Impact of Paternal Age at Conception on Human Health

Association of advanced paternal age with lung function at school age

BACKGROUND

Epidemiological studies suggest that advanced paternal age impact offspring health, but its impact on respiratory health is unclear. This study aimed to investigate the association of paternal age with lung function and fraction of exhaled nitric oxide (FeNO) in children.

METHODS

We analyzed data from 1330 single-born children (576 girls, 43.3%; mean age, 6.4 years), who participated in the Longitudinal Investigation of Global Health in Taiwanese Schoolchildren (LIGHTS) cohort and received measurements of lung function and FeNO at 6-year follow-up visits. Covariate-adjusted regression analyses were applied.

RESULTS

Every 5-year increase in paternal age at birth was associated with 0.51% decrease in FEV1/FVC ratio (95% CI - 0.86 to - 0.15; p = 0.005) and 19.86 mL/s decrease in FEF75 (95% CI: - 34.07 to - 5.65; p = 0.006). Stratified analyses revealed that increasing paternal age at birth was associated with decreasing FEV1/FVC ratio and FEF75 only among children with prenatal exposure to environmental tobacco smoke (ETS) or not being breastfed. Sensitivity analyses using paternal age as a categorical variable found decreasing FEV1/FVC ratio and FEF75 in the groups of paternal age 35-39 and ≥ 40 years. There was no association of paternal age at birth with FeNO.

CONCLUSION

Our findings provide novel evidence linking advanced paternal age at birth with decreasing lung function in children at school age. Children with prenatal exposure to ETS or not being breastfed are more vulnerable to the adverse effect of advanced paternal age on childhood lung function. Further studies are warranted to confirm this novel adverse effect of advanced paternal age.

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.

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.

Like Father, Like Child? Paternal Age at Birth and Offspring’s Facial Asymmetry and Distinctiveness

Paternal age at birth, a potential proxy of mutation load transmitted to the offspring, has previously been related to the offspring’s health, biological condition and reproductive potential. As higher facial asymmetry and distinctiveness serve as putative markers of the lower genetic quality of an individual, we hypothesize that more advanced paternal age at birth will be related to children’s higher levels of facial asymmetry and distinctiveness. To the best of our knowledge, this is the first study evaluating the link between paternal age at birth and facial asymmetry in offspring. Based on archived photographs of 159 children born within 47 Polish families, we have conducted facial geometric morphometric measurements and calculated the levels of facial asymmetry and distinctiveness. The relationship between paternal age at birth and the offspring’s facial features was explored with the use of Bayesian Linear Mixed-effects Models, controlling for sex, age and birth order of the offspring, and maternal age at child’s birth. No associations between paternal age at birth and facial asymmetry or distinctiveness in children were found. The lack of such a relationship might be a result of the potentially insufficient influence of newly accumulated paternal mutations affecting the offspring’s phenotype or higher importance of maternal (prenatal) and postnatal environments in shaping facial features.

Sperm mosaicism: implications for genomic diversity and disease

While sperm mosaicism has few consequences for men, the offspring and future generations are unwitting recipients of gonadal cell mutations, often yielding severe disease. Recent studies, fueled by emergent technologies, show that sperm mosaicism is a common source of de novo mutations (DNMs) that underlie severe pediatric disease as well as human genetic diversity. Sperm mosaicism can be divided into three types: Type I arises during sperm meiosis and is non-age dependent; Type II arises in spermatogonia and increases as men age; and Type III arises during paternal embryogenesis, spreads throughout the body, and contributes stably to sperm throughout life. Where Types I and II confer little risk of recurrence, Type III may confer identifiable risk to future offspring. These mutations are likely to be the single largest contributor to human genetic diversity. New sequencing approaches may leverage this framework to evaluate and reduce disease risk for future generations.

Male age interferes with embryo growth in IVF treatment

STUDY QUESTION

Does male age affect embryo growth or quality in couples undergoing IVF treatment?

SUMMARY ANSWER

Advanced paternal age (APA) is negatively associated with the chance of an optimal eight-cell embryo on the third day of development.

WHAT IS KNOWN ALREADY

Literature shows that APA is associated with decreased sperm quality and fecundity. However, the effect of male age on embryo growth in an IVF setting remains inconclusive. Literature concerning male influences on IVF success is scarce and approaches used to analyse embryo outcomes differ by study.

STUDY DESIGN, SIZE, DURATION

This study was part of the longitudinal Epigenetic Legacy of Paternal Obesity (ELPO) study for which fathers and mothers were followed from pre-pregnancy until the birth of their child. Couples were recruited from April 2015 to September 2017. A total of 1057 embryos from 87 couples were studied.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Dutch-speaking couples planning to undergo an IVF treatment were recruited at the Leuven University Fertility Center in Flanders, Belgium. Anthropometrics were documented and compared to the general Flemish population. Semen characteristics, pregnancy rates and the following embryo characteristics were recorded: number of blastomeres, symmetry and percentage fragmentation. Statistical modelling was applied taking into account correlation of within-cycle outcomes and use of multiple cycles per couple.

MAIN RESULTS AND THE ROLE OF CHANCE

We observed a significant inverse association between APA and a key determinant for scoring of embryo quality: older men were less likely to produce an embryo of eight blastomeres at Day 3, compared to younger fathers; odds ratio for the effect of 1 year equals 0.960 (95% CI: 0.930-0.991; P = 0.011). Our finding remained significant after adjusting for female age and male and female BMI. Degree of fragmentation and symmetry were not significantly related to male age.

LIMITATIONS, REASONS FOR CAUTION

Because of the study's small sample size and its monocentric nature, a larger study is warranted to confirm our results. In addition, distribution of BMI and level of education were not representative of the general Flemish population. Although we corrected for BMI status, we do not exclude that obesity may be one of the determinants of infertility in our study population. Furthermore, it is known from other European countries that a higher education eases access to fertility treatment. Hence, caution should be taken when interpreting our findings from a fertility setting to the general population.

WIDER IMPLICATIONS OF THE FINDINGS

We suggest a heightened need for future research into male age and its potential effects on embryo growth, embryo quality and ART outcomes. Clinical decision-making and preventative public health programmes would benefit from a better understanding of the role of men, carried forward by the Paternal Origins of Health and Disease (POHaD) paradigm. We hope the current finding will encourage others to examine the role of the sperm epigenome in embryo development according to paternal age.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by a research grant from KU Leuven University (OT/14/109). The authors declare no competing financial, professional or personal interests.

TRIAL REGISTRATION NUMBER

KU Leuven S57378 (ML11309), B322201523225.

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.

Abnormal Levels of Metal Micronutrients and Autism Spectrum Disorder: A Perspective Review

The aim of the present review is to summarize the prevalence of abnormal levels of various metal micronutrients including copper (Cu), iron (Fe), magnesium (Mg), zinc (Zn), and selenium (Se) in Autism Spectrum Disorder (ASD) using hair, nail and serum samples. A correlation of selected abnormal metal ions with known neurodevelopmental processes using Gene Ontology (GO) term was also conducted. Data included in this review are derived from ASD clinical studies performed globally. Metal ion disparity data is also analyzed and discussed based on gender (Male/Female) to establish any gender dependent correlation. Finally, a rational perspective and possible path to better understand the role of metal micronutrients in ASD is suggested.

Placental and Cord Blood Telomere Length in Relation to Maternal Nutritional Status

BACKGROUND

The uterine environment may be important for the chromosomal telomere length (TL) at birth, which, in turn, influences disease susceptibility throughout life. However, little is known about the importance of specific nutritional factors.

OBJECTIVES

We assessed the impact of multiple maternal nutritional factors on TL in placenta and cord blood.

METHODS

In a population-based mother-child cohort in northwestern Argentina, we measured maternal weight, BMI, body fat percentage (BFP), and several nutrients [selenium, magnesium, calcium, zinc, manganese, iodine, vitamin B-12, folate, 25-hydroxycholecalciferol (25(OH)D3)], hemoglobin, and homocysteine in maternal whole blood, serum, plasma, or urine during pregnancy (mean gestational week 27). We measured the relative TL (rTL) in placenta (n = 99) and cord blood (n = 98) at delivery by real-time PCR. Associations were evaluated by multivariable-adjusted linear regression.

RESULTS

The women's prepregnancy BMI (kg/m2; mean ± SD: 23.7 ± 4.1), body weight (55.4 ± 9.9 kg), and BFP (29.9 ± 5.5%), but not height (153 ± 5.3 cm), were inversely associated with placental rTL (P < 0.01 for all), with ∼0.5 SD shorter rTL for an IQR increase in prepregnancy body weight, BMI, or BFP. Also, impedance-based BFP, but not lean body mass, in the third trimester was associated with shorter placental rTL. In addition, serum vitamin B-12 (232 ± 96 pmol/L) in pregnancy (P = 0.038), but not folate or homocysteine, was associated with shorter placental rTL (0.2 SD for an IQR increase). In contrast, plasma 25(OH)D3 (46 ± 15 nmol/L) was positively associated with placental rTL (P < 0.01), which increased by 0.4 SD for an IQR increase in 25(OH)D3. No clear associations of the studied maternal nutritional factors were found with cord blood rTL.

CONCLUSIONS

Maternal BMI, BFP, and vitamin B-12 were inversely associated, whereas 25(OH)D3 was positively associated, with placental TL. No association was observed with cord blood TL. Future studies should elucidate the role of placental TL for child health.

Epidemiology of craniosynostosis in Norway

OBJECTIVE

The authors present population-based epidemiological data for craniosynostosis regarding incidence, age at diagnosis, sex differences, and frequency of syndromic and familial cases.

METHODS

The prospective registry of the Norwegian National Unit for Craniofacial Surgery was used to retrieve data on all individuals with craniosynostosis treated between 2003 and 2017. The cohort was divided into three 5-year groups based on year of birth: 2003-2007, 2008-2012, and 2013-2017.

RESULTS

The authors identified 386 individuals with craniosynostosis. Of these, 328 (85%) consented to be registered with further information. The incidence increased significantly during the study period and was 5.5 per 10,000 live births (1/1800) in the last 5-year period. The increase was seen almost exclusively in the nonsyndromic group. Syndromic craniosynostosis accounted for 27% of the cases, and the incidence remained stable throughout the three 5-year periods. Both syndromic and nonsyndromic craniosynostosis were highly suture specific. There was a male preponderance (male/female ratio 2:1), and males accounted for 75% of the individuals with midline synostosis. Overall, 9.5% were index individuals in families with more than one affected member; of these, 73% were nonsyndromic cases.

CONCLUSIONS

The incidence of craniosynostosis increased during the study period, and the observed incidence is among the highest reported. The authors attribute this to increasing awareness among healthcare professionals. The number of syndromic cases was high, likely due to a broader definition compared to the majority of earlier reports. The study revealed a high number of familial cases in both syndromic and nonsyndromic craniosynostosis, thus highlighting the importance of genetics as an underlying cause of craniosynostosis.

Associations of sperm telomere length with semen parameters, clinical outcomes and lifestyle factors in human normozoospermic samples

BACKGROUND

Many studies have demonstrated that lifestyle factors can affect sperm quality and fertility. Sperm telomere length (STL) has been reported as potential biomarker or sperm quality. However, no studies have investigated how lifestyle factors can affect STL and associated clinical outcomes.

OBJECTIVES

The purpose of this manuscript is to investigate any association between STL with lifestyle factors, semen parameters and clinical outcomes.

MATERIALS AND METHODS

Sperm telomere length was measured using real-time PCR in normozoospermic male partners (n = 66) of couples undergoing ART treatment. Each participant also completed a detailed questionnaire about general lifestyle. Linear regression univariate analysis and ANCOVA were performed to respectively determine correlations between STL and study parameters or identify statistically significant differences in STL while controlling for age, BMI and other factors.

RESULTS

Using a linear regression model, STL is positively correlated with in vitro fertilization success (n = 65, r = 0.37, P = .004) but not with embryo cleavage rates and post-implantation clinical outcomes including gestational age-adjusted birth weight. No associations were observed between STL and sperm count, concentration or progressive motility. We further found that STL did not associate age, BMI, health or lifestyle factors.

DISCUSSION

In somatic cells, the rate of telomere shortening is influenced by a number of lifestyle factors such as smoking, diet and occupation. However, little is known about how lifestyle factors affect STL and subsequently reproductive outcome. Out data suggest that STL might have an important role mechanistically for fertilization rate regardless of sperm parameters and lifestyle factors.

CONCLUSION

The results of this study demonstrate that STL is associated with in vitro fertilization rates, but not with semen parameters nor lifestyle factors. Further investigations are warranted to identify the potential variation of STL overtime to clarify its significance as a potential biomarker in ART.

The present crisis in male reproductive health: an urgent need for a political, social, and research roadmap

BACKGROUND

There is a global crisis in male reproductive health. Evidence comes from globally declining sperm counts and increasing male reproductive system abnormalities, such as cryptorchidism, germ cell tumors, and onset of puberty. Male factor infertility occurs in ~40% of couples experiencing infertility. Data demonstrate an association between male infertility and overall health. Associated significant health conditions include diabetes mellitus, metabolic disorders, and cardiovascular disease. Adding to the complexity is that men typically do not seek health care unless there is acute medical need or, as in the case of the infertile couple, the male goes for a reproductive examination and semen analysis. However, 25% of the time a reproductive health examination does not occur. Couples are increasingly utilizing IVF at more advanced ages, and advanced paternal age is associated with increased risk for (i) adverse perinatal outcomes for both offspring and mother; (ii) early child mortality, cancer, and mental health issues. In addition to age, paternal lifestyle factors, such as obesity and smoking, impact not only the male fertility but also the offspring wellness.

OBJECTIVES

The purpose of this paper was (i) to spotlight emerging and concerning data on male reproductive health, the relationship(s) between male reproductive and somatic health, and the heritable conditions father can pass to offspring, and (ii) to present a strategic roadmap with the goals of increasing (a) the awareness of men and society on the aforementioned, (b) the participation of men in healthcare seeking, and (c) advocacy to invigorate policy and funding agencies to support increased research into male reproductive biology.

CONCLUSIONS

The Male Reproductive Health Initiative (MRHI) is a newly established and rapidly growing global consortium of key opinion leaders in research, medicine, funding and policy agencies, and patient support groups that are moving forward the significant task of accomplishing the goals of the strategic roadmap.