acid is a potent antioxidant that accounts for up to 65% of seminal antioxidant activity; however, its effects on reproductive hormones in humans are unknown.

Methods

The objective was to determine the association between serum ascorbic acid concentrations and male reproductive hormones. We conducted a cross-sectional study involving infertile males (n = 302) recruited from Mount Sinai Hospital, Toronto. Serum was analyzed for ascorbic acid, luteinizing hormone (LH), follicular stimulating hormone (FSH), total testosterone (TT), prolactin and estradiol. Statistical analyses included Spearman's rank correlations, linear regressions, logistic regressions, simple slope and Johnson-Neyman procedures.

Results

After adjusting for covariates, ascorbic acid was inversely associated with LH (P = 0.01). Ascorbic acid was positively associated with TT only among males over the age of 41.6 years (P = 0.01).

Discussion

Our findings show that ascorbic acid is associated with higher testosterone levels and improved androgenic status in infertile males, and some of the effects appear to be age dependent.

The psychosocial outcomes of older parenthood in early to mid-childhood: a mini-review

Recent decades have seen a global trend towards delaying parenthood, referred to as the 'postponement transition'. Whilst there is plentiful research regarding obstetric and paediatric outcomes related to delayed parenthood, relatively little is known about the psychosocial outcomes associated with advanced parental age during early and middle childhood. This mini-review examines the current literature regarding the psychosocial functioning of families headed by older parents. First, we give an overview of the literature that examines the psychological wellbeing of older first-time parents. We then review the literature regarding the quality of the parent-child relationship in older parent families. Finally, we discuss the psychosocial adjustment and cognitive development of children of older parents. We conclude with suggestions for future research avenues.

Parental Age and Childhood Risk for Cerebral Palsy in California

OBJECTIVE

To investigate the associations between maternal or paternal age at the time of delivery and offspring's risk for cerebral palsy (CP) in California.

STUDY DESIGN

We conducted a population-based, case-control study that included 8736 singleton CP cases and 90 250 singleton controls, matched by sex and birth year, selected from California birth certificate records from 1994 to 2010. We estimated OR and 95% CIs for CP diagnosis according to maternal and paternal age recorded on the birth certificates. Causal mediation analysis was performed to estimate direct and indirect effects of parental ages on CP with preterm delivery as a potential mediator.

RESULTS

Children born to younger mothers (≤19 years) or older mothers (35-39 years; ≥40 years) had a greater risk of CP compared with children of mothers aged 25-29 years (ORs ranging from 1.13 to 1.59). Compared with paternal age 25-29 years, older paternal age (40-44 years; ≥45 years) also was associated with an increased risk for CP independent of maternal age. When analyzing jointly using both parents of ages 20-34 years as the reference, the greatest risk was estimated for older parents (≥35 years). Preterm birth was estimated to mediate 19%-34% of the total effects between maternal or paternal age and offspring CP risk.

CONCLUSIONS

Young maternal age and an older age in either or both parents were associated with a greater risk of CP in their children. Although preterm birth was a mediator, additional factors related to parental age need further exploration to explain risk of CP.

Evolving Fertility Goals and Behaviors in Current U.S. Childbearing Cohorts

In the post-Recession era, U.S. fertility rates have continued to fall. It is unclear if these declines are driven by shifts in fertility goals or growing difficulty in achieving goals. In this paper, we construct synthetic cohorts of men and women to examine both cross-cohort and within-cohort changes in fertility goals using multiple cycles of the National Survey of Family Growth. Although more recent cohorts exhibit lower achieved fertility at younger ages than earlier cohorts at the same age, intended parity remains around two children, and intentions to remain childless rarely exceed 15%. There is weak evidence of a growing fertility gap in the early 30s, suggesting more recent cohorts will need considerable childbearing in the 30s and early 40s to 'catch up' to earlier goals, yet low-parity women in their early 40s are decreasingly likely to have unfulfilled fertility desires or intentions to have children. Low-parity men in their early 40s, though, are increasingly likely to intend children. Declines in U.S. fertility thus seem to be largely driven not by changes in early-life fertility goals so much as either a decreasing likelihood of achieving earlier goals or, perhaps, shifts in the preferred timing of fertility that depress period measures.

Aging affects gene expression in spermatids of Brown Norway rats

The effects of aging on the reproductive health of men and the consequences for their offspring are becoming more widely recognized. Correlative epidemiological studies examining paternal age and offspring health suggest there are more frequent occurrences of genetic disorders in the children of older fathers. Given the genetic basis for paternal age-related disorders, we aim to characterize gene expression in developing germ cells. Round spermatids (RS) were collected from young (mean = 5.3 months) and aged (mean = 19.5 months) Brown Norway rats, representative of humans aged 20-30 years and 55+ years, respectively. Gene expression data were obtained by mRNA sequencing (n = 5), and were analysed for differential expression. Sequencing data display 211 upregulated and 9 downregulated transcripts in RS of aged rats, compared to young (log2FC >1, p < 0.05). Transcripts with increased expression are involved in several processes including sperm motility/morphology, sperm-egg binding, capacitation, and epigenetic inheritance. In addition, there are numerous dysregulated transcripts that regulate germ cell epigenetic marks and Sertoli-germ cell binding and communication. These results show an overall increase in RS gene expression with age, with spermatogenic functions being perturbed. Taken together, these findings help identify the genetic origin of the fertility, germ cell niche, and epigenetic effects observed with advanced paternal aging.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Advanced Paternal Age Does Not Affect Medically-Relevant Obstetrical and Perinatal Outcomes following IVF or ICSI in Humans with Donated Oocytes

BACKGROUND

Concomitant with delays in childbearing, concerns have been raised of whether advanced paternal age is associated with adverse reproductive outcomes, but the evidence is controversial in part due to the uncertain threshold in which to consider advanced paternal age and confounding maternal factors. This retrospective study aimed to evaluate the effect of paternal age on reproductive outcomes related to the pregnancy and perinatal health of the offspring.

METHODS

We retrospectively evaluated 16,268 cases of patients who underwent IVF or ICSI (using autologous sperm and donated oocytes, between January 2008 and March 2020, at Spanish IVIRMA clinics. Patients were divided based on paternal age at conception [≤30 (n = 204), 31-40 (n = 5752), and >40 years (n = 10,312)], and the differences in obstetrical and perinatal outcomes were analyzed by descriptive analysis, followed by univariate and multivariate analysis.

RESULTS

Fathers 31-40 and >40 years old were associated with lower odds of caesarean delivery [AOR 0.63 (95% CI, 0.44-0.90; p = 0.012) and AOR 0.61 (95% CI, 0.41-0.91; p = 0.017), respectively] and longer pregnancies [ARC 5.09 (95% CI, 2.39-7.79; p < 0.001) and ARC 4.54 (95% CI, 1.51-7.58; p = 0.003), respectively] with respect to fathers ≤30 years old. Furthermore, fathers aged 31-40 years old had lower odds of having a female infant (AOR, 0.70; 95% CI, 0.49-0.99; p = 0.045) than those ≤30. The rest of obstetrical and perinatal outcomes, which we deemed more medically-relevant as they were considered serious for health, were comparable between groups with our adjusted model.

CONCLUSIONS

Despite this hopeful message to fathers of advanced paternal age, future studies should consider the short- and long-term outcomes of the offspring and try to better elucidate the associations of advanced paternal age with reproductive outcomes and the molecular mechanisms underlying the observed associations.

Associations of parental reproductive age and elevated blood pressure in offspring: An observational study

Background

Increased parental reproductive age has been a social trend around the world, and elevated blood pressure in children leads to an approximately two-fold increased risk of hypertension in adulthood. Aim of this study is to assess the associations of parental reproductive age with the risk of elevated blood pressure in offspring, and to explore the influence of offspring lifestyle on the associations.

Methods

Data was obtained from a national school program conducted in 7 Chinese provinces, and the final sample was 39,190 students aged 7-18 years. Anthropometric measurements and questionnaires were designed to collect data of children blood pressure and information respectively.

Results

In this study, 26.7% of children were defined as elevated blood pressure. A U-shaped pattern was observed in the relationship between maternal age and risk of elevated blood pressure, while risk of elevated blood pressure decreased continuously with paternal age increased. After adjustment, offspring of paternal age ≤27 & maternal age ≤26 years and those of paternal age >30 & maternal age >32 years were related to great risk of elevated blood pressure (OR = 1.18, 95% CI: 1.08-1.29, P < 0.001; OR = 1.18, 95% CI: 1.01-1.38, P < 0.05). When stratified by lifestyle status, significant associations between maternal/paternal age and risk of elevated blood pressure were only observed in those with worse lifestyle behaviors, but not in offspring with healthier lifestyle.

Conclusion

Our findings demonstrate that risk of elevated blood pressure in children is independently related to parental reproductive age, and children maintaining a healthy lifestyle may mitigate the adverse effect.