Advanced paternal age is associated with an increased risk of spontaneous miscarriage: a systematic review and meta-analysis

Increased paternal age adversely affects live birth rates in oocyte recipient cycles

This retrospective cohort study was conducted in a single center to investigate the influence of paternal age on oocyte recipient cycles. 320 IVF/ICSI oocyte recipient cycles resulting in embryo transfers between 01/2015- 06/2022 and meeting the inclusion criteria: donors ≤35 years, endometrial thickness 6mm and normal endometrial cavity were analyzed. Donor or surgically retrieved sperm or PGT-A cycles were excluded. Paternal and recipient ages were grouped according to previous literature for comparability. Primary outcome was live birth rate, and secondary outcomes were clinical pregnancy and miscarriage rates. The median recipient, paternal and donor ages were 42 (IQR: 19-50), 43 (IQR: 38-46) and 26 years (IQR: 23-29). 55.6% [N=178] of the cycles were fresh and 44.3% [N=142] were frozen embryo transfers. Univariate and multivariate logistic regression, adjusted for semen WHO criteria, recipient age, IVF/ICSI and fresh/frozen cycles highlighted reduced odds of live birth by 79%, OR 0.21 [95%CI 0.11 to 0.38]; P<0.0001, clinical pregnancy by 58%, OR 0.42 [95%CI 0.31 to 0.89]; P<0.0001 and increased odds of miscarriage by 108%, OR 2.08 [95%CI 1.91 to 3.01]; P<0.0001 in those of paternal age 51 years compared to fathers ≤35 years. Our study identifies the negative impact of advanced paternal age.

Redox-Driven Epigenetic Modifications in Sperm: Unraveling Paternal Influences on Embryo Development and Transgenerational Health

Male-factor infertility accounts for nearly half of all infertility cases, and mounting evidence points to oxidative stress as a pivotal driver of sperm dysfunction, genetic instability, and epigenetic dysregulation. In particular, the oxidative DNA lesion 8-hydroxy-2'-deoxyguanosine (8-OHdG) has emerged as a central mediator at the interface of DNA damage and epigenetic regulation. We discuss how this lesion can disrupt key epigenetic mechanisms such as DNA methylation, histone modifications, and small non-coding RNAs, thereby influencing fertilization outcomes, embryo development, and offspring health. We propose that the interplay between oxidative DNA damage and epigenetic reprogramming is further exacerbated by aging in both the paternal and maternal germlines, creating a "perfect storm" that increases the risk of heritable (epi)mutations. The consequences of unresolved oxidative lesions can thus persist beyond fertilization, contributing to transgenerational health risks. Finally, we explore the promise and potential pitfalls of antioxidant therapy as a strategy to mitigate sperm oxidative damage. While antioxidant supplementation may hold significant therapeutic value for men with subfertility experiencing elevated oxidative stress, a careful, personalized approach is essential to avoid reductive stress and unintended epigenetic disruptions. Recognizing the dual role of oxidative stress in shaping both the genome and the epigenome underscores the need for integrating redox biology into reproductive medicine, with the aim of improving fertility treatments and safeguarding the health of future generations.

High risk of low birth weight in couples with advanced paternal age in in vitro fertilization treatment

BACKGROUND

With the development of socio-economic conditions and a shift in attitudes towards fertility, there has been a gradual increase in delayed childbearing since the 2000s. Age plays a significant role in the decline of fertility. However, we know very little about the association of paternal age with reproductive outcomes.

OBJECTIVES

To investigate the correlation between advanced paternal age and semen quality, embryo quality, pregnancy, and neonatal outcomes in IVF cycles.

MATERIALS AND METHODS

In this study, after excluding female partners aged ≥35 years, we analyzed data from 761 infertile couples who underwent in vitro fertilization cycles at the First Affiliated Hospital of USTC between June 2020 and March 2023. Cases were classified into three groups according to the age of the male: <35 years (530 infertile couples), 35 years ≤ paternal age <40 years (125 infertile couples), and ≥40 years (106 infertile couples). Then, we compared the general clinical data arising from in vitro fertilization cycles between the three groups, including semen parameters, embryonic parameters, and pregnancy and neonatal birth outcomes.

RESULTS

Data analysis showed that the duration of infertility and the incidence of secondary infertility were significantly higher in paternal age ≥35 years groups than those aged <35 years (all p < 0.05). We also observed a significant difference between ≥40 years and <35 years groups in terms of the normal fertilization rate, high-quality embryo rate, clinical pregnancy rate, miscarriage rate, live birth rate, Apgar scores, and the low birth weight neonatal rate (all p < 0.05). The group with paternal age ≥40 years showed statistically significant differences in terms of clinical pregnancy rate, miscarriage rate, live birth rate, and low birth weight on multivariable logistic regression (all p < 0.05).

CONCLUSION

The results of our study indicate that advanced paternal age (≥40 years) has a significant impact on the embryo quality, pregnancy outcome, and neonatal outcome. Paternal age over 40 years is a risk for in vitro fertilization success rate.

Primary infertile couples share more HLA alleles than expected by chance

OBJECTIVE

To examine whether the rate of HLA similarity among 609 primarily infertile couples is higher than would be expected by chance.

DESIGN

Clinical Trial.

SUBJECTS

609 primary infertile couples (mean age women: 34.35 years, men: 37.59 years) were recruited before undergoing IVF or ICSI therapy. Couples with former pregnancies, tubal factor, azoospermia or donor therapies were excluded.

INTERVENTION

For each of the partners, exons encoding the corresponding antigen recognition sites of HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1 were sequenced by using next-generation sequencing. HLA similarity between partners was determined based on the probability of homozygous offspring and the observed probability of heterozygous offspring in the sample of primary infertile couples was comparted to the probability for random pairing using bootstrapping.

MAIN OUTCOME MEASURES

HLA similarity of infertile couples compared to randomly assigned couples.

RESULTS

In each of the loci, infertile pairs shared more alleles than expected by chance. This result was significant for all HLA class 2 loci (-DRB1, -DQB1, -DPB1), as well as for the HLA class I locus -C, while HLA-A and -B showed a nonsignificant trend towards higher similarity.

CONCLUSION

These data suggest that HLA similarity between couples relates to primary infertility.

Paternal Inflammatory Bowel Disease and the Risk of Pregnancy Loss

BACKGROUND

Only about 30% of conceptions end in live births, yet there are little data on paternal causes of pregnancy loss. Men with inflammatory bowel disease may have multiple disease-related issues that may affect fertility. We aimed to examine pregnancy outcomes in women undergoing assisted reproduction whose male partners had Crohn's disease or ulcerative colitis.

METHODS

This nationwide study included all embryo transfers registered in the Danish Assisted Reproduction Registry from January 2, 2006, to September 3, 2019. The exposed cohort included embryo transfers from couples in which the male partners had Crohn's disease or ulcerative colitis. The unexposed cohort included embryo transfers in which male partners did not have inflammatory bowel disease.

RESULTS

For fathers with ulcerative colitis, the adjusted odds ratio for a positive biochemical pregnancy (positive human chorionic gonadotropin) was 1.14 (95% confidence interval [CI], 0.92-1.42), for a clinical pregnancy (positive vaginal ultrasonography at 7-8 weeks) was 0.91 (95% CI, 0.59-1.40), and for a live birth was 0.99 (95% CI, 0.71-1.60). For fathers with Crohn's disease, the adjusted odds ratio for a biochemical pregnancy was 0.83 (95% CI, 0.63-1.09), for a clinical pregnancy was 0.58 (95% CI, 0.34-0.97), and for a live birth was 0.88 (95% CI, 0.51-1.55).

CONCLUSIONS

These findings may indicate that partners of men with Crohn's disease may have an increased risk of early pregnancy loss. Future studies should confirm these results and examine the impact of paternal medications, paternal disease activity, and other factors associated with chronic inflammatory bowel disease.

Single-cell transcriptomic atlas of the human testis across the reproductive lifespan

Testicular aging is associated with declining reproductive health, but the molecular mechanisms are unclear. Here we generate a dataset of 214,369 single-cell transcriptomes from testicular cells of 35 individuals aged 21-69, offering a resource for studying testicular aging and physiology. Machine learning analysis reveals a stronger aging response in somatic cells compared to germ cells. Two waves of aging-related changes are identified: the first in peritubular cells of donors in their 30s, marked by increased basement membrane thickness, indicating a priming state for aging. In their 50s, testicular cells exhibit functional changes, including altered steroid metabolism in Leydig cells and immune responses in macrophages. Further analyses reveal the impact of body mass index on spermatogenic capacity as age progresses, particularly after age 45. Altogether, our findings illuminate molecular alterations during testis aging and their relationship with body mass index, providing a foundation for future research and offering potential diagnostic markers and therapeutic targets.

Abnormal sperm tails correlate with the sperm DNA fragmentation index, irrespective of progressive motility, according to an analysis of 5125 semen reports

PURPOSE

Sperm progressive motility (PR) is correlated with the sperm DNA fragmentation index (SDF). Moreover, abnormalities in sperm tails are closely associated with the quality of sperm PR. However, the correlation of abnormal sperm tails with the SDF remains unknown.

METHODS

Routine semen examination was performed according to the World Health Organization guidelines with a computer-assisted semen analysis system. SDF analysis was conducted via the sperm chromatin structure assay method. Spearman correlation was used to test the correlation of the SDF with age and conventional semen parameters. The relationship between the SDF and abnormal tails was explored by binary logistic regression analysis, restricted cubic spline (RCS) analyses and subgroup analysis. ROC curves were used to assess the predictive capacity of age, abnormal tails and PR for the SDF.

RESULTS

The SDF was associated with sperm morphology, with a significant correlation observed with abnormal sperm tails (r = 0.491, P < 0.001). Binary regression analysis revealed that abnormal sperm tails were an independent influencing factor of the SDF. RCS analyses and Trend analysis suggested that as the number of abnormal sperm tails increased, the risk of an abnormal SDF also increased, and the trend was statistically significant (P for trend < 0.001). The ROC curve demonstrated that abnormal sperm tails had good discriminatory ability for the SDF (AUC: 0.757, P < 0.001).

CONCLUSION

Abnormal sperm tails are an independent influencing factor of the SDF, and a higher number of abnormal tails is associated with an increased risk of an abnormal SDF.

Hypogonadism in Fathers and Perinatal Outcomes in Offspring: A Retrospective Analysis of U.S. Claims Data

OBJECTIVE

To evaluate the association between hypogonadism in fathers and perinatal outcomes in the United States.

MATERIALS AND METHODS

This retrospective study analyzed data from the Merative MarketScan Commercial Claims and Encounters database between 2011 and 2017, where records from births were stratified based on whether the father had been diagnosed with hypogonadism or not. We performed the multivariable logistic regression analysis of primary perinatal complications, including preterm birth, low birth weight, and intrauterine growth restriction against the father's age, hypogonadism, and paternal comorbidities.

RESULTS

A total of 468,546 birth records were enrolled, and hypogonadism in fathers was found in 18,610 birth records (3.97%). Fathers with hypogonadism had a lower percentage of uncomplicated perinatal outcomes (53% vs 57.94%, P value <.001) and higher percentage of low birth weight (46.96% vs 41.75%, P value <.001) and preterm birth (7.64% vs 5.66%, P value <.001) compared to fathers without hypogonadism. Paternal hypogonadism was associated with a higher risk of preterm birth (odds ratio = 1.18; 95% CI: 1.11, 1.25, P value <.001), low birth weight (odds ratio = 1.06; 95% CI: 1.03, 1.10, P value <.001), and any perinatal complications (odds ratio = 1.06; 95% CI: 1.03, 1.09, P value <.001).

CONCLUSION

Hypogonadism in fathers is associated with an 18%, 6.2%, and 6% higher risk of preterm birth, low birth weight, and any perinatal complications, respectively. However, these results should be interpreted with caution as we were unable to control for the maternal risk factors affecting perinatal outcomes.

Influence of Varicocelectomy on Assisted Reproductive Technology Outcomes of Infertile Patients with Varicocele: A Systematic Review and Meta-Analysis

Varicocele can lead to impaired semen parameters and induce infertility. Varicocelectomy is considered the gold standard for varicocele treatment. However, its impact on improving assisted reproductive technologies (ARTs) outcomes remains contentious. This study seeks to compare reproductive outcomes between infertile men who underwent varicocelectomy and those who did not prior to ARTs. In addition, it evaluates the influence of types of fertilization, couples' ages, and treatment years on clinical pregnancy rates. A comprehensive search was conducted through February 2023 across eight electronic databases using combinations of relevant keywords. Observational and randomized controlled trials (RCTs) were included. Fourteen eligible studies (n = 1,705) were included: 12 retrospective studies (n = 1,467) and 2 prospective studies (n = 238). Pooled results indicated that infertile men who received varicocelectomy had a significantly higher clinical pregnancy rate compared to the control group (OR: 1.38, 95% CI [1.05, 1.83]; I2 = 36%, p = .02). The live birth rate was also significantly higher in the treatment group (OR: 2.18, [1.58, 3.01]; p < .00001; I2 = 0%). However, miscarriage rates did not significantly differ (OR: 1.07; [0.57, 1.98]; I2 = 0%, p = .84). Varicocelectomy significantly improved sperm concentration and normal morphology rate, but did not result in a significant enhancement in sperm motility. Men who underwent varicocelectomy between 2012 and 2019 and subsequently received intracytoplasmic sperm injection exhibited improved outcomes, particularly when their female partners were under 30 years of age. Larger, high-quality RCTs are needed to clarify benefits or avoid unnecessary treatments.

Paternal age and neonatal outcomes: a population-based cohort study

STUDY QUESTION

Is paternal age associated with neonatal outcomes?

SUMMARY ANSWER

Paternal age is independently associated with preterm birth (PTB) and caesarean section.

WHAT IS KNOWN ALREADY

Advanced maternal age has long been recognized as a major risk factor for adverse neonatal outcomes. However, the association between paternal age and neonatal outcomes are not well established, yet it is biologically plausible that an increasing number of genetic and epigenetic sperm abnormalities in older males may contribute to adverse neonatal outcomes.

STUDY DESIGN SIZE DURATION

This population-based cohort study was based on the National Free Preconception Checkups Project between 1 January 2014 and 31 December 2019 in Guangdong Province, China. Paternal age at the maternal last menstrual period was measured. The main outcomes included caesarean section, PTB, small for gestational age (SGA) and perinatal infant death (PID).

PARTICIPANTS/MATERIALS SETTING METHODS

A total of 783 988 mother-neonate-father trios were included in this study. A modified Poisson regression model was employed to estimate relative risk (RR) and 95% CI and logistic regression models were used to analyse the relative importance of predictors. We used restricted cubic splines to flexibly model the non-linear dose-response association between paternal age and neonatal outcomes. We also assessed additive interactions between paternal and maternal age on neonatal outcomes.

MAIN RESULTS AND THE ROLE OF CHANCE

Neonates born to fathers aged 35-44 years had higher risks of caesarean section (RR: 1.07; 95% CI: 1.06-1.09) and PTB (RR: 1.15; 95% CI: 1.10-1.19) compared with neonates of fathers aged 25-34 years, after adjustment for confounders. The increased risks of PTB associated with paternal age appeared to be 'dose' dependent, with a J-shaped association curve (P for non-linearity<0.001). The relative importance of paternal age in predicting PTB and caesarean section was similar to, or even higher than, that of maternal age. The combined effects of advanced maternal and paternal age appeared to be less than additive joint effects (relative excess risk due to interaction<0). The association of paternal age with SGA or PID was not statistically significant (P > 0.05).

LIMITATIONS REASONS FOR CAUTION

As with all observational studies, residual confounding could not be ruled out. Only couples who planned to conceive were included.

WIDER IMPLICATIONS OF THE FINDINGS

In this population-based cohort study, paternal age was independently associated with caesarean section and PTB. These findings may be clinically useful in preconception counselling on parental age-related pregnancy risks. Our findings emphasize the need to further investigate the public health implications of increasing paternal age.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by the Guangdong Province Medical Research Funding (No. B2023416). No competing interests are reported.

TRIAL REGISTRATION NUMBER

N/A.

Patient-specific predictors of successful frozen embryo transfer using the freeze-all protocol: a retrospective observational study

BACKGROUND

The aim of this study was to examine various patient factors affecting first programmed embryo transfer (ET) outcomes under the freeze-all policy at a single tertiary university infertility center.

METHODS

This retrospective observational study reviewed the medical records of 243 couples who underwent their first ET using blastocysts collected under the freeze-all antagonist-controlled ovarian stimulation (COS) protocol from 2015 to 2023. Patients were grouped into pregnant and nonpregnant groups, and their data, including demographics, COS and ET outcomes, and embryo storage duration, were analyzed.

RESULTS

Patient body mass index, cause of infertility, follicle-to-oocyte index, distribution of blastocyst grades, number of transferred embryos, and embryo storage duration were not significantly different between the groups. In a simple comparative analysis, patients with successful clinical pregnancy tended to have significantly lower female and male age (33.83±3.67 and 35.32±4.54 years vs. 37.07±4.15 and 39.33±5.60 years, respectively), higher anti-Müllerian hormone levels (6.27±5.32 ng/mL vs. 4.14±3.82 ng/mL) and antral follicle counts (14.20±8.26 vs. 10.04±5.75), and higher numbers of retrieved oocytes and metaphase II oocytes (13.74±6.92 and 9.64±6.19 vs. 11.21±6.04 and 7.53±5.56, respectively). Multivariate logistic regression analysis of these variables revealed that only male age was a significant factor for successful clinical pregnancy (odds ratio, 4.768; 95% confidence interval, 1.252-18.162; p=0.022).

CONCLUSION

During the first programmed ET using blastocysts collected under the freeze-all antagonist COS protocol, male age and correspondingly the quality of gametes for fertilization were crucial for successful pregnancy, having more importance than calculated female ovarian reserve and embryo storage duration.

The correlation between sperm DNA methylation and DNA damage: a comparison of comet and TUNEL

Objective

To evaluate the relationship between sperm DNA methylation and DNA damage as determined by the comet or TUNEL assays.

Design

Retrospective research study.

Setting

University-based andrology and in vitro fertilization (IVF) laboratory.

Patients

Data came from 1,470 male partners (ages 18 and older) recruited from heterosexual couples (ages 18-45 years) seeking fertility treatments. These data were analyzed retrospectively from the Folic Acid and Zinc Supplementation Trial (FAZST) study.

Main outcome measures

Comet and TUNEL measures and associations with DNA methylation patterns.

Results

Comet and TUNEL values were correlated with one another across all samples (R 2 = 0.34, P < 0.001); however, when assessing the highest and lowest scores reported from each assay, there was little overlap between patients. This suggests that Comet and TUNEL are identifying key differences that may be meaningful and correlated with other sperm metrics. We compared both comet and TUNEL to methylation array data using a sliding window analysis, which identified far more significantly differentially methylated sites as a function of comet than TUNEL (3,387 vs. 23). Interestingly, sites associated with comet were associated with biological pathways related to DNA methylation involved in germline development, as determined by a GO term analysis. The TUNEL assay, by comparison, produced no relevant biological pathways.

Conclusions

Because the comet and TUNEL assays are both used to indicate levels of DNA damage, and outputs of both are correlated to each other, it would seem to follow that both are equally predictive of deviations in DNA methylation patterns. The findings of this study suggest that this is not the case. The comet assay shows a significantly higher association with DNA methylation disruption, and we therefore believe it to be a better indicator of sperm epigenetic health.

ARHGAP26 deficiency drives the oocyte aneuploidy and early embryonic development failure

Aneuploidy, the presence of a chromosomal anomaly, is a major cause of spontaneous abortions and recurrent pregnancy loss in humans. However, the underlying molecular mechanisms still remain poorly understood. Here, we report that ARHGAP26, a putative tumor suppressor gene, is a newly identified regulator of oocyte quality to maintain mitochondrial integrity and chromosome euploidy, thus ensuring normal embryonic development and fertility. Taking advantage of knockout mouse model, we revealed that genetic ablation of Arhgap26 caused the oocyte death at GV stage due to the mitochondrial dysfunction-induced ROS accumulation. Lack of Arhgap26 also impaired both in vitro and in vivo maturation of survived oocytes which results in maturation arrest and aneuploidy, and consequently leading to early embryonic development defects and subfertility. These observations were further verified by transcriptome analysis. Mechanistically, we discovered that Arhgap26 interacted with Cofilin1 to maintain the mitochondrial integrity by regulating Drp1 dynamics, and restoration of Arhgap26 protein level recovered the quality of Arhgap26-null oocytes. Importantly, we found an ARHGAP26 mutation in a patient with history of recurrent miscarriage by chromosomal microarray analysis. Altogether, our findings uncover a novel function of ARHGAP26 in the oocyte quality control and prevention of aneuploidy and provide a potential treatment strategy for infertile women caused by ARHGAP26 mutation.

Associations between Advanced Paternal Age and Adverse Reproductive Outcomes in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b)

OBJECTIVE

 The association between paternal age and adverse pregnancy outcomes (APOs) has not been well studied. We sought to determine whether advanced paternal age (APA) is associated with adverse maternal or neonatal outcomes.

STUDY DESIGN

 Secondary analysis of 8,863 pregnancies from the Nulliparous Pregnancy Outcomes Study Monitoring Mothers-to-Be (nuMoM2b) prospective cohort in which both maternal and paternal age at conception were known. APA was defined as age ≥ 40 years and AMA was defined as age ≥ 35 years. Composite maternal and fetal/neonatal APO outcomes were adjudicated by experts using previously defined methods. Univariable and multivariable logistic regression models were used to estimate the associations between APA, AMA, and their combination (AMA and APA), with the outcomes of interest (APO, fetal/neonatal, and combined APO or fetal/neonatal outcomes). Multivariable analyses were adjusted for covariates identified a priori: self-reported race and ethnicity, education, body mass index, maternal medical conditions, assisted reproductive technology (ART), and maternal age in APA only models.

RESULTS

 APA in isolation was not significantly associated with maternal or fetal/neonatal adverse outcomes (adjusted odds ratio [aOR] = 1.08, 95% confidence interval [CI]: 0.89 - 1.32). In contrast, AMA pregnancies and pregnancies in which both parents were of advanced age were associated with significantly increased risk of maternal or fetal/neonatal adverse outcome (aOR = 1.37, 95% CI: 1.17 - 1.59, p < 0.001 and aOR = 1.60, 95% CI: 1.25 - 2.05, p < 0.001), respectively. Findings were similar when individuals who used assisted reproductive technology (ART) were excluded from analyses.

CONCLUSION

 In our study of nulliparous birthing people, in contrast to AMA pregnancies, APA alone was not significantly associated with a heightened risk of maternal or fetal/neonatal APOs. However, pregnancies from both AMA and APA individuals demonstrated a trend toward a higher risk of APOs compared with AMA pregnancies. Further research is needed to delineate the mechanism driving this finding.

KEY POINTS

· There is an established association between older maternal age and increased risk of adverse pregnancy outcomes. Determining the influence of paternal age on pregnancy outcomes is of equal importance.. · Prior data are inconclusive on the association of APA and rates of miscarriage, fertilization rates, and aneuploidy, and to our knowledge, the associations with adverse pregnancy outcomes have not been previously examined.. · This study examines if APA (paternal age ≥ 40 years) is an independent risk factor for adverse pregnancy outcomes in a cohort of nulliparous birthing people..

Micronutrient-Antioxidant Therapy and Male Fertility Improvement During ART Cycles

Today, accumulating evidence highlights the impact of oxidative stress (OS) on semen quality. It is considered to be a key factor contributing to the decline in male fertility. OS is detected in 30-80% of men with infertility, highlighting its strong association with impaired reproductive function and with clinical outcomes following the use of assisted reproductive technologies. Spermatozoa are particularly vulnerable to oxidative damage due to their high content of polyunsaturated fatty acids (PUFAs) and limited antioxidant defense abilities. OS arises from an imbalance between the production of reactive oxygen species and the capacity to neutralize or repair their adverse effects. Evidence indicates that OS leads to lipid peroxidation, protein oxidation, mitochondrial dysfunction, and genomic instability. Micronutrient-antioxidant therapies can play a key role in infertility improvement by neutralizing free radicals and preventing cellular damage. Many different micronutrients, including L-carnitine, L-glutathione, coenzyme Q10, selenium, and zinc, as well as vitamins complexes, are proposed to improve sperm parameters and male fertility potential. This study aims to review the impact of antioxidant supplementation on semen parameters, including sperm volume, motility, concentration, morphology, genome integrity (maturity and fragmentation), and in vitro fertilization (IVF) outcomes. Antioxidant intake and a balanced lifestyle reduce oxidative stress and mitochondrial dysfunction, enhancing the spermatogenesis and spermiogenesis processes, improving sperm quality, and protecting DNA integrity.

Endometriosis does not impact aneuploidy rates of products of conception in IVF population

It has been debated whether endometriosis (EMS) adversely affects oocyte quality, potentially leading to a higher incidence of genetically unbalanced embryos or other egg factors that affect the developmental potential. In this study, we explored the effects of endometriosis on risk of chromosomally aberrant in miscarried products of conception (POC) after assisted reproductive treatment (ART), including fresh and frozen cycles. Miscarried POCs were collected from EMS patients (N = 102) and non-EMS patients (N = 441). Single nucleotide polymorphism (SNP) array analysis was conducted on all collected samples. Propensity score matching (PSM, ratio of 1:4) based on maternal age was applied in data analysis. Logistic regression analysis was performed to identify risk factors for chromosomal aberration-induced miscarriage between the two cohorts. A total of 228 (41.99% of 543) conceptuses were identified as having chromosomal aberrations. The results showed that women with EMS had a significantly lower antral follicle count (AFC) (10 ± 5 vs. 14 ± 7, P < 0.01) compared to the control group. Additionally, the EMS group had a relatively lower anti-Mullerian hormone (AMH), higher basal follicle stimulating hormone (FSH) and fewer oocytes, (P > 0.05). There was no significant difference in the chromosomal aberration rate of POCs between EMS and non-EMS groups (35.29% vs. 43.54%; odds ratio (OR) = 1.03, 95% confidence intervals (CIs) 0.79-1.35). This is the first study to show that EMS maybe associated with decreased ovarian reserve, but not related to chromosomal abnormalities in POCs. These results suggest that chromosomal abnormalities may not be the only cause of miscarriage in EMS patients.

Investigating male factors and their relationships with reproductive health outcomes: a case-control study protocol for Towards Optimal Fertility, Fathering, and Fatherhood studY (TOFFFY) in Singapore

INTRODUCTION

Despite the global prevalence of low fertility rates, male contributions to fertility and reproductive health outcomes have been understudied. This study aims to investigate the male contribution to fertility and explore the underlying biological mechanisms. Specifically, we aim to (1) identify male factors associated with successful pregnancy, (2) develop a fertility index incorporating modifiable factors for both males and females to predict pregnancy rate and (3) explore the relationship of male modifiable factors with semen parameters and molecular characteristics.

METHODS AND ANALYSIS

We will conduct an unmatched case-control study involving 240 couples with impaired male fertility (cases) and 240 couples with normal male fertility (controls). Between July 2024 and June 2026, we will recruit 480 eligible couples from KK Women's and Children's Hospital, Singapore. Male and female participants will complete questionnaires on sociodemographics, general health and lifestyle factors, and their anthropometry and body fat composition will be measured. Blood and semen samples from the male participants will be collected for biochemical, molecular and semen analyses. Predictive male factors will be identified using the least absolute shrinkage and selection operator method, accounting for female factors. We will construct a logistic regression model incorporating both male and female factors to derive a fertility index, which will be evaluated using cross-validation on subsets of the study population. Multivariable linear regression will be used to explore relationships between male modifiable exposures and semen parameters.

ETHICS AND DISSEMINATION

The study protocol has received approval from the Centralised Institutional Review Board of SingHealth (2024/2120), Singapore. Participants will provide written informed consent. Study results will be disseminated through conferences and peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

NCT06293235.

Paternal family history of premature atherosclerotic disease and perinatal death: A population-based cohort study

BACKGROUND

Studies have reported that pregnancies conceived by fathers with modifiable cardiovascular risk factors are at higher risk of ending in losses compared to those without such risk factors. Our objective was to examine the association between paternal family history _a non-modifiable risk factor_ of premature atherosclerotic disease and perinatal death.

METHODS

This is a population-based cohort study. Information on fathers, aged 18-50 years who participated in three population-based health surveys conducted in Norway during 1974-2003 was linked to their singleton births registered in the Medical Birth Registry of Norway. We used multilevel mixed effect logistic regression analyses with random intercepts by father's identification number. The birth was the observation unit in all analyses.

RESULTS

A total of 220,386 fathers who had 512,111 births with information on family history of CHD (12.3% with positive family history) and 203,257 births with information on family history of stroke (9.2% with positive family history) were analysed. There were 782 (1.3%) and 195 (1%) perinatal deaths in births to fathers with family history of CHD and stroke while 5,922 (1.3%) and 1,858 (1%) in those without family histories. We found no association between family history of CHD and stillbirth (OR 1.01, 95% CI 0.92; 1.12), neonatal death (OR 0.98, 95%CI 0.86, 1.11) or perinatal death (OR 1.00, 95% CI 0.92, 1.08). Similarly, we found no associations between family history of stroke and stillbirth (OR 1.00, 95% CI 0.82, 1.21), neonatal death (OR 1.09, 95%CI 0.84, 1.41) or perinatal death (OR 1.02, 95% CI 0.88, 1.20).

LIMITATIONS

Socioeconomic background of fathers was captured using imperfect proxy. Potential misclassification of family history and selection bias should be considered.

CONCLUSION

Results of this large, cohort study including half-a million births, do not indicate an association between paternal family history of premature atherosclerotic disease and perinatal death.

Is lifestyle different in male partners experiencing recurrent pregnancy loss compared to men fathering a live birth?

BACKGROUND

Recurrent pregnancy loss is characterized by three or more consecutive pregnancy losses. Although the causes of recurrent pregnancy loss are often unknown, chromosomal defects and fetal anomalies account for a significant proportion of cases. Previous research has primarily focused on maternal factors, but recent attention has shifted to the role of male lifestyle factors.

OBJECTIVES

This study examined how male lifestyle factors and chronic illnesses affect recurrent pregnancy loss in a Danish cohort. Objectives included analyzing demographic and clinical features, as well as assessing lifestyle factors and pregnancy outcomes.

MATERIALS AND METHODS

We included 741 males referred to the Danish recurrent pregnancy loss unit between 2009 and 2021, alongside a control group of 1173 males from the PREGCO study. Data on demography, clinical features, lifestyle factors, and pregnancy outcomes were collected and analyzed.

RESULTS

The recurrent pregnancy loss group had a higher mean age compared to the controls. Although there was a trend suggesting a higher prevalence of obesity in the recurrent pregnancy loss group, statistical significance was not reached. The prevalence of chronic illnesses was similar in both groups. In the recurrent pregnancy loss group, a higher body mass index and history of previous or current smoking were associated with a lower pregnancy rate, and men who never smoked had an increased likelihood of achieving pregnancy. However, these associations lost significance after adjusting for potential confounders.

DISCUSSION

The study suggests an association between male obesity and smoking, and decreased pregnancy rates after referral for recurrent pregnancy loss. However, further research is needed to understand the underlying mechanisms and establish causality in this association.

CONCLUSION

The study reveals potential associations between male smoking, male obesity, and reduced pregnancy rates in individuals referred for recurrent pregnancy loss. These findings emphasize the importance of considering male lifestyle factors in the evaluation and management of recurrent pregnancy loss.

Lipid imbalance and inflammatory oxylipin cascade at the maternal-fetal interface in recurrent spontaneous abortion

Background

Recurrent spontaneous abortion (RSA) is intricately linked to metabolic dysregulation at the maternal-fetal interface during early gestation. Abnormal levels of essential fatty acids and downstream oxylipins in decidua and chorionic villi have been identified as potential risk factors for RSA. Oxylipins have been linked to excessive inflammation, which might disrupt maternal-fetal immune tolerance, potentially contributing to RSA. Nonetheless, the exact fatty acid-oxylipin metabolic pathway at the matrernal-fetal interface in RSA occurrence remains unknown. Therefore, this research aimed to explore the effect of essential fatty acids, their transport, and downstream oxylipins at the maternal-fetal interface on RSA pathogenesis.

Methods

Plasma, chorionic villus, and decidual tissue samples from the first trimester were collected from healthy pregnant women undergoing elective pregnancy terminations, as well as from patients experiencing spontaneous abortion. The concentrations of essential fatty acids and their downstream oxylipins in the villi and decidua were quantified using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS). The expression of enzymes related to metabolic pathways was investigated by q-PCR. The ratios of M1/M2 macrophages were assessed by flow cytometry (FCM).

Results

This study found elevated concentrations of omega-6 fatty acids, encompassing arachidonic acid (AA), linoleic acid (LA), and dihomo-gamma-linolenic acid (DGLA) in maternal plasma and chorionic villi, whereas lower concentrations were observed in the decidua, than in samples from normal pregnancies. Further analysis revealed that the transport of these fatty acids was dysregulated at the maternal-fetal interface in RSA women, possibly due to the aberrant expression of the fatty acid translocase (FAT/CD36). In addition, this study revealed that RSA patients displayed higher levels of downstream oxylipins, such as prostaglandin F2a (PGF2a), prostaglandin E2 (PGE2), and leukotriene B4 (LTB4) in chorionic villi and decidua. These compounds may contribute to M1 inflammatory macrophage polarization in RSA, thereby forming a highly inflammatory environment and influencing immunomodulation at the maternal-fetal interface.

Conclusion

The study revealed alterations in omega-6 fatty acids, CD36 transport, and AA downstream oxylipins in RSA, which in turn promote M1 macrophage polarization. Thus, this research has established a foundation for identifying potential biomarkers for, and providing novel insights into, the diagnosis and pathophysiology of RSA.

The landscape of recurrent spontaneous abortion registered on clinical trials.gov

Objective

Recurrent spontaneous abortion (RSA) presents a significant challenge in the field of reproductive medicine, as effective treatments remain limited despite extensive research efforts. A comprehensive understanding of current RSA clinical trials is essential for enhancing trial design and identifying existing research gaps. The aim of this study is to characterize RSA related clinical trials registered on Clinical Trials.gov.

Methods

A thorough search was conducted to identify and review clinical trials focusing on RSA that were registered on Clinical Trials.gov up to March2, 2024.

Results

A total of 138 trials were identified in the analysis, with 72 (52.17%) classified as intervention trials and 66 (47.83%) as observational trials. Approximately half of the studies (67,48.55%) had an enrollment of 100 participants or fewer. The majority of trials included only female participants. Asia hosted the highest number of clinical trials (46,33.33%), followed by Europe (36,26.09%), Africa (29,21.01%), America (13,9.42%). The majority of trials (61,44.20%) focused on individuals with unexplained recurrent spontaneous abortion (URSA). The predominant intervention types examined in the reviewed studies were drug interventions (49,62.82%), with a notable rise in behavioral intervention trials.

Conclusion

Our research findings suggest that existing research efforts in the realm of RSA are inadequate for the progression of prevention and treatment strategies. The majority of clinical trials have primarily targeted individuals with URSA, with a particular emphasis on drug interventions, notably anticoagulants.

The impact of advanced paternal age on the live birth rate in patients undergoing Assisted Reproduction treatment: Findings from an analysis at a public reproductive center in Brazil

OBJECTIVE

Human reproduction presents a challenge for our species, as evidenced by the escalating rates of infertility. This trend has prompted inquiries into diverse strategies aimed at mitigating infertility and enhancing conception rates. Despite the extensive research on advanced maternal age as a risk factor for reproductive outcomes, paternal age has historically garnered comparatively less attention. The aim of this study was to assess the impact of paternal age on embryos and its subsequent repercussions on fertilization rate, biochemical pregnancy, clinical pregnancy, and live birth rate in individuals undergoing assisted reproductive treatment in a public reproductive center located in Brazil.

METHODS

This investigation adopted a retrospective cohort, cross-sectional, analytical design, utilizing the analysis of secondary data, covering the period from July 2015 to July 2021.

RESULTS

A total of 350 couples grappling with infertility and undergoing intrauterine insemination (IUI), in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI) were included in the analysis. Examination of age groups revealed a notable correlation between the ages of women and men (correlation coefficient R=0.12, p<0.0001). In the analysis of IVF techniques, a discernible trend towards a negative correlation with paternal age was observed, signifying that higher paternal age was linked to lower fertilization rates (p=0.004).

CONCLUSIONS

Advanced paternal age significantly impacts full-term birth rates in IVF procedures, emphasizing the need for preconception public health advisories that underscore the risks associated with delaying parenthood for both men and women, particularly among those necessitating assisted reproductive techniques.

The Fertility Education Initiative: responding to the need for enhanced fertility and reproductive health awareness amongst young people in the United Kingdom

The need for fertility education arises from changing patterns of family formation in recent times. Young people feel unprepared for how best to plan their career and family and have little idea of the various factors that may influence their fertility later in their life. Research shows young people would like to know more and need the information to be conveyed in a way that is engaging and helps them to integrate it at their current life stage. The Fertility Education Initiative (FEI) was founded in 2016 to address the need for improved fertility and reproductive health awareness and ensure young people are equipped with the relevant information to meet their reproductive and family building needs. This paper serves as a historical record of the genesis of the FEI and its impact to date.

Young adult's views on using a poster to learn about fertility: redesigning the fertility education poster

Fertility awareness should be taught to everyone. The International Reproductive Health Education Collaboration (IRHEC) designed a fertility poster in 2019 but did not have a specific target group in mind. Studies have been conducted in Denmark and Sweden to determine how the poster can be redesigned. In this study, we carried out focus groups with young adults in the UK to ask their views of the poster, with the aim of redesigning it. Six focus groups were undertaken with twenty seven, 18-25 year olds. Five questions were asked: 1. What are your thoughts, feelings, and reactions to the poster? 2. Did you learn anything from the poster? 3. How has reading the poster impacted your opinions or thoughts about having children? 4. What are your opinions about using a poster format to inform and start reflections regarding family building? 5. Reading through each point are there any changes to be made? Content analysis was performed. Themes identified revealed the information on the poster gave the participants some anxiety and apprehension, especially regarding the effect of age on fertility, perceptions of IVF, and gaps in knowledge. The fertility education poster is a good resource for education, but other resources should be developed.

Paternal age, de novo mutations, and offspring health? New directions for an ageing problem

This Directions article examines the mechanisms by which a father's age impacts the health and wellbeing of his children. Such impacts are significant and include adverse birth outcomes, dominant genetic conditions, neuropsychiatric disorders, and a variety of congenital developmental defects. As well as age, a wide variety of environmental and lifestyle factors are also known to impact offspring health via changes mediated by the male germ line. This picture of a dynamic germ line responsive to a wide range of intrinsic and extrinsic factors contrasts with the results of trio studies indicating that the incidence of mutations in the male germ line is low and exhibits a linear, monotonic increase with paternal age (∼two new mutations per year). While the traditional explanation for this pattern of mutation has been the metronomic plod of replication errors, an alternative model pivots around the 'faulty male' hypothesis. According to this concept, the genetic integrity of the male germ line can be dynamically impacted by age and a variety of other factors, and it is the aberrant repair of such damage that drives mutagenesis. Fortunately, DNA proofreading during spermatogenesis is extremely effective and these mutant cells are either repaired or deleted by apoptosis/ferroptosis. There appear to be only two mechanisms by which mutant germ cells can escape this apoptotic fate: (i) if the germ cells acquire a mutation that by enhancing proliferation or suppressing apoptosis, permits their clonal expansion (selfish selection hypothesis) or (ii) if a genetically damaged spermatozoon manages to fertilize an oocyte, which then fixes the damage as a mutation (or epimutation) as a result of defective DNA repair (oocyte collusion hypothesis). Exploration of these proposed mechanisms should not only help us better understand the aetiology of paternal age effects but also inform potential avenues of remediation.

Emerging therapeutic strategies to mitigate female and male reproductive aging

People today are choosing to have children later in life, often in their thirties and forties, when their fertility is in decline. We sought to identify and compile effective methods for improving either male or female fertility in this context of advanced reproductive age. We found few clinical studies with strong evidence for therapeutics that mitigate reproductive aging or extend fertility; however, this Perspective summarizes the range of emerging experimental strategies under development. Preclinical studies, in mouse models of aging, have identified pharmaceutical candidates that improve egg and sperm quality. Further, a diverse array of medically assisted reproduction methodologies, including those that stimulate rare ovarian follicles and rejuvenate egg quality using mitochondria, may have future utility for older patients. Finally, we highlight the many knowledge gaps and possible future directions in the field of therapeutics to extend the age of healthy human reproduction.

Genetics of female and male reproductive traits and their relationship with health, longevity and consequences for offspring

Substantial shifts in reproductive behaviors have recently taken place in many high-income countries including earlier age at menarche, advanced age at childbearing, rising childlessness and a lower number of children. As reproduction shifts to later ages, genetic factors may become increasingly important. Although monogenic genetic effects are known, the genetics underlying human reproductive traits are complex, with both causal effects and statistical bias often confounded by socioeconomic factors. Here, we review genome-wide association studies (GWASs) of 44 reproductive traits of both female and male individuals from 2007 to early 2024, examining reproductive behavior, reproductive lifespan and aging, infertility and hormonal concentration. Using the GWAS Catalog as a basis, from 159 relevant studies, we isolate 37 genes that harbor association signals for four or more reproductive traits, more than half of which are linked to rare Mendelian disorders, including ten genes linked to reproductive-related disorders: FSHB, MCM8, DNAH2, WNT4, ESR1, IGSF1, THRB, BRWD1, CYP19A1 and PTPRF. We also review the relationship of reproductive genetics to related health and behavioral traits, aging and longevity and the effect of parental age on offspring outcomes as well as reflecting on limitations, open questions and challenges in this fast-moving field.

Miscarriage, stillbirth, and mortality risk from stroke in women: findings from the PLCO study

OBJECTIVES

Existing evidence suggests that miscarriage and stillbirth are associated with an increased risk of stroke in women. However, the impact of these events on stroke mortality remains unclear. This study aimed to elucidate the potential association between miscarriage and stillbirth and stroke mortality in women.

METHODS

We employed a competing risk model using data from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial to assess the relationship between miscarriage/stillbirth and stroke death. Death from other causes was considered as a competing risk, and we conducted a subgroup analysis to explore the potential impact.

RESULTS

Our study included 68,629 women for miscarriage and 65,343 women for stillbirth. No significant association was observed between miscarriage and stroke mortality (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.84 to 1.10; p=0.58). While a single stillbirth did not show a significant association (HR, 0.81; 95% CI, 0.57 to 1.15; p=0.23), recurrent stillbirth (≥2) was associated with a significantly increased risk of stroke mortality compared to women with no stillbirths (HR, 2.24; 95% CI, 1.45 to 3.46; p<0.001).

CONCLUSIONS

Our findings suggest that recurrent stillbirth, but not single events, is associated with an elevated risk of stroke mortality in women. Further research is warranted to clarify the underlying mechanisms and potential long-term health implications of recurrent pregnancy loss.

Paternal Contributions to Recurrent Pregnancy Loss: Mechanisms, Biomarkers, and Therapeutic Approaches

Background and Objectives: Recurrent pregnancy loss (RPL) affects numerous couples worldwide and has traditionally been attributed mainly to maternal factors. However, recent evidence highlights significant paternal influences on pregnancy viability and outcomes. This review aims to comprehensively examine male contributions to pregnancy loss, focusing on underlying mechanisms, novel biomarkers, and integrated strategies for improved reproductive success. Materials and Methods: A comprehensive narrative review was conducted by searching databases including PubMed and Embase for the literature published from January 2004 to October 2024. Studies focusing on paternal influences in RPL-encompassing oxidative stress, genetic and epigenetic mechanisms, health conditions, lifestyle factors, environmental exposures, and advancements in sperm proteomics-were included. Inclusion criteria were peer-reviewed articles in English that directly addressed paternal factors in RPL; studies not meeting these criteria were excluded. Results: The review identified that paternal factors such as advanced age, metabolic and cardiovascular health issues, chronic diseases, lifestyle habits (e.g., smoking, alcohol consumption, poor diet), and environmental exposures significantly affect sperm integrity through mechanisms like oxidative stress, DNA fragmentation, and epigenetic alterations. Advanced paternal age and poor health conditions are associated with increased risks of miscarriage and adverse pregnancy outcomes. Novel sperm proteomic biomarkers have been identified, offering potential for enhanced diagnostics and personalized interventions. Integrated approaches involving multidisciplinary assessments, preventive strategies, and genetic counseling are essential for effectively addressing RPL. Conclusions: Integrating paternal factors into clinical evaluations is crucial for effectively addressing recurrent pregnancy loss. Recognizing and modifying paternal risk factors through lifestyle changes, medical interventions, and environmental management can improve pregnancy outcomes. The findings underscore the need for incorporating paternal assessments into standard care and highlight the importance of future research focusing on standardizing diagnostic protocols, expanding studies on paternal contributions, and integrating proteomic biomarkers into clinical practice to facilitate personalized treatment strategies.

Unveiling the truth: Pathogen infections linked to miscarriage: A STROBE-Compliant Mendelian randomization study

Miscarriage represents a prevalent yet insufficiently studied adverse pregnancy outcome. The definitive causal links between various pathogens and miscarriage remain to be established. To investigate the causal connections between pathogen infections and miscarriage, we utilized a two-sample bidirectional Mendelian randomization (MR) analysis. We sourced genome-wide association studies data on pathogen infections from the UK Biobank, which included serological markers for infectious diseases and comprehensive whole-genome genetic information from approximately 10,000 individuals. Additionally, genome-wide association studies data on miscarriages were collected from 3 distinct European populations for our analysis. The MR analysis was primarily conducted using the inverse variance weighted method, complemented by Bayesian weighted MR and the weighted median method for robustness. To ensure the reliability of our findings, we performed heterogeneity and pleiotropy tests, leave-one-out sensitivity analyses, and a meta-analysis. Our extensive research has identified a causal association between miscarriage and infections by several human herpesviruses (HHV-1, HHV-3, HHV-4, HHV-6, and HHV-7), polyomaviruses (BK, JC, and Merkel cell polyomaviruses), and Chlamydia trachomatis (inverse variance weighted, P < .05). Notably, a meta-analysis of the integrated data highlighted the particularly high accuracy and consistency of the association with Merkel cell polyomavirus. Our MR analysis has clarified the causal relationships between specific pathogen infections and miscarriage, providing a critical foundation for the prevention and treatment of this adverse pregnancy outcome.

Limiting access to assisted reproductive technologies for males of advanced age-Pros and cons from a Nordic perspective

It is not controversial to state that parental age is increasing in several countries. But how to deal with this increase might be. Some Nordic countries have set an upper age limit for females seeking assisted reproduction in their national legislation, but none have done so for males. There are also recommendations in place that restrict access to publicly funded assisted reproduction for both females and males of advanced age in some Nordic countries. As recent data now show somatic and psychiatric health risks related to advanced paternal age, we ask if the time has come for countries to set an upper age limit for males seeking assisted reproduction like there already is for females, and summarize some of the risks and rewards involved in treating couples with advanced age in fertility clinics.

Exploring the Father's Role in Determining Neonatal Birth Weight: A Narrative Review

Birth weight, which exhibits variability across different populations, is influenced by a mix of genetic, environmental, and dietary factors originating from both the mother and father. Maternal characteristics, including age, socioeconomic status, prior pregnancies, weight, height, and weight increase throughout pregnancy, have a substantial influence on fetal growth and the health of the infant. On the other hand, the influence of paternal characteristics on the weight of newborns is still not fully comprehended in a consistent manner. Birth weight is an important factor that can help predict various maternal complications, such as the probability of having a C-section, experiencing postpartum hemorrhage or infections. It can also indicate future health challenges like asthma, cognitive impairment, and chronic diseases such as hypertension and diabetes. Nineteen publications were found through a thorough search of the Medline, PubMed, and Scopus databases, which provide insights into how paternal variables contribute to variations in birth weight. Significantly, the age of the father was found to be associated with higher chances of preterm birth and having a smaller size for gestational age in premature infants, while full-term children were more likely to have a larger size for gestational age. In addition, there is a constant correlation between the height of the father and the birth weight of the child. Taller dads are more likely to have babies with a higher birth weight and a lower likelihood of being small for gestational age (SGA). Although there were some discrepancies in the data about the weight and BMI of fathers, it was found that the height of fathers played a significant role in determining the size of the fetus and the weight of the newborn. While there may be differences in the conducted studies, these findings provide valuable insights into the complex connection between parental characteristics and fetal development. This data can be utilized to enhance clinical treatment strategies and enhance our comprehension of outcomes for neonates. Further homogeneous investigations are required to conclusively validate and build upon these findings.

Identification of metabolomic changes and potential therapeutic targets during ovarian aging

PURPOSE

To reveal the metabolic differences of follicle fluid (FF) and granulosa cell (GC) between younger women and advanced age women in ART cycles, and then find potential therapeutic targets of ovarian aging.

METHODS

Forty-five patients were included in the study and they were divided into three groups according to their age (Group A: 20-30 years old; Group B: 30-35 years old; Group C: 35-45 years old). All patients underwent controlled ovarian stimulation using the follicular phase long-acting protocol, FF and GC were obtained 36-38 hours after HCG administration. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used for metabolomics analysis and metabolic pathway analysis (MetPA) was utilized to find related pathways.

RESULTS

Between group A and group C, there were 72 and 21 differential metabolites in FF and GC, respectively. KEGG enrichment analysis showed six pathways were co-enriched by the differential metabolites of FF and GC. Among them, we noticed that in the pathway GABAergic synapse, GABA (gamma-aminobutyric acid) was down-regulated in GC, while its downstream metabolite succinic acid was down-regulated in FF. Further ROC curve analysis was performed on these two metabolites, and the results showed that they all had a favorable predictive value.

CONCLUSION

This study indicated that GABA and succinic acid could be potential therapeutic targets for ovarian aging, GABA may delay ovarian aging and improve ovarian function through its antioxidant properties, which may be a future direction of clinical treatment.

Emerging Roles of IL-27 in Trophoblast Cells and Pregnancy Complications

PROBLEM

Pregnancy complications such as spontaneous abortion, preeclampsia, and preterm birth persist, despite current interventions aimed at their prevention and treatment largely proving unsuccessful. Interleukin-27 (IL-27), composed of p28 and EBI3 subunits, binds to IL-27R, which consists of gp130 and IL-27Rα (also known as WSX-1 or TCCR), and plays a pivotal role in tumor development and inflammation regulation. At the maternal-fetal interface, IL-27 expression has been detected in trophoblasts, endometrial stromal cells, and decidual cells. Abnormal levels of IL-27/IL-27R have been linked to adverse pregnancy outcomes, including spontaneous miscarriage, preeclampsia, and preterm birth. This review aims to explore the expression of IL-27 at the maternal-fetal interface and its signaling pathway, uncovering the complex role of IL-27 in pregnancy complications.

METHOD OF STUDY

A comprehensive literature review was conducted using PubMed/Medline, Scopus, and Embase databases, analyzing studies on IL-27 expression and its signaling pathways at the maternal-fetal interface. The review focused on identifying the presence of IL-27 in various cell types and linking abnormal IL-27/IL-27R expression to pregnancy complications such as spontaneous miscarriage, preeclampsia, and preterm birth.

DISCUSSION AND CONCLUSION

IL-27 plays a complex role at the maternal-fetal interface, with abnormal expression linked to several pregnancy complications. These findings highlight the need for further research to elucidate IL-27's mechanisms and develop targeted interventions. Future studies should aim to develop targeted interventions and improve therapeutic strategies for managing pregnancy complications.

A nomogram and risk stratification to predict subsequent pregnancy loss in patients with recurrent pregnancy loss

STUDY QUESTION

Could the risk of subsequent pregnancy loss be predicted based on the risk factors of recurrent pregnancy loss (RPL) patients?

SUMMARY ANSWER

A nomogram, constructed from independent risk factors identified through multivariate logistic regression, serves as a reliable tool for predicting the likelihood of subsequent pregnancy loss in RPL patients.

WHAT IS KNOWN ALREADY

Approximately 1-3% of fertile couples experience RPL, with over half lacking a clear etiological factor. Assessing the subsequent pregnancy loss rate in RPL patients and identifying high-risk groups for early intervention is essential for pregnancy counseling. Previous prediction models have mainly focused on unexplained RPL, incorporating baseline characteristics such as age and the number of previous pregnancy losses, with limited inclusion of laboratory and ultrasound indicators.

STUDY DESIGN, SIZE, DURATION

The retrospective study involved 3387 RPL patients who initially sought treatment at the Reproductive Immunology Clinic of Renji Hospital, Shanghai Jiao Tong University School of Medicine, between 1 January 2020 and 31 December 2022. Of these, 1153 RPL patients met the inclusion criteria and were included in the analysis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

RPL was defined as two or more pregnancy losses (including biochemical pregnancy loss) with the same partner before 28 weeks of gestation. Data encompassing basic demographics, laboratory indicators (autoantibodies, peripheral immunity coagulation, and endocrine factors), uterine and endometrial ultrasound results, and subsequent pregnancy outcomes were collected from enrolled patients through initial questionnaires, post-pregnancy visits fortnightly, medical data retrieval, and telephone follow-up for lost patients. R software was utilized for data cleaning, dividing the data into a training cohort (n = 808) and a validation cohort (n = 345) in a 7:3 ratio according to pregnancy success and pregnancy loss. Independent predictors were identified through multivariate logistic regression. A nomogram was developed, evaluated by 10-fold cross-validation, and compared with the model incorporating solely age and the number of previous pregnancy losses. The constructed nomogram was evaluated using the AUC, calibration curve, decision curve analysis (DCA), and clinical impact curve analysis (CICA). Patients were then categorized into low- and high-risk subgroups.

MAIN RESULTS AND THE ROLE OF CHANCE

We included age, number of previous pregnancy losses, lupus anticoagulant, anticardiolipin IgM, anti-phosphatidylserine/prothrombin complex IgM, anti-double-stranded DNA antibody, arachidonic acid-induced platelet aggregation, thrombin time and the sum of bilateral uterine artery systolic/diastolic ratios in the nomogram. The AUCs of the nomogram were 0.808 (95% CI: 0.770-0.846) in the training cohort and 0.731 (95% CI: 0.660-0.802) in the validation cohort, respectively. The 10-fold cross-validated AUC ranged from 0.714 to 0.925, with a mean AUC of 0.795 (95% CI: 0.750-0.839). The AUC of the nomogram was superior compared to the model incorporating solely age and the number of previous pregnancy losses. Calibration curves, DCAs, and CICAs showed good concordance and clinical applicability. Significant differences in pregnancy loss rates were observed between the low- and high-risk groups (P < 0.001).

LIMITATIONS, REASONS FOR CAUTION

This study was retrospective and focused on patients from a single reproductive immunology clinic, lacking external validation data. The potential impact of embryonic chromosomal abnormalities on pregnancy loss could not be excluded, and the administration of medication to all cases impacted the investigation of risk factors for pregnancy loss and the model's predictive efficacy.

WIDER IMPLICATIONS OF THE FINDINGS

This study signifies a pioneering effort in developing and validating a risk prediction nomogram for subsequent pregnancy loss in RPL patients to effectively stratify their risk. We have integrated the nomogram into an online web tool for clinical applications.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Natural Science Foundation of China (82071725). All authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

Women's reproductive risk score and healthy lifestyle modification in cardiovascular disease: Findings from the UK Biobank

BACKGROUND AND AIMS

Reproductive risk factors are associated with increased risk of cardiovascular disease (CVD) in women. However, the combined effects of the composite reproductive risk factors on CVD are unknown. This study was performed to construct a reproductive risk score (RRS) to measure reproductive status, examine the association between RRS and CVD, and explore the modification effect of healthy lifestyle on the association in women in the UK Biobank cohort.

METHODS

The RRS was constructed in 74,141 female participants with data about the items derived for the RRS in the UK Biobank. The RRS was derived from 17 baseline variables, all of which indicated women's reproductive health status. We defined four categories of RRS status: low-risk group (score 0-1); low-intermediate group (score 2-3); high-intermediate group (score 4-5); and high-risk group (score 6-13). We also constructed a healthy lifestyle score (HLS) with five related factors, and categorized into unhealthy lifestyle group (score: 0-1), intermediate lifestyle group (score: 2-3) and healthy lifestyle group (score: 4-5).

RESULTS

Each point increase in the RRS was associated with a 22 % higher risk of CVD (adjusted hazard ratio (aHR): 1.22; 95 % confidence interval (CI): 1.16 to 1.28), 23 % higher risk of IHD (1.23; 1.17 to 1.31) and 19 % higher risk of stroke (1.19; 1.07 to 1.32). The percentage population-attribution risks (PAR%) were 16 % (95 % CI: 8 to 24) for CVD, 15 % (95 % CI: 6 to 24) for IHD and 18 % (95 % CI: 1 to 33) for stroke. A healthy lifestyle significantly attenuated RRS associations with the incidence of CVD and IHD. The attributable proportions due to additive interaction (p < 0.001) between RRS and HLS were 0.14 (95 % CI: 0.07 to 0.22) for CVD and 0.15 (95 % CI: 0.09 to 0.23) for IHD, respectively.

CONCLUSIONS

High RRS was associated with increased risks of CVD, IHD and stroke in female participants in the UK Biobank. The early-stage identification of women with reproductive risk using synthesised indicators and appropriate healthy lifestyle interventions could be useful for the prevention of early CVD and the extension of healthy active life expectancy.

First-trimester use of antiseizure medications and the risk of miscarriage: a population-based cohort study

BACKGROUND

Antiseizure medications (ASMs) during the first trimester of pregnancy have been associated with an increased risk of miscarriage.

METHODS

We carried out a population-based cohort study using routinely collected healthcare data from the UK, 1995-2018. Pregnancies were identified in the Clinical Practice Research Datalink and we estimated the HR of miscarriage associated with prescriptions of ASMs during the first trimester of pregnancy, using Cox regression, adjusting for potential confounders, including ASM indications.

RESULTS

ASMs were prescribed during the first trimester in 7832 (0.8%) of 1 023 787 included pregnancies. 14.5% of pregnancies with first-trimester exposure to ASMs ended in miscarriage, while 12.2% without ASM exposure in the first trimester ended in miscarriage; after adjustment, there was a 1.06-fold relative hazard of miscarriage (95% CI 1.00 to 1.13) in women with first-trimester ASM use. After restricting to women with specific ASM indications, this association was not evident in women with epilepsy (adjusted HR 0.98, 95% CI 0.89 to 1.08), but was observed in women with bipolar or other psychiatric conditions (1.08, 95% CI 1.00 to 1.16) although CIs overlapped. Compared with discontinuation of ASMs prior to pregnancy, there was no evidence of increased risk of miscarriage for first-trimester ASM use in women with bipolar or other psychiatric conditions (1.02, 95% CI 0.87 to 1.20).

CONCLUSION

We found no clear evidence to suggest that first-trimester ASM use increased the risk of miscarriage. Taken together, our analyses suggest that apparent associations between first-trimester ASM use and miscarriage may be the result of confounding by the presence of a bipolar disorder or associated unmeasured variables.

Interpregnancy Interval After Healthy Live Birth and Subsequent Spontaneous Abortion

Importance

Many studies have reported that the interpregnancy interval (IPI) is a potential modifiable risk factor for adverse perinatal outcomes. However, the association between IPI after live birth and subsequent spontaneous abortion (SA) is unclear.

Objective

To investigate the association of IPI after a healthy live birth and subsequent SA.

Design, Setting, and Participants

This prospective cohort study used data from 180 921 women aged 20 to 49 years who had a single healthy live birth and planned for another pregnancy and who participated in the Chinese National Free Prepregnancy Checkups Project from January 1, 2010, to December 31, 2020. Statistical analysis was conducted from June 20 to October 5, 2023.

Exposure

Interpregnancy interval, defined as the interval between the delivery date and conception of the subsequent pregnancy, was categorized as follows: less than 18 months, 18 to 23 months, 24 to 35 months, 36 to 59 months, and 60 months or longer.

Main Outcomes and Measures

The main outcome was SA. Multivariable-adjusted odds ratios (ORs) were calculated by logistic regression models to examine the association between IPI and the risk of SA. Dose-response associations were evaluated by restricted cubic splines.

Results

The analyses included 180 921 multiparous women (mean [SD] age at current pregnancy, 26.3 [2.8] years); 4380 SA events (2.4% of all participants) were recorded. A J-shaped association between IPI levels and SA was identified. In the fully adjusted model, compared with IPIs of 18 to 23 months, both short (<18 months) and long (≥36 months) IPIs showed an increased risk of SA (IPIs of <18 months: OR, 1.15 [95% CI, 1.04-1.27]; IPIs of 36-59 months: OR, 1.28 [95% CI, 1.15-1.43]; IPIs of ≥60 months: OR, 2.13 [95% CI, 1.78-2.56]). Results of the subgroup analysis by mode of previous delivery were consistent with the main analysis.

Conclusions and Relevance

This cohort study of multiparous women suggests that an IPI of shorter than 18 months or an IPI of 36 months or longer after a healthy live birth was associated with an increased risk of subsequent SA. The findings are valuable to make a rational prepregnancy plan and may facilitate the prevention of SA and improvement in neonatal outcomes.

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.

Relationship between male aging and semen quality: a retrospective study on over 2500 men

PURPOSE

We aimed to evaluate whether and to what extent an association exists between male aging and worsening of semen parameters and to determine whether a threshold age can be identified above which the decline in semen quality becomes statistically significant.

METHODS

2612 men (age: 16-56 years) attending an andrology outpatient clinic for semen analysis and clinical evaluation were studied. Semen analyses were performed according to the ongoing WHO-recommended procedures. Total motile count (TMC) and total progressive motile count (TPMC) were calculated by multiplying total sperm number by total motility and progressive motility, respectively.

RESULTS

Significant negative correlations were found between age and total motility (r = - 0.131, p < 0.0001), progressive motility (r = - 0.112, p < 0.0001), TPMC (r = - 0.042, p = 0.037), and normal sperm morphology (r = - 0.053, p = 0.007). All these associations persisted in multivariate regression models adjusted for abstinence time, smoking, history of male accessory gland infections, varicocele and the year in which semen analysis was performed. When comparisons were performed among quartiles of increasing age, the fourth quartile, corresponding to the age group > 40 years, was associated with a significant decrease in total and progressive motility. An earlier decline in the TPMC and percentage of normal forms was also observed.

CONCLUSION

Advancing male age exhibits an independent association with a decrease in the percentage of motile and morphologically normal spermatozoa, with greater evidence from the age of > 40 years. Further studies are warranted to elucidate the mechanisms and clinical reflections of these associations.

Influence of paternal preconception health on pregnancy, intrapartum, postpartum and early childhood outcomes: protocol for a parallel scoping review

INTRODUCTION

Preconception care is the provision of behavioural, social or biomedical interventions to women and couples prior to conception. To date, preconception research has primarily focused on maternal health, despite the male partner's contribution before birth to both short-term and long-term child outcomes. The objectives of the reviews are: (1) to identify, consolidate and analyse the literature on paternal preconception health on pregnancy and intrapartum outcomes, and (2) to identify, consolidate and analyse the literature on paternal preconception health on postpartum and early childhood outcomes.

METHODS AND ANALYSIS

A scoping review will be conducted following the Joanna Briggs Institute methodology. MEDLINE, PsycINFO, Embase, Scopus and CINAHL databases will be searched for articles published in English. Two independent reviewers will screen titles and abstracts and then full text using Covidence, with conflicts resolved by a third reviewer. Data extraction will be performed using Covidence.

ETHICS AND DISSEMINATION

Ethics approval is not required for this scoping review. Results will be published in peer-reviewed journals as well as presented at relevant national and international conferences and meetings.

Advanced Paternal Age in Focus: Unraveling Its Influence on Assisted Reproductive Technology Outcomes

As global demographics shift toward increasing paternal age, the realm of assisted reproductive technologies (ARTs), particularly in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), faces new challenges and opportunities. This study provides a comprehensive exploration of the implications of advanced paternal age on ART outcomes. Background research highlights the social, cultural, and economic factors driving men toward later fatherhood, with a focus on the impact of delayed paternity on reproductive outcomes. Methods involve a thorough review of existing literature, centering on changes in testicular function, semen quality, and genetic and epigenetic shifts associated with advancing age. Study results point to intricate associations between the father's age and ART outcomes, with older age being linked to diminished semen quality, potential genetic risks, and varied impacts on embryo quality, implantation rates, and birth outcomes. The conclusions drawn from the current study suggest that while advanced paternal age presents certain risks and challenges, understanding and mitigating these through strategies such as sperm cryopreservation, lifestyle modifications, and preimplantation genetic testing can optimize ART outcomes. Future research directions are identified to further comprehend the epigenetic mechanisms and long-term effects of the older father on offspring health. This study underscores the need for a comprehensive approach in navigating the intricacies of delayed fatherhood within the context of ART, aiming for the best possible outcomes for couples and their children.

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.

No evidence of a causal relationship between miscarriage and 25-hydroxyvitamin D: a Mendelian randomization study

STUDY QUESTION

Is there a causal relationship between 25-hydroxyvitamin D (25OHD) and miscarriage?

SUMMARY ANSWER

In this study, little evidence of a causal relationship was found between low serum 25OHD concentration or vitamin D deficiency and the risk of miscarriages.

WHAT IS KNOWN ALREADY

Associations between low vitamin D levels and increased risk of miscarriage have been reported, but causality is unclear.

STUDY DESIGN SIZE DURATION

The latest and largest genome-wide association studies (GWAS) for serum 25OHD concentration (n = 417 580), vitamin D deficiency (426 cases and 354 812 controls), miscarriage (16 906 cases and 149 622 controls), and the number of miscarriages (n = 78 700) were used to explore the causal association between serum vitamin D levels and miscarriage by two-sample Mendelian randomization analysis.

PARTICIPANTS/MATERIALS SETTING METHODS

This study was based on summary GWAS results from the FinnGen database and the UK Biobank. The random-effect inverse-variance weighted method was regarded as the primary analysis; MR-Egger, weighted median, weighted mode, simple mode, and MR-pleiotropy residual sum and outlier (MR-PRESSO) were further employed as complementary methods. MR-Egger intercept analysis and MR-PRESSO were employed to test pleiotropy, and Cochran's Q statistic and leave-one-out sensitivity analysis were used to determine the heterogeneity and robustness of the overall estimates, respectively.

MAIN RESULTS AND THE ROLE OF CHANCE

There was insufficient evidence of causal associations between serum 25OHD concentration and miscarriage (odds ratio (OR) = 0.995, 95% CI: 0.888 to 1.114, P = 0.927), or the number of miscarriages (β = -0.004, 95% CI: -0.040 to 0.032, P = 0.829). Furthermore, little evidence of causality between genetically determined vitamin D deficiency to miscarriage (OR = 0.993, 95% CI: 0.966 to 1.021, P = 0.624), or the number of miscarriages (β = 0.001, 95% CI: -0.009 to 0.011, P = 0.828), was observed. The results of the sensitivity analysis were robust, and no significant heterogeneity or horizontal pleiotropy was found.

LIMITATIONS REASONS FOR CAUTION

This study is limited by the absence of female-specific GWAS data and the limited amount of GWAS data available for this study, as well as the need for caution in generalizing the findings to non-European ethnic groups.

WIDER IMPLICATIONS OF THE FINDINGS

These findings enhance the current understanding of the intricate association between vitamin D and pregnancy outcomes, challenging prevailing beliefs regarding the strong association with miscarriage. The results provide a special perspective that may prompt further exploration and potentially offer insights for guiding future research and informing clinical guidelines pertaining to the management of miscarriage.

STUDY FUNDING/COMPETING INTERESTS

This project was supported by the Hubei Provincial Natural Science Foundation Program General Surface Project (2022CFB200), the Key Research & Developmental Program of of Hubei Province (2022BCA042), the Fundamental Research Funds for the Central Universities (2042022gf0007, 2042022kf1210), and the Interdisciplinary Innovative Talents Foundation from Renmin Hospital of Wuhan University (JCRCWL-2022-001, JCRCYG-2022-009). All authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Does Sperm SNRPN Methylation Change with Fertility Status and Age? A Systematic Review and Meta-Regression Analysis

Background: The Small Nuclear Ribonucleoprotein Polypeptide N (SNRPN) gene is a paternally expressed imprinted gene, whose abnormal methylation appears to be associated with syndromes associated with the use of assisted reproductive techniques (ART), such as Angelman and Prader-Willi. Data present in the literature suggest the association between aberrant sperm SNRPN gene methylation and abnormal sperm parameters. The latest meta-analysis on the methylation pattern of this gene in spermatozoa of infertile patients published in 2017 reported a higher degree of methylation in the spermatozoa of infertile patients compared to fertile controls. Objectives: Here we provide an updated and comprehensive systematic review and meta-analysis of the sperm methylation pattern of the SNRPN gene in patients with abnormal sperm parameters/infertility compared to men with normal sperm parameters/fertile. For the first time in the literature, we performed a meta-regression analysis to evaluate whether age or sperm concentration could influence the methylation status of this gene at the sperm level. Methods: This meta-analysis was registered in PROSPERO (n. CRD42023397056). The Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) and the MOOSE guidelines for meta-analyses and systematic reviews of observational studies were strictly followed in our meta-analysis. According to our Population Exposure Comparison Outcome (PECO) question, we included data from original articles assessing the levels of SNRPN gene methylation at the sperm level in infertile patients or patients with abnormalities in one or more sperm parameters compared to fertile or normozoospermic men. Results: Only six of 354 screened studies were included in the quantitative synthesis. Our analysis showed significantly higher levels of SNRPN gene methylation in patients compared to controls. However, significant heterogeneity was found between studies. In sensitivity analysis, no studies were sensitive enough to skew the results. The Egger test showed no publication bias. In the meta-regression analysis, the results were independent of age and sperm concentration in the overall population. The same results were found in the control group. However, when analyzing the patient group, a direct correlation was found between SNRPN methylation and age, indicating that the degree of methylation of the SNRPN gene increases with advancing age. Conclusions: Fertility status or abnormality of sperm parameters is associated with a change in the methylation pattern of the SNRPN gene, with higher levels found in infertile patients or those with abnormal sperm parameters compared to fertile men or men with normal sperm parameters. In the group of infertile patients/patients with abnormal sperm parameters, age was directly correlated to the degree of SNRPN methylation, highlighting the presence of a mechanism that explains the age-related altered sperm quality and the risk of ART. Despite some limitations present in the analyzed studies, our results support the inclusion of SNRPN methylation in the genetic panel of prospective studies aimed at identifying the most representative and cost-effective genes to analyze in couples who want to undergo ART.

Development and validation of a visualized prediction model for early miscarriage risk in patients undergoing IVF/ICSI procedures: a real-world multi-center study

Background

This study focuses on the risk of early miscarriage in patients undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). These patients commonly experience heightened stress levels and may discontinue treatment due to emotional burdens associated with repeated failures. Despite the identification of numerous potential factors contributing to early miscarriage, there exists a research gap in integrating these factors into predictive models specifically for IVF/ICSI patients. The objective of this study is to develop a user-friendly nomogram that incorporates relevant risk factors to predict early miscarriage in IVF/ICSI patients. Through internal and external validation, the nomogram facilitates early identification of high-risk patients, supporting clinicians in making informed decisions.

Methods

A retrospective analysis was conducted on 20,322 first cycles out of 31,307 for IVF/ICSI treatment at Sun Yat-sen Memorial Hospital between January 2011 and December 2020. After excluding ineligible cycles, 6,724 first fresh cycles were included and randomly divided into a training dataset (n = 4,516) and an internal validation dataset (n = 2,208). An external dataset (n = 1,179) from another hospital was used for validation. Logistic and LASSO regression models identified risk factors, and a multivariable logistic regression constructed the nomogram. Model performance was evaluated using AUC, calibration curves, and decision curve analysis (DCA).

Results

Significant risk factors for early miscarriage were identified, including female age, BMI, number of spontaneous abortions, number of induced abortions and medical abortions, basal FSH levels, endometrial thickness on hCG day, and number of good quality embryos. The predictive nomogram demonstrated good fit and discriminatory power, with AUC values of 0.660, 0.640, and 0.615 for the training, internal validation, and external validation datasets, respectively. Calibration curves showed good consistency with actual outcomes, and DCA confirmed the clinical usefulness. Subgroup analysis revealed variations; for the elder subgroup (age ≥35 years), female age, basal FSH levels, and number of available embryos were significant risk factors, while for the younger subgroup (age <35 years), female age, BMI, number of spontaneous abortions, and number of good quality embryos were significant.

Conclusions

Our study provides valuable insights into the impact factors of early miscarriage in both the general study population and specific age subgroups, offering practical recommendations for clinical practitioners. We have taken into account the significance of population differences and regional variations, ensuring the adaptability and relevance of our model across diverse populations. The user-friendly visualization of results and subgroup analysis further enhance the applicability and value of our research. These findings have significant implications for informed decision-making, allowing for individualized treatment strategies and the optimization of outcomes in IVF/ICSI patients.

Women's reproductive risk and genetic predisposition in type 2 diabetes: A prospective cohort study

OBJECTIVE

To assess synergistic effects of reproductive factors and gene-reproductive interaction on type 2 diabetes (T2D) risk, also the extent to which the genetic risk of T2D can be affected by reproductive risk.

METHODS

84,254 women with genetic data and reproductive factors were enrolled between 2006 and 2010 in the UK Biobank. The reproductive risk score (RRS) was conducted based on 17 reproductive items, and genetic risk score (GRS) was based on 149 genetic variants.

RESULTS

There were 2300 (2.8 %) T2D cases during an average follow-up of 4.49 years. We found a significant increase in T2D risk across RRS categories (Ptrend < 0.001). Compared with low reproductive risk, high-mediate (adjusted hazard ratio [aHR] 1.38, 95 % CI 1.20-1.58) and high (aHR 1.84, 95 % CI 1.54-2.19) reproductive risk could increase the risk of T2D. We further observed a significant additive interaction between reproductive risk and genetic predisposition. In the situation of high genetic predisposition, women with low reproductive risk had lower risk of T2D than those with high reproductive risk (aHR 0.47, 95 % CI 0.30-0.76), with an absolute risk reduction of 2.98 %.

CONCLUSIONS

Our novo developed RRS identified high reproductive risk is associated with elevated risk of women's T2D, which can be magnified by gene-reproductive interaction.

Paternal age and perinatal outcomes: an observational study

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Leptin and Leptin Receptor Polymorphisms in Infants and Their Parents: Correlation with Preterm Birth

It has been proven that single-nucleotide polymorphisms (SNPs) in LEP and LEPR genes could predispose individuals to an increased risk of pregnancy adverse outcomes (PAOs) such as recurrent pregnancy loss (RPL) and pre-eclampsia. Preterm birth (PTB) is the leading cause of infant mortality. We decided to investigate the correlation between PTB and LEP and LEPR SNPs. The study cohort included families who underwent spontaneous PTB and control samples of families who had at-term-born (≥37 weeks of gestational age) children. Swabs were performed by rubbing the sticky end for about 30 s on the gum and on the inside of the cheek, allowing us to collect the flaking cells of the oral mucosa. Genotyping of the three SNPs-LEPRA668G, LEPG2548A and A19G-was carried out via an ARMS-MAMA real-time PCR procedure, as previously described. Regarding LEPG2548A, we found that the most expressed genotype in infants both in the preterm and the at-term group was AG; however, we did not discover any statistically significant difference (p = 0.97). Considering LEPA19G, none among the infants and parents were found to carry the AA genotype. No statistically significant differences were found between children, mothers and fathers belonging to preterm and at-term groups. We did not find a statistically significant association in newborns and their mother, but our results show a statistical correlation with the LEPRA668G genotype GG of the father. This fact can contribute to defining genetic risk factors for PTB. Further studies are certainly needed to better clarify the role of genetics in influencing preterm delivery.