Paternal contributors in recurrent pregnancy loss: Cues from comparative proteome profiling of seminal extracellular vesicles.

Recent evidence entail paternal factors as plausible contributors in spontaneous recurrent pregnancy loss (RPL). Seminal extracellular vesicles secreted from cells of male reproductive tract carry regulatory proteins and RNAs. They are proposed to regulate sperm maturation and function while their fusion to endometrial stromal cells helps in decidualization. Nevertheless, the mechanism(s) involved in these processes are poorly understood. This study aims at elucidating the molecular basis of paternal contribution by comparative proteomics (label-free LC-MS/MS) of isolated seminal extracellular vesicles from fertile men and partners of patients with RPL (n = 21 per group). Bioinformatics analysis revealed the identified differentially expressed proteins to be involved in DNA replication, recombination and repair, gene expression, cellular assembly and organization, cell death, and survival. Major disease pathways affected were identified as developmental, hereditary, and immunological disorders. Of the three identified hub genes regulating the above disease pathways, two (HNRNPC and HNRNPU) are overexpressed while RUVBL1 is underexpressed along with over expression of HIST1H1C, DDX1, surmising defective chromatin packaging, and histone removal in spermatozoa resulting in improper expression in paternal genes thereby leading to abnormal embryo development. Besides, alteration in GSTP1 expression points oxidative predominance in RPL group. Differential expression of C3, C4a/C4b, CFB, and GDF 15 may be involved in altered maternal immune response to paternal antigens resulting in impaired decidualization.

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

STUDY QUESTION: Is there an association between advanced paternal age and congenital heart defects (CHD)? SUMMARY ANSWER: Advanced paternal age is associated with a 16% increase in the overall odds of CHD. WHAT IS KNOWN ALREADY: CHD are the most common congenital malformations. Several risk factors for CHD have been identified in the literature, but the association between advanced paternal age and CHD remains unclear. STUDY DESIGN, SIZE, DURATION: We conducted a systematic literature search on MEDLINE and EMBASE (1960-2019) to identify studies assessing the association between advanced paternal age (≥35 years) and the risk of CHD, unrestrictive of language or sample size. We used a combination of Medical Subject Headings (MeSH) terms and free text words such as 'paternal age', 'paternal factors', 'father's age', 'parental age', 'heart', 'cardiac', 'cardiovascular', 'abnormalities, congenital', 'birth defects', 'congenital malformations' and 'congenital abnormalities'. PARTICIPANTS/MATERIALS, SETTING, METHODS: We included observational studies aiming at assessing the association between paternal age and CHD. The included population could be live births, fetal deaths and terminations of pregnancy for fetal anomaly. To be included, studies had to provide either odds ratios (OR) with their 95% confidence interval (CI) or sufficient information to recalculate ORs with 95% CIs per paternal age category. We excluded studies if they had no comparative group and if they were reviews or case reports. Two independent reviewers selected the studies, extracted the data and assessed risk of bias using a modified Newcastle-Ottawa Scale. We used random-effects meta-analysis to produce summary estimates of crude OR. Associations were also tested in subgroups. MAIN RESULTS AND THE ROLE OF CHANCE: Of 191 studies identified, we included nine studies in the meta-analysis (9 917 011 participants, including 34 447 CHD), including four population-based studies. Five studies were judged at low risk of bias. Only one population-based study specifically investigated isolated CHD. The risk of CHD was higher with advanced paternal age (summary OR 1.16, 95% CI, 1.07-1.25). Effect sizes were stable in population-based studies and in those with low risk of bias. LIMITATIONS AND REASONS FOR CAUTION: The available evidence did not allow to assess (i) the risk of isolated CHD in population-based studies, (ii) the association between paternal age and the risk for specific CHD and (iii) the association between paternal age and CHD after adjustment for other risk factors, such as maternal age. WIDER IMPLICATIONS OF THE FINDINGS: Our findings suggest that advanced paternal age may be a risk factor for CHD. However, because the association is modest in magnitude, its usefulness as a criterion for targeted screening for CHD seems limited. STUDY FUNDING/COMPETING INTEREST(S): None. PROSPERO REGISTRATION NUMBER: CRD42019135061.

Quantitative proteomics decodes clusterin as a critical regulator of paternal factors responsible for impaired compensatory metabolic reprogramming in recurrent pregnancy loss.

Recurrent pregnancy loss (RPL) is a perplexing problem experienced with two or more consecutive miscarriages wherein the cause remains unexplained in >50% of cases. However, despite several evidences of involvement of paternal factors on early embryogenesis and placental development, its contribution towards RPL has been largely unexplored. There is augmented lipid peroxidation, protein carbonylation, thionylation and enhanced histone retention in spermatozoa of RPL patients. Differentially expressed proteins in the spermatozoa of RPL patients may contribute towards aberrant embryo development and pregnancy loss. The present study comprised of male partners of RPL patients (n = 16) with the absence of any female factor abnormality and age-matched fertile healthy donors (n = 20). Pooled sperm samples from each group were subjected to high-throughput liquid chromatography-tandem mass spectrophotometry (LC-MS/MS) and subsequent bioinformatic analysis that identifies key proteins to be differentially expressed (DEPs). A total of 23 DEPs were identified with ≥2.0 fold change were considered to be significant. A key finding of the study was clusterin (CLUS), a predominant oxidative stress protein that takes part in an array of pre- and post-fertilisation molecular processes, found to be underexpressed as it was confirmed by Western blot analysis. This pilot study supports contributions of paternal oxidative predominance in RPL and encourages further investigation.

Paternal factors contributing to embryo quality.

PURPOSE: Advancing maternal and paternal age leads to a decrease in fertility, and hence, many infertile couples opt for assisted reproductive technologies [ART] to achieve biological parenthood. One of the key determinants of achieving a live outcome of ART, embryo quality, depends on both the quality of the oocyte and sperm that have created the embryo. Several studies have explored the effect of oocyte parameters on embryo quality, but the effects of sperm quality on the embryo have not been comprehensively evaluated. METHOD: In this review, we assess the effect of various genetic factors of paternal origin on the quality and development of the embryo. RESULTS: The effects of sperm aneuploidy, sperm chromatin structure, deoxyribonucleic acid [DNA] fragmentation, role of protamines and histones, sperm epigenetic profile, and Y chromosome microdeletions were explored and found to negatively affect embryo quality. CONCLUSION: We propose that careful assessment of spermatozoal parameters is essential to achieve embryo development and a healthy live birth. However, the heterogeneity in test results and the different approaches of assessing a single sperm parameter highlight the need for more research and the development of standardized protocols to assess the role of sperm factors affecting embryo quality.

Association of missing paternal demographics on infant birth certificates with perinatal risk factors for childhood obesity.

BACKGROUND: The role of fathers in the development of obesity in their offspring remains poorly understood. We evaluated associations of missing paternal demographic information on birth certificates with perinatal risk factors for childhood obesity. METHODS: Data were from the Linked CENTURY Study, a database linking birth certificate and well-child visit data for 200,258 Massachusetts children from 1980-2008. We categorized participants based on the availability of paternal age, education, or race/ethnicity and maternal marital status on the birth certificate: (1) pregnancies missing paternal data; (2) pregnancies involving unmarried women with paternal data; and (3) pregnancies involving married women with paternal data. Using linear and logistic regression, we compared differences in smoking during pregnancy, gestational diabetes, birthweight, breastfeeding initiation, and ever recording a weight for length (WFL) ≥ the 95th percentile or crossing upwards ≥2 WFL percentiles between 0-24 months among the study groups. RESULTS: 11,989 (6.0 %) birth certificates were missing paternal data; 31,323 (15.6 %) mothers were unmarried. In adjusted analyses, missing paternal data was associated with lower birthweight (ß -0.07 kg; 95 % CI: -0.08, -0.05), smoking during pregnancy (AOR 4.40; 95 % CI: 3.97, 4.87), non-initiation of breastfeeding (AOR 0.39; 95 % CI: 0.36, 0.42), and with ever having a WFL ≥ 95th percentile (AOR 1.10; 95 % CI: 1.01, 1.20). Similar associations were noted for pregnancies involving unmarried women with paternal data, but differences were less pronounced. CONCLUSIONS: Missing paternal data on the birth certificate is associated with perinatal risk factors for childhood obesity. Efforts to understand and reduce obesity risk factors in early life may need to consider paternal factors.

Transgenerational effects of paternal exposures: the role of germline de novo mutations.

Germline de novo mutations (DNMs) refer to spontaneous mutations arising during gametogenesis, resulting in genetic changes within germ cells that are subsequently transmitted to the next generation. While the impact of maternal exposures on germline DNMs has been extensively studied, more recent studies have begun to highlight the increasing importance of the effects of paternal factors. In this review, we have summarized the existing literature on how various exposures experienced by fathers affect the germline DNM burden in their spermatozoa, as well as their consequences for semen analysis parameters, pregnancy outcomes, and offspring health. A growing body of literature supports the conclusion that advanced paternal age (APA) correlates with a higher germline DNM rate in offspring. Furthermore, lifestyle choices, environmental toxins, assisted reproductive techniques (ART), and chemotherapy are associated with the accumulation of paternal DNMs in spermatozoa, with deleterious consequences for pregnancy outcomes and offspring health. Ultimately, our review highlights the clear importance of the germline DNM mode of inheritance, and the current understanding of how this is affected by various paternal factors. In addition, we explore conflicting reports or gaps of knowledge that should be addressed in future research.

Childhood cardiometabolic risk factors associated with the perinatal environment of the maternal-paternal-child triad.

INTRODUCTION: Clustering of cardiometabolic risk factors in childhood significantly increases the risk of atherosclerotic cardiovascular disease later in life. Identification of modifiable parental factors that contribute to offspring cardiometabolic health is critical for the prevention of disease. The objective was to identify factors associated with child cardiometabolic risk factors at age 5 years. METHODS: Triads from a longitudinal cohort were recalled at 5 years (n = 68). Dietary intake, anthropometrics, physical activity and serum-based risk factors were collected. Best subset selection, linear and logistic regressions were used to identify triad variables associated with increased risk of cardiometabolic risk factor clustering at age 5 years. RESULTS: In this cohort, best subset modelling revealed that increased paternal fat mass, serum low-density lipoproteins and triglycerides, maternal dietary added sugar and being female were associated with increased odds of offspring having two or more cardiometabolic risk factors at age 5 years. CONCLUSIONS: Dietary and exercise interventions prior to conception targeting paternal adiposity and dyslipidaemia as well as maternal dietary habits could decrease children's cardiometabolic risk in later life.

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.

Proteomic Signatures in Spermatozoa Reveal the Role of Paternal Factors in Recurrent Pregnancy Loss.

PURPOSE: To identify the paternal factors responsible for aberrant embryo development leading to loss of foetus in recurrent pregnancy loss (RPL) through proteomic analysis of ejaculated spermatozoa. MATERIALS AND METHODS: This prospective study consisted of male partners of RPL patients (n=16) experienced with two or more consecutive unexplained miscarriages and with no female factor abnormality as revealed by gynaecologic investigation including karyotyping and age matched fertile healthy volunteers (n=20). All samples were collected during 2013 to 2015 after getting institutional ethical approval and written consent from the participants. Seminal ejaculates were collected by masturbation after 2 to 3 days of sexual abstinence and analyzed according to World Health Organization 5th criteria 2010. Two-dimensional difference gel electrophoresis followed by mass spectrophotometric analysis was used to identify differentially expressed proteins (DEPs). Western blotting was used for validation of the key proteins. RESULTS: The data identified 36 protein spots to be differentially expressed by more than 2-fold change with p<0.05 considered as significant. Matrix-assisted laser desorption/ionization time of flight/mass spectrometry identified GPx4, JIP4, ZN248 to be overexpressed while HSPA2, GSTM5, TF3C1, CC74A was underexpressed in RPL group. Western blot analysis confirmed the differential expression of key redox associated proteins GPx4 and HSPA2 in the RPL group. Functional analysis revealed the involvement of key biological processes that includes spermatogenesis, response to oxidative stress, protein folding and metabolic process. CONCLUSIONS: The present study provides a snapshot of the altered protein expression levels consistent with the potential involvement of the sperm chromatin landscape in early embryonic development.

Maternal Exposure to Childhood Abuse is Associated with Mate Selection: Implications for Autism in Offspring.

Maternal experience of childhood abuse has been associated with offspring autism. To explore whether familial tendency towards autistic traits-presumably related to genetic predisposition-accounts for this association, we examined whether women who experienced childhood abuse were more likely to select mates with high levels of autistic traits, and whether parental autistic traits accounted for the association of maternal abuse and offspring autism in 209 autism cases and 833 controls. Maternal childhood abuse was strongly associated with high paternal autistic traits (severe abuse, OR = 3.98, 95% CI = 1.26, 8.31). Maternal and paternal autistic traits accounted for 21% of the association between maternal abuse and offspring autism. These results provide evidence that childhood abuse affects mate selection, with implications for offspring health.