Is advanced paternal age a health risk for the offspring?

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

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

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

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

The "Bad Father": Paternal Role in Biology of Pregnancy and in Birth Outcome

Pregnancy is generally studied as a biological interaction between a mother and a fetus; however, the father, with his characteristics, lifestyle, genetics, and living environment, is by no means unrelated to the outcome of pregnancy. The half of the fetal genetic heritage of paternal derivation can be decisive in cases of inherited chromosomal disorders, and can be the result of de novo genetic alterations. In addition to the strictly pathological aspects, paternal genetics may transmit thrombophilic traits that affect the implantation and vascular construction of the feto-placental unit, lead to placenta-mediated diseases such as pre-eclampsia and fetal growth retardation, and contribute to the multifactorial genesis of preterm delivery. Biological aspects of immunological tolerance to paternal antigens also appear to be crucial for these pathologies. Finally, this review describes the biological findings by which the environment, exposure to pathogens, lifestyle, and nutritional style of the father affect fetal pathophysiological and epigenetic definition.

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.

The role of fathers in child development from preconception to postnatal influences: Opportunities for the National Institutes of Health Environmental influences on Child Health Outcomes (ECHO) program

A growing body of literature highlights the important role of paternal health and socioemotional characteristics in child development, from preconception through adolescence. Much of this research addresses the indirect effects of fathers, for instance, their influence on maternal behaviors during the prenatal period or via the relationship with their partner. However, emerging evidence also recognizes the direct role of paternal health and behavior for child health and adjustment across development. This critical review presents evidence of biological and sociocultural influences of fathers on preconception, prenatal, and postnatal contributions to child development. The National Institutes of Health Environmental influences on Child Health Outcomes (ECHO) program incorporates in its central conceptualization the impact of fathers on family and child outcomes. This critical synthesis of the literature focuses on three specific child outcomes in the ECHO program: health outcomes (e.g., obesity), neurodevelopmental outcomes (e.g., emotional, behavioral, psychopathological development), and positive health. We highlight the unique insights gained from the literature to date and provide next steps for future studies on paternal influences.

Association of pre-existing maternal cardiovascular diseases with neurodevelopmental disorders in offspring: a cohort study in Sweden and British Columbia, Canada

BACKGROUND

We aimed to investigate the associations of pre-existing maternal cardiovascular disease (CVD) with attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and intellectual disability (ID) in offspring.

METHODS

This population-based cohort study included singletons live-born without major malformations in Sweden (n = 2 699 675) and British Columbia (BC), Canada (n = 887 582) during 1990-2019, with follow-up from age 1 year until the outcome, death, emigration or December 2020, whichever came first. The primary exposure was defined as a composite CVD diagnosed prior to conception: cerebrovascular disease, arrhythmia, heart failure, valvular and congenital heart diseases. The incidences of ADHD, ASD and ID, comparing offspring of mothers with versus without CVD, were calculated as adjusted hazard ratios (aHRs). These results were compared with models using paternal CVD as negative control exposure.

RESULTS

Compared with offspring of mothers without CVD, offspring of mothers with CVD had 1.15-fold higher aHRs of ADHD [95% confidence interval (CI): 1.10-1.20] and ASD (95% CI 1.07-1.22). No association was found between maternal CVD and ID. Stratification by maternal CVD subtypes showed increased hazards of ADHD for maternal heart failure (HR 1.31, 95% CI 1.02-1.61), cerebrovascular disease (HR 1.20, 95% CI 1.08-1.32), congenital heart disease (HR 1.18, 95% CI 1.08-1.27), arrhythmia (HR 1.13, 95% CI 1.08-1.19) and valvular heart disease (HR 1.12, 95% CI 1.00-1.24). Increased hazards of ASD were observed for maternal cerebrovascular disease (HR 1.25, 95% CI 1.04-1.46), congenital heart disease (HR 1.17, 95% CI 1.01-1.33) and arrythmia (HR 1.12, 95% CI 1.01-1.21). Paternal CVD did not show associations with ADHD, ASD or ID, except for cerebrovascular disease which showed associations with ADHD and ASD.

CONCLUSIONS

In this large cohort study, pre-existing maternal CVD was associated with increased risk of ADHD and ASD in offspring.

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.

Parental age at birth and biomarkers of fecundity in young Danish men

BACKGROUND

High parental age is associated with adverse birth and genetic outcomes, but little is known about fecundity in male offspring.

OBJECTIVES

We investigated if high parental age at birth was associated with biomarkers of male fecundity in a large population-based sample of young men.

MATERIALS AND METHODS

We conducted a study of 1057 men from the Fetal Programming of Semen Quality (FEPOS) cohort, a sub-cohort of sons born 1998-2000 into the Danish National Birth Cohort. Semen characteristics and reproductive hormone concentrations were measured in samples provided by the men 2017-2019. Testis volume was determined by self-measurement. Data on the parental age was drawn from registers. Adjusted relative difference in percentage with 95% confidence intervals were estimated for each outcome according to pre-specified maternal and paternal age groups (< 30 (reference), 30-34 and ≥ 35) as well as for combinations of parental age groups, using multivariable negative binomial regression models.

RESULTS

We did not observe consistent associations between parental age and biomarkers of fecundity, although sons of mothers ≥ 35 years had lower sperm concentration (-15% (95% CI: -30, 3)) and total sperm count (-10% (95% CI: -25, 9)). The analysis with parental age combinations showed lower sperm concentration with high age of the parents (both ≥ 35 years: -27%, 95% CI: -40, -19) when compared to the reference where both parents were below 30 years.

DISCUSSION AND CONCLUSION

We found no strong association between higher parental age and biomarkers of fecundity in young men. However, we cannot exclude poorer semen characteristics in sons born by older mothers or with high age of both parents.

Methotrexate use among men-association with fertility and the perinatal health of their children: a Swedish nationwide register study

OBJECTIVE

To study the effect of methotrexate on male fertility and subsequent effects on their children, for which data are scarce and contradictory.

DESIGN

Nationwide multiregister cohort study.

SETTING

Not applicable.

SUBJECT(S)

All children born alive in Sweden between 2006 and 2014 and their fathers. Three cohorts were defined: children to fathers with periconceptional methotrexate exposure (exposed cohort), children whose fathers stopped methotrexate intake ≥2 years before conception (previously exposed cohort), and children to fathers with no methotrexate exposure (control cohort).

EXPOSURE(S)

The father having at least one dispensed methotrexate prescription from pharmacies 0-3 months before conception, along with at least one more dispensed methotrexate prescription 0-12 months before conception (periconceptional exposure). Previously exposed cohort: the father having no dispensed methotrexate prescriptions in the 2 years before conception, but having at least two dispensed prescriptions before that.

MAIN OUTCOME MEASURES

Congenital anomalies (major and any; primary outcomes), preterm birth (PTB) and being small for gestational age (SGA; secondary outcomes), as well as need of intracytoplasmic sperm injection (ICSI) to achieve pregnancy (primary outcome in exposed cohort vs. controls, exploratory outcome in previously exposed cohort vs. controls). Outcomes were analyzed using logistic regression.

RESULTS

A total of 223 children to fathers with periconceptional methotrexate exposure were identified, along with 356 children whose fathers stopped methotrexate intake ≥2 years before conception and 809,706 not methotrexate-treated controls. In children with fathers periconceptionally exposed to methotrexate, the adjusted and unadjusted odds ratios (95% confidence intervals) for major congenital anomalies were 1.1 (0.4-2.6) and 1.1 (0.4-2.4), any congenital anomalies 1.3 (0.7-2.4) and 1.4 (0.7-2.3), PTB 1.0 (0.5-1.8) and 1.0 (0.5-1.8), SGA 1.1 (0.4-2.6) and 1.0 (0.4-2.2), and conception by use of ICSI 3.9 (2.2-7.1) and 4.6 (2.5-7.7). Use of ICSI was not increased among fathers who stopped methotrexate intake ≥2 years before conception, having adjusted and unadjusted odds ratios 0.9 (0.4-1.9) and 1.5 (0.6-2.9).

CONCLUSION

This study suggests that paternal periconceptional methotrexate use does not increase risk of congenital anomalies, PTB, or SGA in the offspring but may temporarily reduce fertility.

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

BACKGROUND

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

OBJECTIVE

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

MATERIAL AND METHODS

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

RESULTS

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

DISCUSSION AND CONCLUSION

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

The effect of advanced paternal age on the lifespan of male offspring in an ancient Chinese genealogical data set

BACKGROUND

Advanced paternal age has been reported to be associated with a variety of short-term outcomes in offspring, but long-term effects are rarely examined. The present study evaluated the impact of advanced paternal age on offspring's longevity.

METHODS

We studied the effect of paternal reproductive age on the lifespan of male offspring using a Chinese genealogy data set that spans 226 years of the Qing Dynasty (1683-1909). Multivariable-adjusted Cox regression analyses of 1274 men with survival data were used to calculate hazard ratios (HRs) of advanced parental age at reproduction. We also evaluated whether the lifespan of brothers differed when they were born to the same parents at different ages.

RESULTS

In models adjusted for maternal age, advanced paternal age was negatively associated with the lifespan of male offspring. Individuals born to fathers aged >40 years had a 32 % higher HR of a lifespan shorter than those born to fathers aged 25-29 years (adjusted HR 1.320, 95 % CI: 1.066-1.634). The adjusted HR for offspring born to fathers aged 35-39 years was 1.232 (95 % CI: 1.013-1.500). Older brothers born to fathers aged 20-34 years had a significantly lower risk of a reduced lifespan compared with their younger brothers with fathers aged ≥35 years at reproduction (P < 0.01).

CONCLUSION

Advanced paternal age at reproduction is a negative factor for male offspring's life expectancy. With the sustained increase in paternal age over the past generation, further investigation is warranted into the impact on birth outcomes and public health.

Animal models of male reproductive ageing to study testosterone production and spermatogenesis

Ageing is the time-dependent gradual decline of the functional characteristics in an organism. It has been shown that it results in the loss of reproductive health and fertility. The age-dependent decline of fertility is a potential issue as the parenthood age is increasing in Western countries, mostly due to socioeconomic factors. In comparison to women, for whom the consequences of ageing are well documented and general awareness of the population is extensively raised, the effects of ageing for male fertility and the consequences of advanced paternal age for the offspring have not been widely studied. Studies with humans are welcome but it is hard to implement relevant experimental approaches to unveil the molecular mechanisms by which ageing affects male reproductive potential. Animal models have thus been extensively used. These models are advantageous due to their reduced costs, general easy maintenance in laboratory facilities, rigorous manipulation tools, short lifespan, known genetic backgrounds, and reduced ethical constraints. Herein, we discuss animal models for the study of male reproductive ageing. The most well-known and studied reproductive ageing models are rodents and non-human primates. The data collected from these models, particularly studies on testicular ageing, steroidogenesis, and genetic and epigenetic changes in spermatogenesis are detailed. Notably, some species challenge the currently accepted ageing theories and the concept of senescence itself, which renders them interesting animal models for the study of male reproductive ageing.

Effect of advanced parental age on pregnancy outcome and offspring health

PURPOSE

Fertility at advanced age has become increasingly common, but the aging of parents may adversely affect the maturation of gametes and the development of embryos, and therefore the effects of aging are likely to be transmitted to the next generation. This article reviewed the studies in this field in recent years.

METHODS

We searched the relevant literature in recent years with the keywords of "advanced maternal/paternal age" combined with "adverse pregnancy outcome" or "birth defect" in the PubMed database and classified the effects of parental advanced age on pregnancy outcomes and birth defects. Related studies on the effect of advanced age on birth defects were classified as chromosomal abnormalities, neurological and psychiatric disorders, and other systemic diseases. The effect of assisted reproduction technology (ART) on fertility in advanced age was also discussed.

RESULTS

Differences in the definition of the range of advanced age and other confounding factors among studies were excluded, most studies believed that advanced parental age would affect pregnancy outcomes and birth defects in offspring.

CONCLUSION

To some extent, advanced parental age caused adverse pregnancy outcomes and birth defects. The occurrence of these results was related to the molecular genetic changes caused by aging, such as gene mutations, epigenetic variations, etc. Any etiology of adverse pregnancy outcomes and birth defects related to aging might be more than one. The detrimental effect of advanced age can be corrected to some extent by ART.

Fertility preservation for patients with melanoma

The advent of immunotherapy and targeted therapy has outstandingly improved the prognosis in subjects with melanoma. Their use is now advocated also in earlier stages as an adjuvant therapy, and some neoadjuvant clinical trials are ongoing. Consequently, survivors free of disease are increasing, as well as those exposed to these new agents. Parenthood in survivors is, therefore, receiving growing interest. Evidence on the effects of immunotherapy and targeted therapy on future fertility is limited, but not entirely reassuring, in particular for immunotherapy. The necessity of delaying pregnancy seeking up to the end of treatments and follow-up (iatrogenic aging) is an additional albeit neglected source of concern, in particular for women in their late 30s. Subjects with melanoma should be informed on the multifaceted issue of future fertility at the time of cancer diagnosis. Available options of fertility preservations, including sperm and oocytes storage, should also be discussed, especially considering that at the age 0-39, melanoma represents the second most frequent neoplasia. In the decision-making process, most attention should be given to sex, age, and exposure to immunotherapy.

Germline De Novo Mutations as a Cause of Childhood Cancer

Germline de novo mutations (DNMs) represent one of the important topics that need extensive attention from epidemiologists, geneticists, and other relevant stakeholders. Advances in next-generation sequencing technologies allowed examination of parent-offspring trios to ascertain the frequency of germline DNMs. Many epidemiological risk factors for childhood cancer are indicative of DNMs as a mechanism. The aim of this review was to give an overview of germline DNMs, their causes in general, and to discuss their relation to childhood cancer risk. In addition, we highlighted existing gaps in knowledge in many topics of germline DNMs in childhood cancer that need exploration and collaborative efforts.

OBGYN providers' lack of knowledge and management of genetic risks due to advanced paternal age underscore the need for updated practice guidance

The objective of this pilot study was to characterize healthcare professionals' knowledge of advanced paternal age (APA), the associated risks, as well as current clinical practices regarding APA. Our study utilized an online survey that questioned providers who see children with genetic conditions and patients who are or may become pregnant regarding demographic information, APA knowledge, APA guideline familiarity, and their clinical practices. A total of 67 providers responded to the survey. We had responses from 54 physician participants in the specialties of medical genetics (GEN), maternal fetal medicine (MFM), and obstetrics and gynecology (OBGYN). OBGYN, but not MFM, reported significantly lower agreement that current data supports an association between APA and certain genetic diseases compared to GEN. Furthermore, OBGYN were less likely to identify established risks associated with APA and more likely to incorrectly identify unestablished risks compared to GEN and MFM. Regardless of specialty, the majority of physicians were unfamiliar with the most recently published APA guidelines. This study revealed a desire for more information regarding APA risks and management among our participants. Our data suggest that GEN, MFM, and OBGYN would benefit from updated and more visible guidelines regarding APA. Additionally, OBGYN consistently showed knowledge gaps and misconceptions regarding the risks of APA. Targeted educational or guidance materials regarding APA may also be beneficial for OBGYNs.

Normal-Range Paternal Serum-Free Thyroxine Concentrations and Outcomes of Assisted Reproductive Technologies

Background: A recent study showed that paternal subclinical hypothyroidism adversely affects the clinical outcomes of assisted reproductive technologies (ARTs). The aim of this study was to determine whether paternal serum-free thyroxine (fT4) concentrations within the reference range are associated with ART outcomes. Methods: This retrospective cohort study included 4066 couples who received 4894 ART treatment cycles in our clinic between April 1, 2016 and August 31, 2021. The differences in sperm parameters and ART outcomes across the paternal fT4 concentration tertiles were compared by using generalized linear models or generalized estimation equation models. The primary outcomes were clinical pregnancy rate (CPR) and live birth rate (LBR) per oocyte retrieval after the first embryo transfer cycle. Results: The mean ages of the males and their female partners were 32.8 (standard deviation, 5.0) and 30.7 (standard deviation, 4.1) years, respectively. No significant differences were observed in the sperm parameters or ART outcomes between the paternal fT4 concentration tertiles of the overall population. However, a stratified analysis of men aged ≥35 showed an adjusted CPR of 0.36 [confidence interval, CI: 0.27-0.45] for the lower paternal fT4 concentration tertile relative to the middle (adjusted rate: 0.45, CI: 0.38-0.53) and upper (adjusted rate: 0.43, CI: 0.36-0.51) tertiles (p for trend >0.05). The adjusted LBRs were 0.21 [CI: 0.15-0.30] for men aged ≥35 in the lower fT4 concentration tertile (p = 0.024, with reference to the upper tertile), 0.27 [CI: 0.21-0.35] for those in the middle tertile, and 0.30 [CI: 0.23-0.38] for those in the upper tertile. No differences in these outcomes were observed in men aged <35. The nonlinear smoothing curve obtained by using fT4 concentration as a continuous variable further supported these findings. Conclusions: Men of older reproductive age (≥35 years old) with low-normal fT4 concentrations within the reference range are associated with a decreased LBR. Future prospective studies are warranted to confirm the detrimental effects of low-normal paternal fT4 concentrations on ART outcomes.

Environmental factors in declining human fertility

A severe decline in child births has occurred over the past half century, which will lead to considerable population declines, particularly in industrialized regions. A crucial question is whether this decline can be explained by economic and behavioural factors alone, as suggested by demographic reports, or to what degree biological factors are also involved. Here, we discuss data suggesting that human reproductive health is deteriorating in industrialized regions. Widespread infertility and the need for assisted reproduction due to poor semen quality and/or oocyte failure are now major health issues. Other indicators of declining reproductive health include a worldwide increasing incidence in testicular cancer among young men and alterations in twinning frequency. There is also evidence of a parallel decline in rates of legal abortions, revealing a deterioration in total conception rates. Subtle alterations in fertility rates were already visible around 1900, and most industrialized regions now have rates below levels required to sustain their populations. We hypothesize that these reproductive health problems are partially linked to increasing human exposures to chemicals originating directly or indirectly from fossil fuels. If the current infertility epidemic is indeed linked to such exposures, decisive regulatory action underpinned by unconventional, interdisciplinary research collaborations will be needed to reverse the trends.

Social, demographic and health characteristics of men fathering children at different ages

The aim of this study was to examine associations between selected sociodemographic, socioeconomic, and health characteristics and the rates of fatherhood in different age groups. We investigated rates between 2011 and 2015 in a population-based register study including all men born from 1945 to 1995 residing in Denmark in 2011. The study population consisted of 1,867,108 men who fathered 268,612 children during the follow-up. The associations were quantified as incidence rate ratios using Poisson regression. Young men had higher rates of fathering a child if they lived outside the Capital Region, had a relatively high income, were previously diagnosed with cardiovascular disease, psychoactive substance abuse, personality disorders, schizophrenia or behavioural and emotional disorders. Men of advanced age had higher rates of fathering a child when born outside Denmark, living in the Capital Region, were in the lower or upper 10th percentile income group, were self-employed or unemployed or previously diagnosed with depression. Men of advanced age had lower rates of fathering a child if previously diagnosed with somatic diseases, psychoactive substance abuse or mental retardation. The findings highlight the importance of consideration of various sociodemographic, socioeconomic, and health characteristics when studying associations between paternal age and offspring health.

Altered sperm tsRNAs in aged male contribute to anxiety-like behavior in offspring

Parental age at first pregnancy is increasing worldwide. The offspring of aged father has been associated with higher risk of several neuropsychiatric disorders, such as schizophrenia and autism, but the underlying mechanism remains elusive. Here we report that advanced paternal age in mice alters the profile of transfer RNA‐derived small RNAs (tsRNAs). Injection of sperm tsRNAs from aged male mice into zygotes induced anxiety‐like behaviors in F1 males. RNA sequencing of the cerebral cortex and hippocampus of those F1 male mice altered the gene expression of dopaminergic synapse and neurotrophin. tsRNAs from aged male mice injection also altered the neuropsychiatry‐related gene expression in two‐cell and blastocyst stage embryos. More importantly, the sperm tsRNA profile changes significantly during aging in human. The up‐regulated sperm tsRNA target genes were involved in neurogenesis and nervous system development. These results suggest that aging‐related changes of sperm tsRNA may contribute to the intergenerational transmission of behavioral traits.

Birth defects surveillance after assisted reproductive technology in Beijing: a whole of population-based cohort study

OBJECTIVES

To compare the differences in the prevalence of birth defects among offspring conceived by assisted reproductive technology (ART) and conceived spontaneously (non-ART), and assess the contribution of ART to birth defects.

DESIGN

A population-based retrospective cohort study.

SETTING

Beijing.

PARTICIPANTS

Pregnant women whose expected date of childbirth was verified as occurring between October 2014 and September 2015, and were registered on the Beijing Maternal and Child Health Information Network System, were the recorded pregnancy outcomes. 2699 ART offspring and 191 368 non-ART offspring (live births, stillbirths and medical terminations) were included in our study.

INTERVENTIONS

None.

OUTCOME MEASURES

Risk ratios (RR) for birth defects were calculated among ART conceptions and non-ART conceptions with confounding factors by using logistic regression models.

RESULTS

194 067 offspring were included in the present study, and 2699 (1.4%) were conceived using ART. Among all the births, the prevalence of any birth defect in the ART offspring (5.5%) was significantly higher than in the non-ART offspring (3.8%) (crude RR, 1.49, 95% CI 1.26 to 1.76). After adjusting for confounding factors, ART use was still associated with an increased risk of any birth defect (5.4% vs 3.5% in ART and non-ART group, adjusted RR (aRR), 1.43, 95% CI 1.08 to 1.90), especially for chromosomal abnormalities (0.5% vs 0.2% in ART and non-ART group, aRR, 3.11, 95% CI 1.28 to 7.58), in singleton births to mothers <35 years. Circulatory system malformations and musculoskeletal system malformations were observed to have a non-significant increase in offspring conceived by ART. However, the associations between ART and birth defects were not detected in multiple births or mothers ≥35 years.

CONCLUSIONS

This study confirmed a small but significant association between ART and birth defects. However, the risk tends to be non-significant under the conditions of advanced maternal age or multiple pregnancies.

The influence of parental age on timing of puberty: A study in the Danish National Birth Cohort

Aims: Concerns have been raised about the potential negative biological effect of postponed parenthood upon the health of subsequent generations, including reproductive health. This study aimed to estimate if high parental age at birth was associated with accelerated pubertal timing in offspring. Methods: In this large-scale cohort study, 15,819 children born by mothers in the Danish National Birth Cohort from 2000 to 2003 participated in a nationwide puberty cohort (participation rate 71%). Between 2012 and 2018, the children reported half-yearly information on pubertal status using web-based questionnaires from 11 years throughout puberty or 18 years of age. Information on parental age was drawn from nationwide registers. We estimated adjusted mean differences in months for age at attaining the pubertal milestones and pubertal timing overall between the pre-specified parental age groups: 20-29 (reference), 30-34 and advanced parental age groups (35-44 years for mothers and >35 years for fathers). Results: Overall, parental age at birth of the child was not associated with pubertal timing in daughters or sons. For sons of older fathers (>35 years), we observed indications towards slightly earlier pubertal timing in the range of 0.3-2.4 months for nearly all pubertal milestones, but all confidence intervals were wide, and many included the null. Conclusions: We found no strong association between parental age and timing of puberty, and we find it unlikely that the decreasing age in pubertal timing is a result of parental decision to delay childbearing.

Heterogenous effects of father and mother age on offspring development

Maternal age has long been described to influence a broad range of offspring life-history traits, including longevity. However, relatively few studies have tested experimentally for the effects of paternal age and even fewer the potential interactive effects of father and mother age on offspring life-history traits from conception to death. To tackle these questions, I performed a factorial experimental design where I manipulated the age of both male and female field crickets (Gryllus bimaculatus) and subsequently assessed their effects over the offspring’s entire lifetime. I found that, despite coming from larger eggs, the embryos of old females grew up at a slower rate, took more time to develop, and showed lower hatching success than those of young females. Offspring postnatal viability was unaffected by female age but, at adulthood, the offspring of old females were bigger and lived shorter than those of young females. Male age effects were mostly present during offspring postnatal development as nymphs sired by old males having increased early mortality. Moreover, father age strongly influenced the development of offspring adult personality as revealed by the shyer personality of crickets sired by an old male. My results indicate that father and mother age at reproduction have different effects that affect offspring traits at different stages of their development. The results further suggest that father and mother age effects could be mediated by independent mechanisms and may separately influence the evolution of aging.

Aging-induced changes in sperm DNA methylation are modified by low dose of perinatal flame retardants

Aims: Paternal age is increasing in developed countries. Understanding of aging-related epigenetic changes in sperm is needed as well as factors that modify such changes. Materials & methods: Young pubertal and mature rats were exposed perinatally to vehicle or environmental xenobiotic 2,2',4,4'-tetrabromodiphenyl ether. Epididymal sperm was reduced representation bisulfite sequenced. Differentially methylated regions (DMRs) were identified via MethPipe. Results: In control animals, 5319 age-dependent DMRs were identified. Age-related DMRs were enriched for embryonic development. In exposed rats, DNA methylation was higher in young and lower in mature animals then in controls. Conclusions: Sperm methylome undergoes significant age-dependent changes, which may represent a causal link between paternal age and offspring phenotype. Environmental xenobiotics can interfere with the natural process of epigenetic aging.

Parental age at childbirth and risk for attention-deficit/hyperactivity disorder in offspring

This study investigated the association between parental age at birth and attention-deficit/hyperactivity disorder (ADHD) symptoms in their children. A total of 30,552 children aged 6-12 years participated in the study. ADHD symptoms were rated using the Korean version of the ADHD Rating Scale (K-ARS) by parents. K-ARS scores and odds ratio (OR) for children with high-risk ADHD presented a U-shape curve depending on the age of both parents at birth. The total K-ARS scores and OR for high-risk ADHD were highest in children of fathers and mothers belonging to the youngest age group (aged ≤20) (K-ARS = 12.33, OR = 2.89 vs K-ARS = 10.98, OR = 2.63) and second highest in children whose father's or mother's age at birth was the oldest (K-ARS = 9.63, OR = 1.65 vs K-ARS = 9.95, OR = 1.95). Our study identified that both spectrums of age-young and old of either parent-were associated with ADHD in children. These are new findings considering that old age of parents as the correlates of offspring ADHD is the inconsistent finding with previous studies and warrant future studies in other cultures that include more detailed information on ADHD symptoms of children and their parents are needed to confirm the present findings.

Advanced parental age: Is it contributing to an increased incidence of non-syndromic craniosynostosis? A review of case-control studies

Background

Craniosynostosis (CS) is a congenital birth defect characterized by the premature fusion of one or several calvarial suture(s). CS could lead to serious complications, such as intracranial hypertension and neurodevelopmental impairment. There is an increasing trend in the prevalence of CS - 75% of which are of non-syndromic type (NSCS). In parallel, there is a steady rise in the average maternal age. The goal of this paper was to review the literature to clearly identify any associations between parental age and NSCS. This review was performed and reported in compliance with PRISMA guidelines.

Methods

The PUBMED and EMBASE databases were systematically searched, and all studies that observed the relationship between maternal and/or paternal age on NSCS were included. The articles were then assessed for methodological quality using the Newcastle-Ottawa Scale (NOS). The effect of advanced maternal and/or paternal age on the incidence of NSCS was identified by the prevalence ratios reported at a confidence interval of 95%.

Results

Six retrospective case-control studies, reporting on a total of 3267 cases of NSCS were included in this review. While there were some inconsistencies in the findings of the different studies, the majority reported a positive correlation between advanced maternal and/or paternal age and an increased incidence of NSCS.

Conclusion

This review identified an association between advanced parental age and an increased incidence of NSCS.

The Sins of Our Forefathers: Paternal Impacts on De Novo Mutation Rate and Development

Spermatogonial stem cells (SSCs) are generally characterized by excellent DNA surveillance and repair, resulting in one of the lowest spontaneous mutation rates in the body. However, the barriers to mutagenesis can be overwhelmed under two sets of circumstances. First, replication errors may generate age-dependent mutations that provide the mutant cells with a selective advantage, leading to the clonal expansions responsible for dominant genetic diseases such as Apert syndrome and achondroplasia. The second mechanism centers on the vulnerability of the male germline to oxidative stress and the induction of oxidative DNA damage in spermatozoa. Defective repair of such oxidative damage in the fertilized oocyte results in the creation of mutations in the zygote that can influence the health and well-being of the offspring. A particular hot spot for such oxidative attack on chromosome 15 has been found to align with several mutations responsible for paternally mediated disease, including cancer, psychiatric disorders, and infertility.

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.

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

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

Aging Induces Profound Changes in sncRNA in Rat Sperm and These Changes Are Modified by Perinatal Exposure to Environmental Flame Retardant

Advanced paternal age at fertilization is a risk factor for multiple disorders in offspring and may be linked to age-related epigenetic changes in the father's sperm. An understanding of aging-related epigenetic changes in sperm and environmental factors that modify such changes is needed. Here, we characterize changes in sperm small non-coding RNA (sncRNA) between young pubertal and mature rats. We also analyze the modification of these changes by exposure to environmental xenobiotic 2,2',4,4'-tetrabromodiphenyl ether (BDE-47). sncRNA libraries prepared from epididymal spermatozoa were sequenced and analyzed using DESeq 2. The distribution of small RNA fractions changed with age, with fractions mapping to rRNA and lncRNA decreasing and fractions mapping to tRNA and miRNA increasing. In total, 249 miRNA, 908 piRNA and 227 tRNA-derived RNA were differentially expressed (twofold change, false discovery rate (FDR) p ≤ 0.05) between age groups in control animals. Differentially expressed miRNA and piRNA were enriched for protein-coding targets involved in development and metabolism, while piRNA were enriched for long terminal repeat (LTR) targets. BDE-47 accelerated age-dependent changes in sncRNA in younger animals, decelerated these changes in older animals and increased the variance in expression of all sncRNA. Our results indicate that the natural aging process has profound effects on sperm sncRNA profiles and this effect may be modified by environmental exposure.

Do the ages of parents or helpers affect offspring fitness in a cooperatively breeding bird?

Age-related changes in parental phenotypes or genotypes can impact offspring fitness, but separating germline from nongermline transgenerational effects of ageing is difficult for wild populations. Further, in cooperatively breeding species, in addition to parental ages, the age of 'helpers' attending offspring may also affect juvenile performance. Using a 30-year study of a cooperative breeder with very high rates of extra-pair paternity, the superb fairy-wren (Malurus cyaneus), we investigated the effects of maternal, paternal and helper ages on three measures of offspring performance: nestling weight, juvenile survival to independence and recruitment to the breeding population. Mothers with a longer lifespan had offspring with higher juvenile survival, indicating selective disappearance, but the effect of maternal age on juvenile survival was of similar magnitude but negative. For extra-pair offspring, there was no evidence of any effect of the ages of either the genetic sire or the cuckolded 'social' father. However, for within-pair offspring, there was a positive effect of paternal age on juvenile survival, which we suggest may be driven by sexual selection. There were positive associations between the average age of helpers attending a nest and two of the three aspects of offspring performance; these effects were stronger than any of the effects of parental age. In general, the multiple associations between offspring fitness and the ages of adults around them appeared to be driven more by age-related changes in environmental effects than by age-related changes in the germline.

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.

The risks of advancing parental age on neonatal morbidity and mortality are U- or J-shaped for both maternal and paternal ages

BACKGROUND

The biologic implications of delayed parenthood have been blamed for a major public health crisis in the United States, that includes high rates of neonatal morbidity and mortality (NMM). The objective of this study was to evaluate the risk of parent age on NMM and to provide results that can serve as a starting point for more specific mediation modeling.

METHODS

Data containing approximately 15,000,000 birth records were obtained from the United States Natality database for the years 2014 to 2018. A Bayesian modeling approach was used to estimate the both the total effect and the risk adjusted for confounding between parent ages and for mediation by chromosomal disorders including Down syndrome. Outcomes included intra-hospital death and nine measures of neonatal morbidity.

RESULTS

For paternal age, seven NMM (preterm birth, very preterm birth, low Apgar score, treatment with antibiotics, treatment with surfactant, prolonged ventilation, intra-hospital death) had U-shaped risk patterns, two NMM (small for gestational age, admission to neonatal intensive care) had J-shaped risk patterns, one NMM (seizures) was not significantly related to paternal age. For maternal age, three NMM (low Apgar score, treatment with antibiotics and intra-hospital death) had U-shaped risk patterns, four NMM (preterm delivery, very preterm delivery, admission to neonatal intensive care, treatment with surfactant) had J-shaped risk patterns, one NMM (small for gestational age) had a risk declining with age, one NMM (prolonged ventilation) had a risk increasing with age and one NMM (seizures) was not significantly related to maternal age.

CONCLUSIONS

Both advancing maternal and paternal ages had U- or J-shaped risk patterns for neonatal morbidity and mortality.

Genetic counseling for advanced paternal age: A survey of genetic counselors' current practice

Advanced paternal age (APA) has no formal definition, though many publications utilize the cutoff of fathers >40 years of age. The literature demonstrates an association between APA and certain conditions including de novo autosomal dominant disorders, birth defects, and neuropsychiatric conditions. This study surveyed 165 genetic counselors within the National Society of Genetic Counselors to assess their current approach to APA. t Tests, analysis of variance, logistic regression, and chi-squared tests were performed on quantitative data, and content analysis was applied to qualitative data. Although most respondents have discussed APA with a patient (88%), there was no consensus on what age cutoff constitutes APA: >40 (N = 53, 37.9%), >45 (N = 61, 43.6%), >50 (N = 24, 17.1%), or >55 (N = 2, 1.4%). Those who discussed APA were more likely to be prenatal counselors, see more patients per week, be board certified, or be familiar with current APA guidelines. Respondents agreed the literature supports the association of APA with deleterious outcomes (mean agreement = 8.2, median = 8 on a 1 = strongly disagree to 10 = strongly agree). Individuals who discussed APA and were board certified had higher agreement. Content analysis confirmed agreement that the literature supports an association between APA and deleterious outcomes (documented in responses from 31.5% of prenatal respondents, 17.8% others) but noted that available testing and screening options for associated conditions are limited (34.4% of prenatal respondents, 17.4% others). Prenatal and non-prenatal respondents reported similar agreement with the statement that APA is associated with deleterious outcomes. However, most non-prenatal respondents were unfamiliar with current guidelines (80%), and presumably as a result, were also less likely to discuss APA with their patients. Our study identified a need to disseminate information regarding APA and current guidelines to genetic counselors, particularly non-prenatal and those with less experience.

Association between paternal age and risk of schizophrenia: a nationwide population-based study

PURPOSE

To study the association between paternal age and schizophrenia in offspring.

METHODS

This report describes a nationwide population-based cohort study from 1997 to 2013. Data from Taiwan's National Health Insurance Research Database were utilized to answer the research question. A total of 17,649 offspring with schizophrenia were selected from 11 million offspring in the general population. Additionally, we established the offspring without schizophrenia as the comparison group by matching the study cohort by age, gender in a 1:4 ratio (n = 70,596).

RESULTS

The median age at first presentation with schizophrenia was 20 years (interquartile range (IQR), 17 to 24). Comparison of the schizophrenia and non-schizophrenia groups indicated that father's age at birth (30.0 (IQR), 27 to 33 vs. 29.0 (IQR), 26 to 32 years), mother's age at birth (26.0 (IQR), 24 to 29 vs. 26.0 (IQR), 23 to 29 years), paternal schizophrenia (2.6% vs. 0.6%), and maternal schizophrenia (4.4% vs. 0.7%) were all significantly greater in the schizophrenia group. In addition, each 5-year increase in father's age increased the odds of being diagnosed with schizophrenia (model 1: aOR = 1.22; 95% CI 1.20, 1.24; model 2: aOR = 1.20; 95% CI 1.18, 1.23). Subgroup analysis showed that each 5-year increase in father's age increased the odds of being diagnosed with schizophrenia in male and female offspring, as well as in offspring of mothers and fathers with or without schizophrenia (aOR = 1.20 to 2.20, all p values < 0.01).

CONCLUSION

This study indicated that advanced paternal age increased the risk of schizophrenia in offspring. Offspring born to fathers older by 5-year increments were at heightened risk of schizophrenia.

Identificação de doenças genéticas na Atenção Primária à Saúde

Problema: Embora individualmente raras, somadas, as doenças genéticas têm prevalência global estimada de 31,5 a 73,0 por 1.000 indivíduos. Além disto, doenças genéticas e defeitos congênitos representam a segunda causa de mortalidade infantil no Brasil. Diante deste cenário, foi instituída a Política Nacional de Atenção Integral às Pessoas com Doenças Raras no Sistema Único de Saúde. Esta política prevê funções específicas para Atenção Primária à Saúde (APS) que incluem diagnóstico precoce e mapeamento de pessoas com ou sob-risco de desenvolver doenças genéticas raras e/ou defeitos congênitos para encaminhamento regulado. Essa experiência objetivou colaborar com o desenvolvimento de métodos para o reconhecimento de indivíduos com ou sob-risco de desenvolver doenças genéticas na APS. Métodos: Através de visitas domiciliares e por meio do preenchimento de uma ficha específica, realizou-se busca ativa de casos de doença genética e/ou defeito congênito em uma amostra probabilística aleatória, representativa de uma Unidade de Saúde da Família de um município brasileiro de porte médio. Resultados: Foram investigados 295 domicílios, totalizando 1.160 indivíduos e 238 casais. A média de filhos por casal foi de 2,7, a frequência de consanguinidade foi 3,8% e de abortamento espontâneo foi 8,7%. Foram identificadas 29 pessoas (2,5%) com doenças congênitas, 11 (0,9%) com deficiências auditivas, 10 (0,9%) com deficiência mental e 6 (0,5%) com déficits visuais importantes. Atraso no desenvolvimento neuropsicomotor foi relatado em 8,8% das crianças e adolescentes. Doze indivíduos (1%) possuíam câncer e 9,6% relataram história familiar positiva para câncer. Conclusão: Os profissionais da APS estão em posição privilegiada para identificar e organizar uma rede de cuidados para indivíduos com doenças genéticas e/ou defeitos congênitos. A utilização sistemática de instrumentos que facilitem o reconhecimento de fatores de risco e de situações suspeitas pode ser uma estratégia útil a ser incorporada pela APS.

The impact of advanced maternal age on pregnancy outcome

Advanced maternal age is becoming an increasingly relevant issue in high-income developed countries. Lower fertility, greater need for assisted reproductive therapy, and an increase in comorbidities, such as hypertension and diabetes, are some of the reasons for the rise in adverse maternal and fetal outcomes. This chapter reviews and summarizes the recent publications on the impact of advanced maternal age on pregnancy outcomes.

Advanced Parental Age at Conception and Sex Affects Mitochondrial DNA Copy Number in Human and Fruit Flies

Aging is a multifactorial trait caused by early as well as late-life circumstances. A society trend that parents deliberately delay having children is of concern to health professionals, for example as advanced parental age at conception increases disease risk profiles in offspring. We here aim to study if advanced parental age at conception affects mitochondrial DNA content, a cross-species biomarker of general health, in adult human twin offspring and in a model organism. We find no deteriorated mitochondrial DNA content at advanced parental age at conception, but human mitochondrial DNA content was higher in females than males, and the difference was twofold higher at advanced maternal age at conception. Similar parental age effects and sex-specific differences in mitochondrial DNA content were found in Drosophila melanogaster. In addition, parental longevity in humans associates with both mitochondrial DNA content and parental age at conception; thus, we carefully propose that a poorer disease risk profile from advanced parental age at conception might be surpassed by superior effects of parental successful late-life reproduction that associate with parental longevity.

Got daddy issues? Fathers impact on perinatal outcomes

Mothers' genetics as well as their environment, behaviors, and social determinants of health are all important factors influencing short and long term childhood outcomes. There is an emerging body of literature investigating the extent to which fathers also contribute to their offspring's future health. We review fathers' impact on short term birth outcomes, longer term health, and neurodevelopment to emphasize the inter-relatedness of individual paternal traits. Factors that are linked to offspring outcomes include paternal demographics, race, stress, marriage and support, mental health, and the baseline health and behaviors of fathers. Several methodologic issues exist in current research such as maternal report of paternal information. Mechanisms proposed regarding paternal effect on progeny health range from genetic to reduction of stress of mothers through support. These are varied, possibly inter-related, and difficult to isolate as a single etiology. Future initiatives need to support fathers to allow them to support their families.

Latest-Late Fertility? Decline and Resurgence of Late Parenthood Across the Low-Fertility Countries

After decades of fertility postponement, we investigate recent changes in late parenthood across low-fertility countries in the light of observations from the past. We use long series of age-specific fertility rates from the Human Fertility Database (1950-2016) for women, and new data covering the period 1990-2016 for men. In 1950, the contribution of births at age 40 and over to female fertility rates ranged from 2.5 to 9 percent, but then fell sharply until the 1980s. From the 1990s, however, the prevalence of late first births increased rapidly, especially so in countries where it was initially lowest. This has produced a late fertility rebound in the last two decades, occurring much faster for women than for men. Comparisons between recent and past extremely late (age 48+) fertility levels confirm that people are now challenging the natural fertility barriers, particularly for a first child.

Sperm Ribosomal DNA Promoter Methylation Levels Are Correlated With Paternal Aging and May Relate With in vitro Fertilization Outcomes

The impact of aging on reproductive outcomes has received considerable critical attention; however, there is much less information available on the effects of paternal age compared to the effects of maternal age. In this study, methylation levels of sperm rDNA promoter regions and Long Interspersed Nucleotide Element 1 (LINE-1) were measured using pyrosequencing and fertilization, day 3 good-quality embryo, pregnancies, and implantation results were assessed. We observed significantly increasing levels of DNA methylation in the sperm rDNA promoter regions with age based on stratifying the samples by age alone (P = 0.0001) and performing linear regression analysis (P < 0.0001). Meanwhile, no statistically significant correlations were observed between global LINE-1 methylation with age. No statistically significant correlations were observed between sperm rDNA promoter methylation levels and either the day 3 good-quality embryo rate or clinical pregnancy rate. In contrast, the correlation between sperm rDNA promoter methylation levels and fertilization (2 pronuclei) rate was nearly significant (P = 0.0707), especially the methylation levels of some individual CpG units (CpG_10, P = 0.0176; CpG_11, P = 0.0438; CpG_14, P = 0.0232) and rDNA promoter methylation levels measured using primerS2 (P = 0.0513). No significant correlation was found between sperm rDNA promoter methylation levels and fertilization rates (2 pronuclei, 1 pronuclei, and 1 polypronuclei). Our results demonstrate that sperm are susceptible to age-associated alterations in methylation levels of rDNA promoter regions, suggesting that sperm rDNA promoter methylation levels can be applied to DNA methylation-based age prediction, and that the aberrant methylation of rDNA promoters may be partially responsible for enhanced disease susceptibility of offspring sired by older fathers. Methylation levels of sperm rDNA promoter regions may correlate with polypronuclei rates of IVF programs.

Risk factors for astigmatic components and internal compensation: the Nanjing Eye Study

Purpose

To determine the risk factors for total astigmatism (TA), anterior corneal astigmatism (ACA), and internal compensation in Chinese preschool children.

Methods

In the population-based Nanjing Eye Study, children were measured for noncycloplegic refractive error and for biometric parameters. Data from questionnaires and measures from right eyes were analyzed for determining risk factors for TA, ACA, and internal compensation from multivariate logistic regression models.

Results

Of 1327 children (66.8 ± 3.4 months, 53.2% male), older age of the child (OR = 0.95 for per month increase; P = 0.03), older paternal age at child birth (OR = 1.04 for per year increase; P = 0.03), paternal astigmatism (OR = 1.89; P = 0.003), maternal astigmatism (OR = 1.73, P = 0.008), and second-hand smoke exposure during pregnancy (OR = 1.64; P = 0.03) were associated with higher risk of TA, while partial breastfeeding (OR = 0.49, P = 0.006) or formula feeding (OR = 0.46, P = 0.003) were associated with lower risk of TA. Larger ratio of axial length to corneal radius (OR = 16.16 for per unit increase; P = 0.001), maternal working during pregnancy (OR = 1.27; P = 0.04), and cesarean delivery (OR = 1.68, P = 0.04) were associated with higher risk of ACA, while formula feeding was associated with lower risk of ACA (OR = 0.57, P = 0.01). Paternal astigmatism (OR = 0.50, P = 0.01) and assisted reproduction (OR = 0.56, P = 0.03) were associated with lower risk of horizontal or vertical internal compensation. More outdoor activity time (OR = 1.15 for per hour increase, P = 0.01) was associated with higher risk of oblique internal compensation while more nighttime sleep on weekends (OR = 0.83 for per hour increase, P = 0.01) was associated with lower risk of oblique internal compensation.

Conclusions

Our study confirmed some previously reported risk factors and identified some novel risk factors for astigmatism including formula feeding for lower risk of both ACA and TA, and older paternal age at child birth for higher risk of TA.

De Novo Mutations Reflect Development and Aging of the Human Germline

Human germline de novo mutations (DNMs) are both a driver of evolution and an important cause of genetic diseases. In the past few years, whole-genome sequencing (WGS) of parent-offspring trios has facilitated the large-scale detection and study of human DNMs, which has led to exciting discoveries. The overarching theme of all of these studies is that the DNMs of an individual are a complex mixture of mutations that arise through different biological processes acting at different times during human development and life.

Predicting Skin Barrier Dysfunction and Atopic Dermatitis in Early Infancy

BACKGROUND

Dry skin is associated with increased transepidermal water loss (TEWL), which has been found to precede atopic dermatitis (AD) in childhood.

OBJECTIVE

We aimed to identify parental, prenatal, and perinatal predictive factors of dry skin, high TEWL, and AD at 3 months of age, and to determine if dry skin or high TEWL at 3 months can predict AD at 6 months.

METHODS

From the Preventing Atopic Dermatitis and Allergies in children prospective birth cohort study, we included 1150 mother-child pairs. Dry skin, TEWL, and eczema were assessed at 3- and 6-month investigations. Eczema, used as a proxy for AD, was defined as the presence of eczematous lesions, excluding differential diagnoses to AD. High TEWL was defined as TEWL >90th percentile, equaling 11.3 g/m²/h. Potential predictive factors were recorded from electronic questionnaires at 18- and 34-week pregnancy and obstetric charts.

RESULTS

Significant predictive factors (P < .05) for dry skin at 3 months were delivery >38 gestational weeks and paternal age >37 years; for high TEWL, male sex, birth during winter season, and maternal allergic disease; and for eczema, elective caesarean section, multiparity, and maternal allergic diseases. Dry skin without eczema at 3 months was predictive for eczema at 6 months (adjusted odds ratio: 1.92, 95% confidence interval: 1.21-3.05; P = .005), whereas high TEWL at 3 months was not.

CONCLUSION

In early infancy, distinct parental- and pregnancy-related factors were predictive for dry skin, high TEWL, and AD. Dry skin at 3 months of age was predictive for AD 3 months later.

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.

Aging and the Male Reproductive System

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