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.

Change in the perceived reproductive age window and delayed fertility in Europe

While extensive literature documents the massive fertility delay of recent decades, knowledge about whether and how attitudes towards the timing of births have changed in Europe remains limited. Using data from two rounds of the European Social Survey, we investigate these changes and their association with macro-level fertility indicators in 21 countries. Between 2006-07 and 2018-19, societal consensus regarding the existence of optimal childbearing ages remained strong and became more in favour of later parenthood. Decomposition analyses show that these shifts were driven only partially by changes in population composition, supporting the idea that a general attitudinal change in favour of later childbearing is underway. We also find a trend towards gender convergence in upper age limits driven by the increasing social recognition of an age deadline for men's childbearing. Although shifts in perceived reproductive age windows occurred during periods of birth postponement, they corresponded only loosely to country-level changes in fertility.

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.

Impact of increased paternal age on neonatal outcomes in very-low-birth-weight infants

OBJECTIVE

Despite the trend of increasing paternal age, its impact on neonatal outcomes, particularly in preterm infants, has not been thoroughly investigated. We aimed to evaluate the perinatal characteristics and neonatal outcomes associated with paternal age.

METHODS

Electronic medical records of very low-birthweight infants admitted to our unit from July 2013 to March 2022 were reviewed. Infants grouped according to paternal age (<35 years, 35-39 years, and ≥40 years) were analyzed for differences in perinatal findings and neonatal outcomes.

RESULTS

A total of 637 infants were included (194, 294, and 149 in the <35, 35-39, and ≥40 years groups, respectively). The increase in paternal age paralleled the increase in maternal age. The Z-score of head circumference at birth was significantly different between the groups, showing the lowest median value in the ≥40 years group. Small-for-gestational age (Odds ratio 71.074, p < .001, 95% confidence interval 19.337 - 261.236) and male sex (Odds ratio 3.309, p < .034, 95% confidence interval 1.089 - 8.425), but not paternal or maternal age groups were significant factors associated with head circumference Z-scores less than -2 standard deviation based on the multivariable logistic regression analysis. Infants affected by chromosomal or genetic anomaly were more frequently identified (3.4 vs 0.0 vs 0.5%) in the ≥40 years group than in the other two groups. When infants with anomalies or critical illnesses were excluded, overall neonatal outcomes did not statistically differ according to paternal age.

CONCLUSION

Although increased paternal age ≥40 years may be associated with relatively smaller head circumferences, the impact on fetal head growth does not imply a definite risk for microcephaly. Nonetheless, based on the possible negative impact on chromosomal/genetic anomaly, increased paternal age warrants attention, even though neonatal outcomes concerning prematurity were not significantly affected. A large-scale longitudinal study is needed to further elucidate the impact of advanced paternal age in preterm infants and provide guidelines for appropriate antenatal counseling and surveillance.

Paternal age and risk for selected birth defects in a large South American sample

BACKGROUND

The relationship between maternal age (MA) and birth defects (BD) has been extensively studied while much less research, mostly with discordant results, has focused on the risk of paternal age (PA) for BD. Furthermore, no consensus has been reached on the best way to control the association of PA with MA.

OBJECTIVES

The aim of the study was to evaluate the risk of PA increase, at 1-year intervals, for selected BD, especially controlling for the confounding effect of MA.

METHODS

The sample comprised of 27,944 liveborns presenting 1 of 18 selected isolated BD. Conditional logistic regressions were applied to evaluate the risk of advanced PA and its yearly increase, adjusting by MA and other variables.

RESULTS

Of the 18 analyzed BD, only the risk for preaxial polydactyly (PreP) showed a significant association with increasing PA, while advanced MA was of low risk. For esophageal and anal atresia, associations with both PA and MA increases were observed.

CONCLUSIONS

Results support the hypothesis of advanced PA as a risk factor for PreP and helps clarify the so far unexplained nonrandom association between this defect and Down syndrome.

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.

The Effect of Age on Semen Quality Among Male Partners of Infertile Couples: An Observational Study in a Tertiary Care Center in Eastern India

INTRODUCTION

Male infertility contributes to a significant proportion of infertility cases, and advanced paternal age has been suggested to affect semen quality and fertility. However, the relationship between age and semen quality remains inconclusive, with conflicting findings reported in the literature. This study aimed to investigate the effect of age on semen quality among male partners of infertile couples in a tertiary care center in eastern India.

METHODS

A cross-sectional observational study was conducted, involving 390 male participants aged 21-50 years, who were referred to the andrology laboratory for semen analysis between January 2019 and December 2022. Participants were categorized into three age groups (21-30, 31-40, and 41-50 years). Semen parameters, including sperm concentration, semen volume, motility, and morphology, were assessed according to the World Health Organization guidelines.

RESULTS

Among the participants, no significant differences were observed in semen volume, motility, and morphology across different age groups. However, a statistically significant difference in sperm concentration among the three age groups was observed (p = 0.022). Spearman correlation analysis revealed a positive correlation between age and sperm concentration (r = 0.124, p = 0.013) as well as total sperm count (r = 0.10, p = 0.049).

CONCLUSION

In this study, no significant decline in semen quality with age was found among male partners of infertile couples aged 21-50 years. These findings highlight the complex relationship between age and semen quality and emphasize the need for further research to better understand the underlying mechanisms and provide more conclusive evidence regarding the impact of age on male fertility.

Paternal Age Matters: Association with Sperm Criteria's- Spermatozoa DNA Integrity and Methylation Profile

Advanced age has been reported to negatively affect sperm parameters and spermatozoa DNA integrity. A decline in sperm criteria was also associated with altered epigenetic marks such as DNA methylation with a potential downstream impact on in vitro fertilization success and clinical outcomes. The aim of the present retrospective study was to clarify the association between advanced paternal age (APA) and sperm parameters, DNA integrity and DNA methylation profile. A total of 671 patients consulting for infertility underwent sperm analysis, sperm DNA integrity assessment and methylation level measurement. The principal finding was that individuals over 40 years of age exhibit a significant increase in DNA fragmentation levels compared to the younger group (15% versus 9%, respectively, p = 0.04). However, there was no significant difference in DNA decondensation and sperm parameters in association with APA. In addition, a drop in the global methylation level was also found in men over 40 years (6% in the young group versus 2% in the old group, p = 0.03). As a conclusion, men over 40 years are at higher risk of elevated sperm DNA fragmentation and lower methylation level. Based on these observations, it is recommended that the assessment of sperm DNA fragmentation should be taken into consideration particularly after the age of 40. Our findings support the idea that paternal age is a crucial factor that should not be neglected during fertility evaluation and treatment since it is associated with epigenetics changes in sperm. Although the underlying mechanism remains to be clarified, we believe that environmental and professional exposure factors are likely involved in the process.

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.

Sex-specific paternal age effects on offspring quality in Drosophila melanogaster

Advanced paternal age has been repeatedly shown to modulate offspring quality via male- and/or female-driven processes, and there are theoretical reasons to expect that some of these effects can be sex-specific. For example, sex allocation theory predicts that, when mated with low-condition males, mothers should invest more in their daughters compared to their sons. This is because male fitness is generally more condition-dependent and more variable than female fitness, which makes it less risky to invest in female offspring. Here, we explore whether paternal age can affect the quality and quantity of offspring in a sex-specific way using Drosophila melanogaster as a model organism. In order to understand the contribution of male-driven processes on paternal age effects, we also measured the seminal vesicle size of young and older males and explored its relationship with reproductive success and offspring quality. Older males had lower competitive reproductive success, as expected, but there was no difference between the offspring sex ratio of young and older males. However, we found that paternal age caused an increase in offspring quality (i.e., offspring weight), and that this increase was more marked in daughters than sons. We discuss different male- and female-driven processes that may explain such sex-specific paternal age effects.

Does advanced paternal age affect global DNA methylation of human spermatozoa and intracytoplasmic sperm injection outcome?

Objective

This study was performed to (I) evaluate the potential effect of advanced paternal age on global DNA methylation in spermatozoa, and (II) to investigate the association between the outcome of intracytoplasmic sperm injection (ICSI), semen parameters, and advanced paternal age.

Material and Methods

This study comprised 230 semen samples collected from males with a mean age of 38.2±8.5 years. Medical records were used to gather clinical information related to the female partner. The participants were divided into three groups depending on age: age <30 years; age 30-40 years; and age >40 years. The DNA was extracted from purified spermatozoa. Then the sperm global DNA methylation, sperm DNA fragmentation, and chromatin decondensation were evaluated by an ELISA, TUNEL, and Chromomycin A3 staining, respectively.

Results

The sample counts were n=50 (21.8%), n=90 (39.1%) and n=90 (39.1%) for the <30, 30-40 and >40 year age-groups, respectively. A significant variation was found in the age of males included in this study (p<0.001). There was a significant reduction in sperm count, total motility, and non-progressive motility in the older group compared to the younger group (p<0.001). There was also a significant elevation in chromatin decondensation, DNA fragmentation, and global DNA methylation of spermatozoa in the older age group (p<0.001). Finally, there was a significant positive correlation between the percentage of non-motile sperm, sperm chromatin decondensation, DNA fragmentation, global DNA methylation status, and paternal age (p<0.001).

Conclusion

These results suggest that advanced paternal age increased the DNA fragmentation, chromatin decondensation, and global DNA methylation level in human spermatozoa, which negatively affects the ICSI outcomes in couples undergoing ICSI cycles.

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.

Effect of advanced paternal age on reproductive outcomes in IVF cycles of non-male-factor infertility: a retrospective cohort study

Advanced paternal age has been overlooked, and its effect on fertility remains controversial. Previous studies have focused mainly on intracytoplasmic sperm injection (ICSI) cycles in men with oligozoospermia. However, few studies have reported on men with semen parameters within reference ranges. Therefore, we conducted a retrospective cohort study analyzing the reproductive outcomes of couples with non-male-factor infertility undergoing in vitro fertilization (IVF) cycles. In total, 381 cycles included were subgrouped according to paternal age (<35-year-old, 35-39-year-old, or ≥40-year-old), and maternal age was limited to under 35 years. Data on embryo quality and clinical outcomes were analyzed. The results showed that fertilization and high-quality embryo rates were not significantly different (all P > 0.05). The pregnancy rate was not significantly different in the 35-39-year-old group (42.0%; P > 0.05), but was significantly lower in the ≥40-year-old group (26.1%; P < 0.05) than that in the <35-year-old group (40.3%). Similarly, the implantation rate significantly decreased in the ≥40-year-old group (18.8%) compared with that in the <35-year-old group (31.1%) and 35-39-year-old group (30.0%) (both P < 0.05). The live birth rate (30.6%, 21.7%, and 19.6%) was not significantly different across the paternal age subgroups (<35-year-old, 35-39-year-old, and ≥40-year-old, respectively; all P > 0.05), but showed a declining trend. The miscarriage rate significantly increased in the 35-39-year-old group (44.8%) compared with that in the <35-year-old group (21.0%; P < 0.05). No abnormality in newborn birth weight was found. The results indicated that paternal age over 40 years is a key risk factor that influences the assisted reproductive technology success rate even with good semen parameters, although it has no impact on embryo development.

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

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

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.

Bio-demographic characteristics of households and risk factors for Down Syndrome in Morocco

Background

The most studied risk factors for Down Syndrom (DS) were: region of residence, exposure to chemicals, parents' education level, cigarette and alcohol use by father or mother or both, and oral contraceptive (OC) use.

Objective

The aim of this study was to compare certain variables considered as risk factors on DS such as parental age at birth, OC use, child's sex, and rank of birth between children with DS and their siblings without DS as well as to determine the socio-bio-demographic characteristics of the families studied compared with the general Moroccan population.

Material and Methods

We conducted a cross-sectional analysis of 277 families with 925 siblings and at least one child with DS (279 with DS) between 2014 and 2017. The data are collected using a standardized questionnaire in MarrakechSafi region. Data were entered and analyzed using the statistical program SPSS statistics software for Windows (version 20.0). Chi-square (χ2) and Student t tests were used for testing statistical significance. Differences were considered significant when the p-value <0.05.

Results

The binary logistic regression analysis between DS and non-DS children in their bio-demographic characteristics studied (sex, maternal age at birth, paternal age at birth, oral contraceptive (OC) use, length of oral contraceptive use before pregnancy and rank of birth) showed that only maternal age and paternal age at birth and OC use were associated with DS birth (OR= 1.16; 95% CL: 1.11-1.21, OR= 1.05; 95%CL: 1.01-1.09 and OR= 0.01; 95%CL: 0.00-0.003, respectively). In the other hand, the comparison between socio and bio-demographic characteristics of households studied with data from National Population Survey and Family health (2018) showed a higher level of education in women and men in our sample. Similar results were shown in rate of men and women in paid employment, the rate of smoking and alcohol consumption among men and the rate of OC use before pregnancy among women.

Conclusion

These results will help to sensitize the Moroccan population about risk factors for DS.

Fertility in the aging male: a systematic review

The negative effect of advanced female age on fertility and offspring health is well understood. In comparison, much less is known about the implications of male age on fertility, with many studies showing conflicting results. Nevertheless, increasing evidence suggests that advanced paternal age has negative effects on sperm parameters, reproductive success, and offspring health. Herein, we summarize the current body of knowledge on this controversial topic, with the belief that this review will serve as a resource for the clinicians providing fertility counseling to couples with older male partners.

Advanced parental age is an independent risk factor for term low birth weight and macrosomia

We aimed to investigate association between parental age and the risks of term low birth weight and macrosomia. This was a retrospective cohort study using a national database including 2,245,785 term singleton live births with complete parental age data. Old parental age was defined as 35 years or older. Odd ratios (OR) for term low birth weight and macrosomia were analyzed using univariate and multivariate logistic regression analysis. Neonatal sex, maternal occupation, parity, nationality, age, and paternal age were significant factors of term low birth weight and macrosomia, in univariate analysis. In multivariate analysis, old maternal age (≥35 years old) showed increased odds of term low birth weight and macrosomia (aOR = 1.122, 95% CI: 1.083 -1.162; and aOR = 1.166, 95% CI: 1.143 - 1.189, respectively). Similarly, old paternal age (≥35 years old) showed increased odds of term low birth weight and macrosomia (aOR = 1.090, 95% CI: 1.058 -1.122; and aOR = 1.101, 95% CI: 1.083 - 1.119, respectively). Maternal education that lasted more than 12 years had reduced odds of term low birth weight and macrosomia (OR = 0.817, 95% CI: 0.792 -0.842; and OR = 0.894, 95% CI: 0.879 - 0.91, respectively). Paternal education that lasted more than 12 years also had reduced odds of term low birth weight and macrosomia (OR = 0.865, 95% CI: 0.84 -0.892; and OR = 0.897, 95% CI: 0.881 - 0.913, respectively). This study suggests that not only maternal age but also paternal age are significantly associated with term low birth weight and macrosomia. In addition, parental education levels are also associated with term low birth weight and macrosomia.

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.

De novo mutations in children born after medical assisted reproduction

STUDY QUESTION

Are there more de novo mutations (DNMs) present in the genomes of children born through medical assisted reproduction (MAR) compared to spontaneously conceived children?

SUMMARY ANSWER

In this pilot study, no statistically significant difference was observed in the number of DNMs observed in the genomes of MAR children versus spontaneously conceived children.

WHAT IS KNOWN ALREADY

DNMs are known to play a major role in sporadic disorders with reduced fitness such as severe developmental disorders, including intellectual disability and epilepsy. Advanced paternal age is known to place offspring at increased disease risk, amongst others by increasing the number of DNMs in their genome. There are very few studies reporting on the effect of MAR on the number of DNMs in the offspring, especially when male infertility is known to be affecting the potential fathers. With delayed parenthood an ongoing epidemiological trend in the 21st century, there are more children born from fathers of advanced age and more children born through MAR every day.

STUDY DESIGN, SIZE, DURATION

This observational pilot study was conducted from January 2015 to March 2019 in the tertiary care centre at Radboud University Medical Center. We included a total of 53 children and their respective parents, forming 49 trios (mother, father and child) and two quartets (mother, father and two siblings). One group of children was born after spontaneous conception (n = 18); a second group of children born after IVF (n = 17) and a third group of children born after ICSI combined with testicular sperm extraction (ICSI-TESE) (n = 18). In this pilot study, we also subdivided each group by paternal age, resulting in a subgroup of children born to younger fathers (<35 years of age at conception) and older fathers (>45 years of age at conception).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Whole-genome sequencing (WGS) was performed on all parent-offspring trios to identify DNMs. For 34 of 53 trios/quartets, WGS was performed twice to independently detect and validate the presence of DNMs. Quality of WGS-based DNM calling was independently assessed by targeted Sanger sequencing.

MAIN RESULTS AND THE ROLE OF CHANCE

No significant differences were observed in the number of DNMs per child for the different methods of conception, independent of parental age at conception (multi-factorial ANOVA, f(2) = 0.17, P-value = 0.85). As expected, a clear paternal age effect was observed after adjusting for method of conception and maternal age at conception (multiple regression model, t = 5.636, P-value = 8.97 × 10-7), with on average 71 DNMs in the genomes of children born to young fathers (<35 years of age) and an average of 94 DNMs in the genomes of children born to older fathers (>45 years of age).

LIMITATIONS, REASONS FOR CAUTION

This is a pilot study and other small-scale studies have recently reported contrasting results. Larger unbiased studies are required to confirm or falsify these results.

WIDER IMPLICATIONS OF THE FINDINGS

This pilot study did not show an effect for the method of conception on the number of DNMs per genome in offspring. Given the role that DNMs play in disease risk, this negative result is good news for IVF and ICSI-TESE born children, if replicated in a larger cohort.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by the Netherlands Organisation for Scientific Research (918-15-667) and by an Investigator Award in Science from the Wellcome Trust (209451). The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

[Analysis of risk factors for the development of infertility in men from infertile couples, depending on age.]

According to the Russian Society of Urologists, the frequency of infertility in marriage in the Russian Federation is 8-17,2%; half of the cases are associated with the male factor. Among the risk factors for the development of male infertility, there are mainly medical reasons, lifestyle factors and negative environmental factors. Despite the fact that the problem of infertility is addressed by men of different ages, from youth to the elderly, the correction of risk factors is usually carried out without taking into account the age of the patient, which makes it difficult to develop a personalized strategy for the treatment or prevention of infertility. The aim of the study was to study the structure of the leading risk factors for the development of infertility in men from infertile couples, to identify and characterize their age-associated features. The analysis of the medical histories of 1 198 men from infertile couples and the collection of information on all available risk factors for infertility were carried out. The analysis of age features was performed by dividing the sample into 5 age groups: 1st (n=271) - men ≤29,9 years; 2nd (n=415) - 30-34,9 years; 3rd (n=291) - 35-39,9 years; 4th (n=141) - 40-44,9 years; 5th (n=80) - ≥45 years. It was shown that in the general sample of medical causes, factors associated with chronic inflammation predominate: sexually transmitted infections (STIs) - 54%; prostatitis - 32%; obesity - 27%; from non-medical: alcohol - 73%; stress - 47%; smoking - 41%. With increasing age, the frequency of obesity, STIs, prostatitis, hepatitis B/C, mumps increases statistically significantly, while the most unfavorable group of men is 40-45 years old for factors such as STIs, hepatitis B/C and mumps, and the group of men over 45 years old for factors such as obesity and prostatitis.

Development of thalamus mediates paternal age effect on offspring reading: A preliminary investigation

The importance of (inherited) genetic impact in reading development is well established. De novo mutation is another important contributor that is recently gathering interest as a major liability of neurodevelopmental disorders, but has been neglected in reading research to date. Paternal age at childbirth (PatAGE) is known as the most prominent risk factor for de novo mutation, which has been repeatedly shown by molecular genetic studies. As one of the first efforts, we performed a preliminary investigation of the relationship between PatAGE, offspring's reading, and brain structure in a longitudinal neuroimaging study following 51 children from kindergarten through third grade. The results showed that greater PatAGE was significantly associated with worse reading, explaining an additional 9.5% of the variance after controlling for a number of confounds-including familial factors and cognitive-linguistic reading precursors. Moreover, this effect was mediated by volumetric maturation of the left posterior thalamus from ages 5 to 8. Complementary analyses indicated the PatAGE-related thalamic region was most likely located in the pulvinar nuclei and related to the dorsal attention network by using brain atlases, public datasets, and offspring's diffusion imaging data. Altogether, these findings provide novel insights into neurocognitive mechanisms underlying the PatAGE effect on reading acquisition during its earliest phase and suggest promising areas of future research.

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

Objective

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

Subjects and Methods

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

Results

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

Conclusions

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

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVE

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

DESIGN

Retrospective cohort.

SETTING

Not applicable.

PATIENT(S)

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

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

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

RESULT(S)

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

CONCLUSION(S)

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

From late fatherhood to prenatal screening of monogenic disorders: evidence and ethical concerns

BACKGROUND

With the help of ART, an advanced parental age is not considered to be a serious obstacle for reproduction anymore. However, significant health risks for future offspring hide behind the success of reproductive medicine for the treatment of reduced fertility associated with late parenthood. Although an advanced maternal age is a well-known risk factor for poor reproductive outcomes, understanding the impact of an advanced paternal age on offspring is yet to be elucidated. De novo monogenic disorders (MDs) are highly associated with late fatherhood. MDs are one of the major sources of paediatric morbidity and mortality, causing significant socioeconomic and psychological burdens to society. Although individually rare, the combined prevalence of these disorders is as high as that of chromosomal aneuploidies, indicating the increasing need for prenatal screening. With the help of advanced reproductive technologies, families with late paternity have the option of non-invasive prenatal testing (NIPT) for multiple MDs (MD-NIPT), which has a sensitivity and specificity of almost 100%.

OBJECTIVE AND RATIONALE

The main aims of the current review were to examine the effect of late paternity on the origin and nature of MDs, to highlight the role of NIPT for the detection of a variety of paternal age-associated MDs, to describe clinical experiences and to reflect on the ethical concerns surrounding the topic of late paternity and MD-NIPT.

SEARCH METHODS

An extensive search of peer-reviewed publications (1980-2021) in English from the PubMed and Google Scholar databases was based on key words in different combinations: late paternity, paternal age, spermatogenesis, selfish spermatogonial selection, paternal age effect, de novo mutations (DNMs), MDs, NIPT, ethics of late fatherhood, prenatal testing and paternal rights.

OUTCOMES

An advanced paternal age provokes the accumulation of DNMs, which arise in continuously dividing germline cells. A subset of DNMs, owing to their effect on the rat sarcoma virus protein-mitogen-activated protein kinase signalling pathway, becomes beneficial for spermatogonia, causing selfish spermatogonial selection and outgrowth, and in some rare cases may lead to spermatocytic seminoma later in life. In the offspring, these selfish DNMs cause paternal age effect (PAE) disorders with a severe and even life-threatening phenotype. The increasing tendency for late paternity and the subsequent high risk of PAE disorders indicate an increased need for a safe and reliable detection procedure, such as MD-NIPT. The MD-NIPT approach has the capacity to provide safe screening for pregnancies at risk of PAE disorders and MDs, which constitute up to 20% of all pregnancies. The primary risks include pregnancies with a paternal age over 40 years, a previous history of an affected pregnancy/child, and/or congenital anomalies detected by routine ultrasonography. The implementation of NIPT-based screening would support the early diagnosis and management needed in cases of affected pregnancy. However, the benefits of MD-NIPT need to be balanced with the ethical challenges associated with the introduction of such an approach into routine clinical practice, namely concerns regarding reproductive autonomy, informed consent, potential disability discrimination, paternal rights and PAE-associated issues, equity and justice in accessing services, and counselling.

WIDER IMPLICATIONS

Considering the increasing parental age and risks of MDs, combined NIPT for chromosomal aneuploidies and microdeletion syndromes as well as tests for MDs might become a part of routine pregnancy management in the near future. Moreover, the ethical challenges associated with the introduction of MD-NIPT into routine clinical practice need to be carefully evaluated. Furthermore, more focus and attention should be directed towards the ethics of late paternity, paternal rights and paternal genetic guilt associated with pregnancies affected with PAE MDs.

Are paternal or grandmaternal age associated with higher probability of trisomy 21 in offspring? A population-based, matched case-control study, 1995-2015

BACKGROUND

Fetal aneuploidy risk increases with maternal age, but the majority of pregnancies complicated by trisomy 21 occur in younger women. It has been suggested that grandmaternal and/or paternal age may also play a role.

OBJECTIVES

To assess the association between grandmaternal and paternal age and trisomy 21.

METHODS

For the grandmaternal assessments, we included all offspring with trisomy 21 in a statewide birth defects surveillance system (1995-2015) that could be linked to 3-generation matrilineal pedigrees in the Utah Population Database. Ten sex/birth year-matched controls were selected for each case (770 cases and 7700 controls). For the paternal assessments, our cohort included all trisomy 21 cases (1995-2015) where both the mother and father resided in Utah at the time of birth (1409 cases and 14 090 controls). Ages were categorised by 5-year intervals (reference: 25-29 years). Conditional logistic regression, adjusting for potential confounding factors, was used to model the association between grandmaternal and paternal age and trisomy 21.

RESULTS

No association between grandmaternal age and trisomy 21 was detected, whether age was assessed continuously (adjusted odds ratio [OR] 1.01, 95% confidence interval [CI] 0.98, 1.03) or categorically after adjusting for grandmaternal and grandpaternal race/ethnicity and grandpaternal age. Compared to fathers aged 20-29 years, fathers <20 years (OR 3.15, 95% CI 1.99, 4.98) and 20-24 years (OR 1.39, 95% CI 1.11, 1.73) had increased odds of trisomy 21 offspring, after adjusting for maternal and paternal race/ethnicity and maternal age. Results were consistent after excluding stillbirths, multiples, and trisomy 21 due to translocation or mosaicism.

CONCLUSIONS

Maternal age is an important risk factor for trisomy 21 offspring; however, this population-based study shows that that young paternal age is also associated with trisomy 21, after taking into account maternal age and race/ethnicity.

Association between advanced paternal age and congenital heart defects: a systematic review and meta-analysis

STUDY QUESTION

Is there an association between advanced paternal age and congenital heart defects (CHD)?

SUMMARY ANSWER

Advanced paternal age is associated with a 16% increase in the overall odds of CHD.

WHAT IS KNOWN ALREADY

CHD are the most common congenital malformations. Several risk factors for CHD have been identified in the literature, but the association between advanced paternal age and CHD remains unclear.

STUDY DESIGN, SIZE, DURATION

We conducted a systematic literature search on MEDLINE and EMBASE (1960-2019) to identify studies assessing the association between advanced paternal age (≥35 years) and the risk of CHD, unrestrictive of language or sample size. We used a combination of Medical Subject Headings (MeSH) terms and free text words such as 'paternal age', 'paternal factors', 'father's age', 'parental age', 'heart', 'cardiac', 'cardiovascular', 'abnormalities, congenital', 'birth defects', 'congenital malformations' and 'congenital abnormalities'.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We included observational studies aiming at assessing the association between paternal age and CHD. The included population could be live births, fetal deaths and terminations of pregnancy for fetal anomaly. To be included, studies had to provide either odds ratios (OR) with their 95% confidence interval (CI) or sufficient information to recalculate ORs with 95% CIs per paternal age category. We excluded studies if they had no comparative group and if they were reviews or case reports. Two independent reviewers selected the studies, extracted the data and assessed risk of bias using a modified Newcastle-Ottawa Scale. We used random-effects meta-analysis to produce summary estimates of crude OR. Associations were also tested in subgroups.

MAIN RESULTS AND THE ROLE OF CHANCE

Of 191 studies identified, we included nine studies in the meta-analysis (9 917 011 participants, including 34 447 CHD), including four population-based studies. Five studies were judged at low risk of bias. Only one population-based study specifically investigated isolated CHD. The risk of CHD was higher with advanced paternal age (summary OR 1.16, 95% CI, 1.07-1.25). Effect sizes were stable in population-based studies and in those with low risk of bias.

LIMITATIONS AND REASONS FOR CAUTION

The available evidence did not allow to assess (i) the risk of isolated CHD in population-based studies, (ii) the association between paternal age and the risk for specific CHD and (iii) the association between paternal age and CHD after adjustment for other risk factors, such as maternal age.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that advanced paternal age may be a risk factor for CHD. However, because the association is modest in magnitude, its usefulness as a criterion for targeted screening for CHD seems limited.

STUDY FUNDING/COMPETING INTEREST(S)

None.

PROSPERO REGISTRATION NUMBER

CRD42019135061.

Paternal age negatively affects sperm production of the progeny

Parental age has profound consequences for offspring's phenotype. However, whether patrilineal age affects offspring sperm production remains unknown, despite the importance of sperm production for male reproductive success in species facing post-copulatory sexual selection. Using a longitudinal dataset on ejaculate attributes of the houbara bustard, we showed that offspring sired by old fathers had different age-dependent trajectories of sperm production compared to offspring sired by young fathers. Specifically, they produced less sperm (-48%) in their first year of life, and 14% less during their lifetime. Paternal age had the strongest effect, with weak evidence for grandpaternal or great grandpaternal age effects. These results show that paternal age can affect offspring reproductive success by reducing sperm production, establishing an intergenerational link between ageing and sexual selection.

Effects of Gender of Reciprocal Chromosomal Translocation on Blastocyst Formation and Pregnancy Outcome in Preimplantation Genetic Testing

OBJECTIVE

To determine the effect of gender of reciprocal chromosomal translocation on blastocyst formation and pregnancy outcome in preimplantation genetic testing, including different parental ages.

METHODS

This was a retrospective cohort study that enrolled 1034 couples undergoing preimplantation genetic testing-structural rearrangement on account of a carrier of reciprocal chromosomal translocation from the Reproductive Medicine Center of the First Affiliated Hospital of Zhengzhou University from January 2015 to December 2019. Group A represented 528 couples in which the man was the carrier of reciprocal translocation and group B represented 506 couples in which the woman was the carrier of reciprocal translocation. All patients were divided into two groups according to their age: female age<35 and female age≥35. Furthermore, the differences in blastocyst condition and pregnancy outcome between male and female carriers in each group were further explored according to their father's age.

RESULTS

The blastocyst formation rate of group A (55.3%) is higher than that of group B (50%) and the results were statistically significant (P<0.05). The blastocyst formation rate of group A is higher than that of group B, no matter in young maternal age or in advanced maternal age (P<0.05). The blastocyst formation rate in maternal age<35y and paternal age<30y in group A(57.1%) is higher than that of Group B(50%); Similarly, the blastocyst formation rate in maternal age≥35 and paternal age≥38y(66.7%) is higher than that of Group B(33.3%)(all P<0.05). There was no difference in fertilization rate, aeuploidy rate, clinical pregnancy rate, miscarriage rate and live birth rate between Group A and Group B.

CONCLUSION

When the carrier of reciprocal translocation is male, the blastocyst formation rate is higher than that of female carrier. While there is no significant difference between the two in terms of fertilization rate, aeuploidy rate, clinical pregnancy rate, miscarriage rate and live birth rate.

Corrigendum: Effects of Gender of Reciprocal Chromosomal Translocation on Blastocyst Formation and Pregnancy Outcome in Preimplantation Genetic Testing

[This corrects the article DOI: 10.3389/fendo.2021.704299.].

Is there an association between paternal age and aneuploidy? Evidence from young donor oocyte-derived embryos: a systematic review and individual patient data meta-analysis

BACKGROUND

Delayed parenthood, by both women and men, has become more common in developed countries. The adverse effect of advanced maternal age on embryo aneuploidy and reproductive outcomes is well known. However, whether there is an association between paternal age (PA) and embryonic chromosomal aberrations remains controversial. Oocyte donation (OD) is often utilized to minimize maternal age effects on oocyte and embryo aneuploidy, thus providing an optimal model to assess the effect of PA. Several studies have revealed a higher than expected rate of aneuploidy in embryos derived from young oocyte donors, which warrants examination as to whether this may be attributed to advanced PA (APA).

OBJECTIVE AND RATIONALE

The objective of this systematic review and individual patient data (IPD) meta-analysis is to evaluate existing evidence regarding an association between PA and chromosomal aberrations in an OD model.

SEARCH METHODS

This review was conducted according to PRISMA guidelines for systematic reviews and meta-analyses. Medline, Embase and Cochrane databases were searched from inception through March 2020 using the (MeSH) terms: chromosome aberrations, preimplantation genetic screening and IVF. Original research articles, reporting on the types and/or frequency of chromosomal aberrations in embryos derived from donor oocytes, including data regarding PA, were included. Studies reporting results of IVF cycles using only autologous oocytes were excluded. Quality appraisal of included studies was conducted independently by two reviewers using a modified Newcastle-Ottawa Assessment Scale. A one-stage IPD meta-analysis was performed to evaluate whether an association exists between PA and aneuploidy. Meta-analysis was performed using a generalized linear mixed model to account for clustering of embryos within patients and clustering of patients within studies.

OUTCOMES

The search identified 13 032 references, independently screened by 2 reviewers, yielding 6 studies encompassing a total of 2637 IVF-OD cycles (n = 20 024 embryos). Two 'low' quality studies using FISH to screen 12 chromosomes on Day 3 embryos (n = 649) reported higher total aneuploidy rates and specifically higher rates of trisomy 21, 18 and 13 in men ≥50 years. One 'moderate' and three 'high' quality studies, which used 24-chromosome screening, found no association between PA and aneuploidy in Day 5/6 embryos (n = 12 559). The IPD meta-analysis, which included three 'high' quality studies (n = 10 830 Day 5/6 embryos), found no significant effect of PA on the rate of aneuploidy (odds ratio (OR) 0.97 per decade of age, 95% CI 0.91-1.03), which was robust to sensitivity analyses. There was no association between PA and individual chromosome aneuploidy or segmental aberrations, including for chromosomes X and Y (OR 1.06 per decade of age, 95% CI 0.92-1.21). Monosomy was most frequent for chromosome 16 (217/10802, 2.01%, 95% CI 1.76-2.29%) and trisomy was also most frequent for chromosome 16 (194/10802, 1.80%, 95% CI 1.56-2.06%).

WIDER IMPLICATIONS

We conclude, based on the available evidence, that APA is not associated with higher rates of aneuploidy in embryos derived from OD. These results will help fertility practitioners when providing preconception counselling, particularly to older men who desire to have a child.

Advanced paternal age and risk of cancer in offspring

Many risk factors of cancer have been established, but the contribution of paternal age in this regard remains largely unexplored. To further understand the etiology of cancer, we investigated the relationship between paternal age and cancer incidence using PLCO cohort. Cox proportional hazards models were performed to assess the association between paternal age and the risk of cancers. During follow-up time (median 11.5 years), 18,753 primary cancers occurred. Paternal age was associated with reduced risk of cancers of the female genitalia (HR, 0.79; 95%CI, 0.66-0.94; P = 0.008) as well as cancers of the respiratory and intrathoracic organs (HR, 0.78; 95%CI, 0.63-0.97; P = 0.026). The association was stronger for lung cancer (HR, 0.67; 95%CI, 0.52-0.86; P = 0.002). The subgroup analysis suggested that age, gender, smoking and BMI were related to the decreased cancer incidence of the respiratory and intrathoracic organs, lung and the female genitalia. Positive linear associations were observed between paternal age and cancer incidence of the female genitalia, respiratory and intrathoracic organs and the lungs. These findings indicate that advanced paternal age is an independent protective factor against various cancers in offspring.

Effect of paternal age on offspring birth defects: a systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis was aimed at determining whether paternal age is a risk factor for offspring birth defects.

RESULTS

A total of 38 and 11 studies were included in the systematic review and meta-analysis, respectively. Compared with reference, fathers aged 25 to 29, young fathers (< 20 years) could increase the risk of urogenital abnormalities (OR: 1.50, 95 % CI: 1.03-2.19) and chromosome disorders (OR: 1.38, 95 % CI: 1.12-1.52) in their offsprings; old fathers (≥ 40 years) could increase the risk of cardiovascular abnormalities (OR: 1.10, 95 % CI: 1.01-1.20), facial deformities (OR: 1.08, 95 % CI: 1.00-1.17), urogenital abnormalities (OR: 1.28, 95 % CI: 1.07-1.52), and chromosome disorders (OR: 1.30, 95 % CI: 1.12-1.52).

CONCLUSIONS

Our study indicated that paternal age is associated with a moderate increase in the incidence of urogenital and cardiovascular abnormalities, facial deformities, and chromosome disorders.

METHODS

PubMed, Web of Science, the Cochrane Library, and Embase were searched for relevant literatures from 1960 to February 2020. The systematic review follows PRISMA guidelines. Relevant meta-analyses were performed.

The other face of advanced paternal age: a scoping review of its terminological, social, public health, psychological, ethical and regulatory aspects

BACKGROUND

There is a global tendency for parents to conceive children later in life. The maternal dimension of the postponement transition has been thoroughly studied, but interest in the paternal side is more recent. For the moment, most literature reviews on the topic have focused on the consequences of advanced paternal age (APA) on fertility, pregnancy and the health of the child.

OBJECTIVE AND RATIONALE

The present review seeks to move the focus away from the biological and medical dimensions of APA and synthesise the knowledge of the other face of APA.

SEARCH METHODS

We used the scoping review methodology. Searches of interdisciplinary articles databases were performed with keywords pertaining to APA and its dimensions outside of biology and medicine. We included scientific articles, original research, essays, commentaries and editorials in the sample. The final sample of 177 documents was analysed with qualitative thematic analysis.

OUTCOMES

We identified six themes highlighting the interdisciplinary nature of APA research. The 'terminological aspects' highlight the lack of consensus on the definition of APA and the strategies developed to offer alternatives. The 'social aspects' focus on the postponement transition towards reproducing later in life and its cultural dimensions. The 'public health aspects' refer to attempts to analyse APA as a problem with wider health and economic implications. The 'psychological aspects' focus on the consequences of APA and older fatherhood on psychological characteristics of the child. The 'ethical aspects' reflect on issues of APA emerging at the intersection of parental autonomy, children's welfare and social responsibility. The 'regulatory aspects' group different suggestions to collectively approach the implications of APA. Our results show that the field of APA is still in the making and that evidence is lacking to fully address the issues of APA. The review suggests promising avenues of research such as introducing the voice of fathers of advanced age into the research agenda.

WIDER IMPLICATIONS

The results of this review will be useful for developing policies and preconception health interventions that consider and include prospective fathers of advanced age.

Association between paternal age and offspring's under-5 mortality: Data from 159 surveys in 67 low- to middle-income countries

AIM

To investigat the association between paternal age at birth and offspring's under-5 mortality in low- and middle-income countries (LIMCs).

METHODS

Data from 159 population-based surveys in 67 LIMCs between 2000 and 2018 were obtained from the Demographic and Health Surveys. Cox proportional hazard regression models in consideration of complex survey design were performed to examine the associations.

RESULTS

In the pooled analysis, compared with children born to fathers aged 25-29 years, those born to younger fathers aged 20-24, 16-19 and 12-15 years, respectively, were at increased risk of under-5 mortality (hazard ratio (HR) = 1.09, 95% confidence interval (CI) = 1.06-1.13; HR = 1.48, 95% CI = 1.42-1.55; HR = 1.70, 95% CI = 1.56-1.84, respectively). In addition, children born to older fathers aged 40-44 and ≥ 45 years, also had increased risk of under-5 mortality (HR = 1.08, 95% CI = 1.03-1.15; HR = 1.12, 95% CI = 1.07-1.18, respectively).

CONCLUSIONS

Our findings show that children born to both younger and older fathers are at higher risk of offspring's under-5 mortality in LIMCs.

Psychotic Experiences Are Associated With Paternal Age But Not With Delayed Fatherhood in a Large, Multinational, Community Sample

Advanced paternal age has been consistently associated with an increased risk of schizophrenia. It is less known if such an association also exists with subclinical/attenuated forms of psychosis. Additionally, it has been suggested that it is not paternal age per se, but rather delayed fatherhood, as a marker of a genetic liability of psychosis, that is the cause of the association. The aim of the current study was to examine whether paternal age and/or delayed fatherhood (paternity age) predict self-reported positive, negative, and/or depressive dimensions of psychosis in a large sample from the general population. The sample (N = 1465) was composed of control subjects from the 6 countries participating in the European Union Gene-Environment Interaction study. The CAPE, a self-report questionnaire, was used to measure dimensions of subclinical psychosis. Paternal age at the time of respondents' birth and age of paternity were assessed by self-report. We assessed the influence of the variables of interest (paternal age or paternity age) on CAPE scores after adjusting for potential confounders (age, gender, and ethnicity). Paternal age was positively associated with the positive dimension of the CAPE. By contrast, paternity age was not associated with any of the psychosis dimensions assessed by the CAPE. Thus, our results do not support the idea that delayed fatherhood explains the association between age of paternity and psychosis risk. Furthermore, our results provide arguments for the hypothesis of an etiologic continuum of psychosis.

Parental Age and the Risk of Cleft Lip and Palate in a Nigerian Population - A Case-Control Study

Introduction:

Orofacial clefts are one of the most common congenital malformations in the facial region. Older maternal or paternal age presents higher odds of a child with an orofacial cleft. The objective of the study was to assess the association between parental age and risk of orofacial cleft.

Materials and Methods:

This was a case–control study among 110 parents of children with orofacial cleft (case group) and 110 parents of children without orofacial cleft (control group). Information on maternal age, paternal age, and type of orofacial cleft in the children were obtained. The results were analyzed using descriptive statistics, Chi-square analysis, and bivariate logistic regressions to measure the association between parental age and orofacial cleft. The value of P was <0.05, with a 95% confidence interval (CI).

Results:

Information on 219 children (109 cases and 110 controls) was analyzed, of which 52% were females. One respondent from the case group withdrew from the study. The odds of a child with orofacial cleft was statistically significantly lower in mothers aged 26–35 years compared to mothers aged 25 years and less (odds ratio [OR]: 0.32; 95% CI: 0.16, 0.79). Similarly, fathers aged above 35 years had statistically significantly lower odds of children with orofacial cleft than those 25 years and less (OR: 0.18; 95% CI: 0.02, 0.99).

Discussion:

Our findings suggest that mothers aged 26-35 years may have lower odds of giving birth to babies with orofacial clefts, compared to younger mothers. Similarly, fathers aged above 35 years may have lower odds of giving birth to a child with orofacial cleft compared to fathers aged 25 years and less.

Is there a correlation between paternal age and aneuploidy rate? An analysis of 3,118 embryos derived from young egg donors

OBJECTIVE

To investigate a possible correlation between chromosomal aberrations and paternal age, analyzing embryos derived from young oocyte donors, with available preimplantation genetic testing for aneuploidy results from day 5/6 trophectoderm biopsy obtained by next-generation sequencing for all 24 chromosomes.

DESIGN

Retrospective cohort study.

SETTING

Canadian fertility centre.

PATIENT(S)

A total of 3,118 embryos from 407 male patients, allocated into three paternal age groups: group A, ≤39 years (n = 203); group B, 40-49 years (n = 161); group C, ≥50 years (n = 43).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The primary outcomes were aneuploidy, euploidy, mosaicism, and blastocyst formation rates. Secondary endpoints were comparison of specific chromosome aneuploidy, segmental and complex (involving two chromosomes + mosaicism >50%) aneuploidy, and analysis of overall percentage of chromosomal gains and losses within each group.

RESULT(S)

The study included 437 in vitro fertilization (IVF) antagonist cycles using 302 oocyte donors in which preimplantation genetic testing for aneuploidy was performed. Overall, 70.04% of embryos were euploid, 13.9% were aneuploid, and 16.06% were mosaic. No significant differences among paternal age groups A, B, and C were found in euploidy rates (69.2%, 70.6%, 71.4%, respectively), aneuploidy rates (14.7%, 12.8%, 13.9%, respectively) or mosaicism rates (16.1%, 16.6%, 13.6%; respectively). The fertilization rate was lower in group C compared with group B (76.35% vs. 80.09%). No difference was found in blastocyst formation rate between the study groups (median 52% [interquartile range, 41%, 67%] vs. 53% [42%, 65%] vs. 52% [42%, 64%], respectively). A generalized linear mixed model regression analysis for embryo ploidy rates found older oocyte donor age to be independently associated with embryo aneuploidy (odds ratio = 1.041; 95% CI, 1.009-1.074). The rate of segmental aneuploidies was significantly higher in the older versus younger paternal age group (36.6% vs. 19.4%).

CONCLUSION(S)

No association was found between paternal age and aneuploidy rates in embryos derived from IVF cycles using young oocyte donors, after adjusting for donor, sperm, and IVF cycle characteristics. Advanced paternal age ≥ 50, compared with younger paternal ages, was associated with a lower fertilization rate and increased rate of segmental aberrations.

Paternal age, body mass index, and semen volume are associated with chromosomal aberrations-related miscarriages in couples that underwent treatment by assisted reproductive technology

We investigated the effects of paternal characteristics, including age, body mass index (BMI), and semen parameters on chromosomal aberration-related miscarriages in couples that underwent treatment with assisted reproductive technology (ART). Single nucleotide polymorphism (SNP) array analysis showed chromosomal aberrations in 60.2% (557/925) of miscarried fetuses, including trisomy in 73.1% (407/557) of cases. There were higher chromosomal aberration rates in fetuses for men aged 20-24 years and ≥30 years compared with controls. After adjusting for age and BMI of the female partners, and the BMI and semen parameters of the males, there was no statistically significant effect of paternal age ≥30 years on the risk of chromosomal aberrations-related miscarriages. However, the odds of chromosomal abnormality-related miscarriage were 148% higher for the youngest fathers (age: 20-24 years) than fathers aged 25-29 years [adjusted odds ratio (OR): 2.48, 95% confidence interval (CI): 1.03-5.96; P=0.042]. Furthermore, high male BMI (adjusted OR: 1.56, 95% CI: 1.14-2.14; P=0.005) and low semen volume (adjusted OR: 2.09, 95% CI: 1.06-4.11; P=0.034) were associated with increased risk of chromosomal aberration-related miscarriages. These findings demonstrate that very young paternal age, high BMI, and low semen volume are associated with increased risk of chromosomal aberration-related miscarriages in couples undergoing ART treatment.

The effects of aging on semen parameters and sperm DNA fragmentation

INTRODUCTION

This study aimed to look into possible correlations between male age and different sperm parameters derived from semen analysis and sperm deoxyribonucleic acid (DNA) fragmentation.

METHODS

This retrospective descriptive study included 2681 male patients who underwent semen analysis at Clínica Las Condes (CLC), Santiago, Chile, between January 2014 and May 2017; correlations between age and sperm parameters were analyzed.

RESULTS

Males above the age of 50 were significantly more likely to present anomalies in semen volume, sperm concentration, and sperm DNA fragmentation; males aged 41+ years were more likely to have lower sperm concentration levels; males aged 31+ years were more likely to have decreased sperm motility; when concentration was constant, more volume and motility anomalies were seen as age increased; when volume was kept constant, more motility and concentration anomalies were seen as age increased; and when motility was constant, normal semen volumes decreased as age increased.

CONCLUSION

Our study showed that male age significantly affects sperm parameters that might have an impact on male fertility.

The Association between Advanced Maternal Age and Diagnosis of Small for Gestational Age

OBJECTIVES

To identify whether advanced maternal age (AMA), defined as age ≥35 years old, is independently associated with small for gestational age (SGA).

STUDY DESIGN

This was a retrospective cohort of births from the National Vital Statistics System in the United States from 2009 to 2013. Women were categorized based on four age groups at the time of delivery: 20 to 29, 30 to 34, 35 to 39, and ≥40 years old. The primary outcome of SGA < 10th and SGA < 5th percentiles was compared between the four groups using both univariable and multivariable analyses to determine whether maternal age was associated with SGA independent of parity.

RESULTS

A total of 17,031,005 births were eligible for analysis, with 2,705,501 births to AMA women. In multivariable analyses, maternal age of 30 to 34, compared with 20 to 29, was associated with lower rates of SGA < 10th and <5th percentiles (adjusted odds ratio [aOR] = 0.95; 95% confidence interval [CI]: 0.95-0.96 and aOR = 0.97; 95% CI: 0.96-0.98, respectively). The AMA of 35 to 39, compared with 20 to 29, was associated with lower rates of SGA < 10th percentile and unchanged rates of SGA < 5th percentile (aOR = 0.97; 95% CI: 0.96-0.98 and aOR = 1; 95% CI: 0.99-1.01, respectively). In contrast, AMA of ≥40, compared with age 20 to 29, was associated with higher rates of both SGA < 10th and <5th percentiles (aOR = 1.06; 95% CI: 1.04-1.07 and aOR = 1.14; 95% CI: 1.12-1.16, respectively). A significant association was found between maternal age and parity toward the risk of SGA (p < 0.001). Nulliparous women ≥30 years old but not multiparous women had higher rates of SGA < 10th and SGA < 5th percentiles compared with nulliparous women in the age group of 20 to 29. In contrast, both nulliparous and multiparous women age ≥40 years old had an increased risk for SGA < 5th percentile compared with all women in the age group of 20 to 29.

CONCLUSION

Nulliparous women aged 30 years and older have higher risk of SGA < 10th and SGA < 5th percentiles compared with nulliparous women age 20 to 29. In contrast, both nulliparous and multiparous women age 40 years and older have an increased risk of SGA < 5th percentile compared with all women in the age group of 20 to 29.

Paternal age is affected by genetic abnormalities, perinatal complications and mental health of the offspring

Infertility and fecundity problems concern 10-18% of partners in their reproductive years compromising around one million females and males in Poland. Research and analysis of factors that affect male fertility are limited, especially, regarding the age of the father and determining the age at which quality of semen decreases. Age of the father has greater impact than maternal age, on cases of sporadic autosomal dominant congenital diseases such as Apert, Crouzon, Pfeiffer, Noonan and Costello syndromes, multiple endocrine neoplasia (types 2A and 2B) and achondroplasia. However, there are only a few reports taking paternal advanced age into consideration for pre-mature birth, low Apgar scores or admission to a neonatal intensive care department. Paternal age increases the frequency of congenital diseases such as heart malformations as well as oral, palate and lip cleft. Moreover, mental disorders (autism, schizophrenia, bipolar disorder, low IQ level as well as ADHD) also occur more frequently in advanced father's age. Advanced paternal age is defined differently in every research. It depends on disorders in offspring we are talking about. Paternal age has an impact on child's health and development and it is as significant as maternal age, when it comes to reproductive matters.

Advanced paternal age and the risk of spontaneous abortion: an analysis of the combined 2011-2013 and 2013-2015 National Survey of Family Growth

BACKGROUND

Maternal and paternal age at first birth are increasing across the global population. Spontaneous abortion, one of the most common abnormal pregnancy outcomes, is known to occur more frequently with increasing maternal age. However, the relationship of advanced paternal age and spontaneous abortion is poorly understood, and previous results have yielded conflicting results.

OBJECTIVE

To examine the influence of paternal age on the risk of spontaneous abortion among singleton pregnancies conceived without assisted reproductive technologies.

MATERIALS AND METHODS

This was a retrospective, case-control study using combined pregnancy data from the Centers for Disease Control and Prevention's 2011-2013 and 2013-2015 National Survey of Family Growth. Spontaneous, singleton pregnancy data from women aged 15-45 years were analyzed. Ongoing pregnancies, induced abortions, ectopic pregnancies, preterm births, and intrauterine fetal deaths were excluded. Bivariate associations of pregnancy outcome (spontaneous abortion at <20 weeks and ≤12 weeks vs. live birth at ≥37 weeks) and paternal age were determined, along with those of maternal age and selected demographic and pregnancy characteristics. Significant associations were included in a multivariable logistic regression, which accounted for multiple pregnancies derived from the same respondent.

RESULTS

A total of 12,710 pregnancies from 6979 women were analyzed, consisting of 2300 (18.2%) spontaneous abortions and 10,410 (81.8%) term live births. Median maternal and paternal ages were 25 and 28 years, respectively. After adjusting for maternal age, race/ethnicity, socioeconomic status, marital status, and pregnancy intention, pregnancies resulting in spontaneous abortions had 2.05 (95% confidence interval, 1.06-2.20) times the odds of being from a father aged 50 years or older, vs. 25-29 years of age. These relationships remained significant when defining SABs at ≤12 weeks (adjusted odds ratio, 2.30; 95% confidence interval, 1.17-4.52).

CONCLUSION

Paternal age may increase the odds of spontaneous abortion, independent of selected factors, including demographics, pregnancy intention, and maternal age. This association was robust across several gestational age-based definitions of spontaneous abortion, even after adjustment.

Post-copulatory sexual selection allows females to alleviate the fitness costs incurred when mating with senescing males

Male senescence has detrimental effects on reproductive success and offspring fitness. When females mate with multiple males during the same reproductive bout, post-copulatory sexual selection that operates either through sperm competition or cryptic female choice might allow females to skew fertilization success towards young males and as such limit the fitness costs incurred when eggs are fertilized by senescing males. Here, we experimentally tested this hypothesis. We artificially inseminated female North African houbara bustards with sperm from dyads of males of different (young and old) or similar ages (either young or old). Then, we assessed whether siring success was biased towards young males and we measured several life-history traits of the progeny to evaluate the fitness costs due to advanced paternal age. In agreement with the prediction, we found that siring success was biased towards young males, and offspring sired by old males had impaired hatching success, growth and post-release survival (in females). Overall, our results support the hypothesis that post-copulatory sexual selection might represent an effective mechanism allowing females to avoid the fitness costs of fertilization by senescing partners.

Parental age and child outcomes

This review summarizes the impact of parental age on children's health outcomes beyond the perinatal period. In the last decades, delayed parenthood with both men and women has become a public health issue. For women, in particular, the size of this delay is substantial. For a few medical conditions, older parental age has a pronounced effect on child morbidity. For most other outcomes, a more modest effect is evident. Although these effects might be limited on an individual level, they have a substantial impact at the level of population health.

Paternal age contribution to brain white matter aberrations in autism spectrum disorder

AIM

Although advanced parental age holds an increased risk for autism spectrum disorder (ASD), its role as a potential risk factor for an atypical white matter development underlying the pathophysiology of ASD has not yet been investigated. The current study was aimed to detect white matter disparities in ASD, and further investigate the relationship of paternal and maternal age at birth with such disparities.

METHODS

Thirty-nine adult males with high-functioning ASD and 37 typically developing (TD) males were analyzed in the study. The FMRIB Software Library and tract-based spatial statistics were utilized to process and analyze the diffusion tensor imaging data.

RESULTS

Subjects with ASD exhibited significantly higher mean diffusivity (MD) and radial diffusivity (RD) in white matter fibers, including the association (inferior fronto-occipital fasciculus, right inferior longitudinal fasciculus, superior longitudinal fasciculi, uncinate fasciculus, and cingulum), commissural (forceps minor), and projection tracts (anterior thalamic radiation and right corticospinal tract) compared to TD subjects (Padjusted  < 0.05). No differences were seen in either fractional anisotropy or axial diffusivity. Linear regression analyses assessing the relationship between parental ages and the white matter aberrations revealed a positive correlation between paternal age (PA), but not maternal age, and both MD and RD in the affected fibers (Padjusted  < 0.05). Multiple regression showed that only PA was a predictor of both MD and RD.

CONCLUSION

Our findings suggest that PA contributes to the white matter disparities seen in individuals with ASD compared to TD subjects.

Disease burden in offspring is associated with changing paternal demographics in the United States

BACKGROUND

Average paternal age in the United States has increased substantially in the last few decades. Children of advanced age fathers have a higher incidence of early onset cancer and neuropsychiatric disease.

OBJECTIVES

To quantify the number of population adjusted cases of early-onset cancer and neuropsychiatric disease in children attributable to increasing paternal age in the United States.

METHODS

Paternal age in the United States from 1972 to 2015 was collected using the National Vital Statistics System (NVSS). Population attributable fraction and paternal age-specific cumulative incidence rates of several cancers and neuropsychiatric disorders were obtained from peer-reviewed publications. Paternal age-specific birth rates were correlated with paternal age-specific cumulative incidence rates to determine the number of attributable cases of disease caused by advancing age of fathers in the United States.

RESULTS

The 2015 birth cohort in the United States is estimated to expect 9.2% more cases of acute lymphoblastic leukemia (ALL) diagnosed before 16 years of age (157 additional cases), 13.2% more cases of embryonal tumors in children <5 years of age (209 additional cases), and 13.0% more cases of breast cancer in females younger than 40 years old (424 additional cases) compared to the 1972 birth cohort. We can estimate to expect 10.5% more cases of schizophrenia diagnosed before 21 years of age (2864 additional cases), 6.3% more cases of autism spectrum disorder (ASD) in adolescents <17 years of age (2934 additional cases), 4.5% more cases of anorexia nervosa (AN) in females 8-30 years old (620 additional cases), and 9.2% more cases of bipolar disorder in young patients 16-25 years old (252 additional cases) in the 2015 birth cohort compared to the 1972 birth cohort.

CONCLUSION

Increasing paternal age in the United States is associated with a substantial increase in the number of cases of early-onset cancer and neuropsychiatric disease in offspring.

Age-related changes in human sperm DNA integrity

Abnormal standard semen characteristics and reduced sperm chromatin maturity can appear with increasing male age. However, the influence of paternal age on semen parameters is still controversial. Therefore, this study was designed to estimate the influence of paternal age not only on conventional semen characteristics but also on sperm DNA integrity. This research was carried out on ejaculated sperm cells obtained from men (n = 1124) aged ≥40 y and <40 y. Our data revealed a decreased semen volume and an increased percentage of DFI (sperm DNA fragmentation index) in older men compared to younger men in the entire study cohort, in men with normozoospermia and in men with abnormal semen parameters. Moreover, there was a higher incidence of sperm DNA damage (>10% DFI, low fertility potential) in the groups of men aged ≥40 y than in the groups of men aged <40 y. Older men had over twice the odds ratio for high sperm DNA damage as younger men. Our findings suggest a detrimental effect of advanced paternal age on sperm chromatin integrity. The data show that the evaluation of sperm DNA has greater clinical utility than standard semen analysis in case of male fertility potential assessment.