Di(2-ethylhexyl) phthalate induces reproductive toxicity and transgenerational reproductive aging in Caenorhabditis elegans

With the large-scale production and use of plastic products, the global plastic pollution problem is becoming more and more serious. The plasticizer di (2-ethylhexyl) phthalate (DEHP), which is widely used in the production of plastics, has caused great concern for the health of the population. Exposure of organisms to DEHP can cause a variety of health damage, of which reproductive system damage is an important part. At present, there are still few studies on DEHP in reproductive aging, and it is of great significance to explore the role of DEHP in promoting reproductive aging and its underlying mechanism. In this study, the model organism Caenorhabditis elegans (C. elegans) was used to preliminarily explore the mechanism of DEHP-induced female reproductive senescence. The results showed that DEHP reduced the number of offspring and gonad area of C. elegans, resulting in shortened reproductive and life span, abnormal phenotypes in somatic gonad structure including the Emo phenotype, the BOW phenotype, a twisted gonad arm, and atrophied oocytes. Biochemical studies showed that DEHP promoted oxidative stress and autophagy in C. elegans. Further, we found the decreased number of offspring, malformed somatic gonad structure, oxidative damage and autophagy induced by DEHP in parental worms can be inheritance to the not directly exposed offspring.

PGT-A improved singleton live birth rate among all age groups of women who underwent elective single blastocyst transfer: a single-centre retrospective study

PURPOSE

This study assessed the difference in singleton live birth rate (SLBR) between preimplantation genetic testing for aneuploidy (PGT-A) and non-PGT in patients undergoing elective single frozen blastocyst transfer (eSFBT).

METHODS

This retrospective cohort study evaluated 10,701 cycles of eSFBT, including PGT-A (n = 3125) and non-PGT (n = 7576). Cycles were further stratified according to age at retrieval. The main outcome was SLBR; secondary outcomes were clinical pregnancy, conception rates, and multiple live birth rate. Confounders were adjusted using multivariable logistic regression models, and the trend test was performed using the general linear model.

RESULTS

SLBR was negatively correlated with age in the non-PGT group (p-trend < 0.001) but not in PGT-A group (p-trend = 0.974). Stratified by the age, SLBR were significantly different between two groups except for the 20-24-year-old group: PGT-A vs non-PGT group in 20-24, 25-29, 30-34, 35-39 and ≥ 40-year-old subgroups were, 53.5% vs 53.2%, 53.5% vs 48.0%, 53.5% vs 43.1%, 53.3% vs 32.5%, and 42.9% vs 17.6%, respectively. In addition, after adjusting for potential confounders, SLBR still remained significantly different in all age groups except in the youngest quartile (PGT-A vs non-PGT group, 20-24: adjusted odds ratio (aOR), 1.33, 95% CI, 0.92-1.92, p = 0.129; 25-29: aOR, 1.32, 95% CI, 1.14-1.52, p < 0.001; 30-34: aOR, 1.91, 95% CI, 1.65-2.20, p < 0.001; 35-39: aOR, 2.50, 95% CI, 1.97-3.17, p < 0.001; ≥ 40: aOR, 3.54, 95% CI, 1.66-7.55, p = 0.001).

CONCLUSION

PGT-A might improve SLBR among all age groups and play an increasingly important role in SLBR in older patients who underwent eSFBT.

Awareness and perceptions of Filipino obstetrician-gynecologists on fertility preservation: a cross-sectional survey

BACKGROUND

The demand for fertility preservation has increased substantially over the past decade as more women wish to delay childbearing and with improved survival outcomes of various medical conditions. This study evaluated the awareness and perceptions of Filipino obstetrician-gynecologists on fertility preservation.

METHODS

A cross-sectional survey was conducted among diplomates and fellows of the Philippine Obstetrical and Gynecological Society from September to December 2021. A self-administered questionnaire with 24 items was distributed online. Univariate descriptive statistics were reported as means for continuous variables and frequencies with percentage for categorical variables. Differences in responses were tested using the chi-square test.

RESULTS

A total of 215 respondents completed the survey. Majority of the respondents were female, general obstetrician-gynecologists practicing in the National Capital Region. There was an overall positive perception of fertility preservation, with 98.60% agreeing that discussions about childbearing intentions should be initiated. Most participants (98.60%) were aware of fertility preservation but had varying levels of awareness of the different techniques. Fifty-nine percent of the respondents were unaware of regulations on fertility preservation. Setting up dedicated centers for fertility preservation and offering it as a public service were viewed as necessary by the respondents.

CONCLUSIONS

This study underscored the need to increase awareness of fertility preservation techniques among Filipino obstetrician-gynecologists. Meeting the need for comprehensive guidelines and centers is essential to promote fertility preservation in the country. Efficient referral systems and multidisciplinary approaches should be established for holistic care.

Single-cell RNA sequencing reveals the local cell landscape in mouse epididymal initial segment during aging

BACKGROUND

Morphological and functional alterations in aging reproductive organs result in decreased male fertility. The epididymis functions as the transition region for post-testicular sperm maturation. And we have previously demonstrated that the epididymal initial segment (IS), a region of the reproductive tract essential for sperm maturation and capacitation, undergoes considerable histological changes and chronic immune activation in mice during aging. However, the local aging-associated cellular and molecular changes in the aged epididymal IS are poorly understood.

RESULTS

We conducted single-cell RNA sequencing analysis on the epididymal IS of young (3-month-old) and old (21-month-old) mice. In total, 10,027 cells from the epididymal IS tissues of young and old mice were obtained and annotated. The cell composition, including the expansion of a principal cell subtype and Ms4a4b^HiMs4a6b^Hi T cells, changed with age. Aged principal cells displayed multiple functional gene expression changes associated with acrosome reaction and sperm maturation, suggesting an asynchronous process of sperm activation and maturation during epididymal transit. Meanwhile, aging-related altered pathways in immune cells, especially the "cell chemotaxis" in Cx3cr1^Hi epididymal dendritic cells (eDCs), were identified. The monocyte-specific expression of chemokine Ccl8 increased with age in eDCs. And the aged epididymal IS showed increased inflammatory cell infiltration and cytokine secretion. Furthermore, cell-cell communication analysis indicated that age increased inflammatory signaling in the epididymal IS.

CONCLUSION

Contrary to the general pattern of lower immune responses in the male proximal genital tract, we revealed an inflammaging status in mouse epididymal initial segment. These findings will allow future studies to enable the delay of male reproductive aging via immune regulation.

Morphokinetic parameters of mouse oocyte meiotic maturation and cumulus expansion are not affected by reproductive age or ploidy status

INTRODUCTION

Morphokinetic analysis using a closed time-lapse monitoring system (EmbryoScope + ™) provides quantitative metrics of meiotic progression and cumulus expansion. The goal of this study was to use a physiologic aging mouse model, in which egg aneuploidy levels increase, to determine whether there are age-dependent differences in morphokinetic parameters of oocyte maturation.

METHODS

Denuded oocytes and intact cumulus-oocyte complexes (COCs) were isolated from reproductively young and old mice and in vitro matured in the EmbryoScope + ™. Morphokinetic parameters of meiotic progression and cumulus expansion were evaluated, compared between reproductively young and old mice, and correlated with egg ploidy status.

RESULTS

Oocytes from reproductively old mice were smaller than young counterparts in terms of GV area (446.42 ± 4.15 vs. 416.79 ± 5.24 µm2, p < 0.0001) and oocyte area (4195.71 ± 33.10 vs. 4081.62 ± 41.04 µm2, p < 0.05). In addition, the aneuploidy incidence was higher in eggs with advanced reproductive age (24-27% vs. 8-9%, p < 0.05). There were no differences in the morphokinetic parameters of oocyte maturation between oocytes from reproductively young and old mice with respect to time to germinal vesicle breakdown (GVBD) (1.03 ± 0.03 vs. 1.01 ± 0.04 h), polar body extrusion (PBE) (8.56 ± 0.11 vs. 8.52 ± 0.15 h), duration of meiosis I (7.58 ± 0.10 vs. 7.48 ± 0.11 h), and kinetics of cumulus expansion (0.093 ± 0.002 vs. 0.089 ± 0.003 µm/min). All morphokinetic parameters of oocyte maturation were similar between euploid and aneuploid eggs irrespective of age.

CONCLUSION

There is no association between age or ploidy and the morphokinetics of mouse oocyte in vitro maturation (IVM). Future studies are needed to evaluate whether there is an association between morphokinetic dynamics of mouse IVM and embryo developmental competence.

Reproductive aging: biological pathways and potential interventive strategies

Reproductive aging is a natural process conserved across species and is well-known in females. It shows age-related follicle depletion and reduction of oocyte quality, eventually causing reproductive senescence and menopause. Although reproductive aging in males is not well noticed as in females, it also causes infertility and has deleterious consequences on the offspring. Various factors have been suggested to contribute to reproductive aging, including oxidative stress, mitochondrial defects, telomere shortening, meiotic chromosome segregation errors and genetic alterations. With the increasing trend of pregnancy age, it is particularly crucial to find interventions to preserve or extend human fertility. Studies in humans and model organisms have provided insights into the biological pathways associated with reproductive aging, and a series of potential interventive strategies have been tested. Here, we review factors affecting reproductive aging in females and males and summarize interventive strategies that may help delay or rescue the aging phenotypes of reproduction.

The medieval biological clock? Gendered reproductive aging in medieval western medicine

This paper examines discussions of women's and men's reproductive aging in a series of western European medical texts written in the period 1100-1300. It uses the modern image of the biological clock to explore how far physicians in earlier periods understood reproductive aging to be a process of slow decline before a final age at which fertility ended (menopause for women, or a less defined 'old age' for men), and how far they viewed women's reproductive aging as different from men's. The article argues that, in contrast to modern medical and popular understandings, medieval physicians assumed men and women were broadly fertile up to a final cut-off point, and had little interest in viewing age-related fertility decline as a slow process beginning well before menopause. This was true in part because there was no realistic prospect of treatment for age-related reproductive disorders. The article also argues that in many respects - although not all - medieval writers viewed men's and women's reproductive aging as similar processes. Overall the model of reproductive aging they offered was flexible and offered room for individual variation. In this way the article demonstrates how changing understandings of the body, reproduction, and aging, demographic and social change, and changing medical treatments influence concepts of reproductive aging.

Intermittent fasting reverses the declining quality of aged oocytes

Decreased oocyte quality and compromised embryo development are particularly prevalent in older females, but the aging-related cellular processes and effective ameliorative approaches have not been fully characterized. Intermittent fasting (IF) can help improve health and extend lifespan; nevertheless, how it regulates reproductive aging and its mechanisms remain unclear. We used naturally aged mice to investigate the role of IF in reproduction and found that just one month of every-other-day fasting was sufficient to improve oocyte quality. IF not only increased antral follicle numbers and ovulation but also enhanced oocyte meiotic competence and embryonic development by improving both nuclear and cytoplasmic maturation in maternally aged oocytes. The beneficial effects of IF manifested as alleviation of spindle structure abnormalities and chromosome segregation errors and maintenance of the correct cytoplasmic organelle reorganization. Moreover, single-cell transcriptome analysis showed that the positive impact of IF on aged oocytes was mediated by restoration of the nicotinamide adenine dinucleotide (NAD+)/Sirt1-mediated antioxidant defense system, which eliminated excessive accumulated ROS to suppress DNA damage and apoptosis. Collectively, these findings suggest that IF is a feasible approach to protect oocytes against advanced maternal age-related oxidation damage and to improve the reproductive outcomes of aged females.

C. elegans as a model organism to study female reproductive health

Female reproductive health has been historically understudied and underfunded. Here, we present the advantages of using a free-living nematode, Caenorhabditis elegans, as an animal system to study fundamental aspects of female reproductive health. C. elegans is a powerful high-throughput model organism that shares key genetic and physiological similarities with humans. In this review, we highlight areas of pressing medical and biological importance in the 21st century within the context of female reproductive health. These include the decline in female reproductive capacity with increasing chronological age, reproductive dysfunction arising from toxic environmental insults, and cancers of the reproductive system. C. elegans has been instrumental in uncovering mechanistic insights underlying these processes, and has been valuable for developing and testing therapeutics to combat them. Adopting a convenient model organism such as C. elegans for studying reproductive health will encourage further research into this field, and broaden opportunities for making advancements into evolutionarily conserved mechanisms that control reproductive function.

Down-regulation of long non-coding RNAs in reproductive aging and analysis of the lncRNA-miRNA-mRNA networks in human cumulus cells

PURPOSE

Long non-coding RNAs (lncRNAs) control gene expression at multiple levels. By interacting with microRNAs (miRNAs), they regulate their mRNA targets creating dynamic regulatory networks involved in different cellular processes. Their role in follicle development and oocyte maturation has recently emerged. lncRNA deregulation has been found associated with different pathological conditions. In this study, we identified differentially expressed lncRNAs in cumulus cells (CCs) isolated from MII oocytes of advanced maternal age women and proposed ceRNA-networks involved in signaling pathways crucial in ovarian folliculogenesis and female germ cell maturation.

METHODS

We performed a high-throughput analysis of the expression profile of 68 lncRNAs from CCs of aged and young women by using NanoString technology. By miRNet, TarPmiR, miRTarBase, OKdb, and KEGG we predicted some ceRNA-networks involving the differentially expressed (DE) lncRNAs, miRNA interactors, and their mRNA target genes.

RESULTS

We identified 28 lncRNAs down-regulated in CC samples from aged women. The analysis revealed that the miRNAs binding 11 of the DE lncRNAs and their mRNA targets are included in ceRNA-networks involved in the regulation of the PI3K-Akt, FOXO, and p53 signaling pathways.

CONCLUSION

We proposed that the lncRNA down-regulation in CCs from aged women could influence the expression of genes encoding proteins deregulated in reproductive aging. A better understanding of the interplay of lncRNA-miRNA-mRNA networks in human CCs could increase our knowledge about the mechanisms of regulation of gene expression involved in aging, lead to the development of novel therapeutics, and improve reproductive outcomes in aged women.

Late fertility intentions increase over time in Austria, but chances to have a child at later ages remain low

Childbearing takes place at increasingly older ages, and fertility is continuing to decrease across female birth cohorts. This study investigated whether the proportion of women who unintentionally forwent childbearing increased over time, and linked this to the age profile of fertility intentions and realization among men and women. This study was based on the Austrian Micro-Censuses (1986-2016) and on the Austrian Generations and Gender Surveys (panel data 2008/09 and 2012/13). Across the birth cohorts 1950-1979, an increasing proportion of women wanted to have children after 40 years of age, but more women failed to meet their fertility intentions expressed at 34-36 years of age. At the individual level, from 30 years of age, more than one-third of women and men with a strong fertility intention were found to persist with this intention within four years even at less fertile ages. In addition, women and men with a strong fertility intention became less likely to have a child with age: <10% of women and approximately 20% of men who had expressed a certain and short-term intention to have a child at 39-41 years of age in 2008/09 had a child by 2012/13. In particular, childless women and men, and those with only one child, persisted in certain and short-term positive intentions from 30 years of age, but parity was not a significant factor in their realization. The sharp increase in 'unrealized fertility' over time draws attention to the importance that personal circumstances and context encountered at older ages may have for fertility, and augurs a continued increase in the use of assisted reproduction.

Oocyte aging: looking beyond chromosome segregation errors

The age-associated decline in female fertility is largely ascribable to a decrease in oocyte quality. This phenomenon is multifaceted and influenced by numerous interconnected maternal and environmental factors. An increase in the rate of meiotic errors is the major cause of the decline in oocyte developmental competence. However, abnormalities in the ooplasm accumulating with age - including altered metabolism, organelle dysfunction, and aberrant gene regulation - progressively undermine oocyte quality. Stockpiling of maternal macromolecules during folliculogenesis is crucial, as oocyte competence to achieve maturation, fertilization, and the earliest phases of embryo development occur in absence of transcription. At the same time, crucial remodeling of oocyte epigenetics during oogenesis is potentially exposed to interfering factors, such as assisted reproduction technologies (ARTs) or environmental changes, whose impact may be enhanced by reproductive aging. As the effects of maternal aging on molecular mechanisms governing the function of the human oocyte remain poorly understood, studies in animal models are essential to deepen current understanding, with translational implications for human ARTs. The present mini review aims at offering an updated and consistent view of cytoplasmic alterations occurring in oocytes during aging, focusing particularly on gene and epigenetic regulation. Appreciation of these mechanisms could inspire solutions to mitigate/control the phenomenon, and thus benefit modern ARTs.

Ethylbenzene exposure disrupts ovarian function in Wistar rats via altering folliculogenesis and steroidogenesis-related markers and activating autophagy and apoptosis

Ethylbenzene is a hydrocarbon that is extensively used in both industry and in the home and has been reported as toxic to various tissues. Nevertheless, its effect on ovarian function remains unclear. For this purpose, we assessed ovarian tissue morphology, evaluated protein and gene expression related to folliculogenesis and steroidogenesis, and investigated the involvement of both apoptosis and autophagy processes in this effect. Female Wistar albinos rats were treated with 2000, 4000 and 8000 ppm doses of ethylbenzene by inhalation for 30 min daily for one month. Ovaries were then removed and proceeded for histopathological and molecular analyses. We found that ethylbenzene affected folliculogenesis by decreasing the number of growing follicles and increasing the number of abnormal follicles, leading to faster female reproductive aging. Interestingly, it disrupted female reproductive hormone balance, including progesterone, estradiol, testosterone and IGF-1 plasma levels. The latter protein, along with GDF-9, significantly decreased in all ethylbenzene-treated groups, leading to the disruption of follicular cell proliferation and development. TUNEL assay study showed that ethylbenzene exposure significantly increased the number of apoptotic cells. The mRNA levels of genes involved in granulosa cell proliferation and differentiation, such as INSL3, CCND2 and ACTB, were significantly decreased. In addition, LC3 protein expression increased, and its encoding gene was upregulated, suggesting that ethylbenzene treatment induced autophagy. In summary, ethylbenzene exposure caused structural and functional disorders of the ovary by disrupting the normal growth of follicles, altering reproductive hormone balance, inhibiting the expression of key reproductive proteins and triggering autophagy as well as apoptosis.

Ultraviolet radiation and age at natural menopause in a nationwide, prospective US cohort

BACKGROUND

Solar ultraviolet radiation (UV) is a critical environmental factor for dermal conversion of vitamin D, which is suggested to support reproductive health. However, current epidemiological studies have reported conflicting results on the associations between vitamin D levels and ovarian reserve. Further, few studies have considered UV exposure and reproductive aging, which is closely related to declined ovarian reserve.

OBJECTIVES

We sought to examine the associations of long-term UV exposure and age at natural menopause in a large, nationwide, prospective cohort.

METHODS

Participants in the Nurses' Health Study II (NHS II) who were premenopausal at age 40 were included and followed through 2015. Erythemal UV radiation from a high-resolution geospatial model was linked to the participants' residential histories. Early-life UV was estimated using the reported state of residence at birth, age 15, and age 30. We used time-varying Cox proportional hazards models to estimate the hazard ratio (HR) and 95% confidence intervals (CIs) for natural menopause, adjusting for potential confounders and predictors of menopause.

RESULTS

A total of 63,801 women reported natural menopause across the 1,051,185 person-years of follow-up among 105,631 eligible participants. We found very modest associations with delayed menopause for long-term UV exposure (adjusted HR comparing highest to lowest quartile of cumulative average UV: 0.96, 95% CI: 0.94, 0.99). There was a suggestive inverse association between UV at age 30 with menopause (adjusted HR comparing highest to lowest quartile: 0.97, 95% CI: 0.95, 1.00) but not with UV at birth and age 15.

CONCLUSIONS

Solar UV exposure in adulthood was modestly associated with later onset of menopause. Although consistent with previous findings on vitamin D intake and menopause in the same population, these weak associations found in this study may not be of clinical relevance.

Melatonin improves the quality of maternally aged oocytes by maintaining intercellular communication and antioxidant metabolite supply

In mammalian ovaries, oocytes are physically coupled to somatic granulosa cells, and this coupling is crucial for the growth and development of competent oocytes as it mediates the transfer of metabolic support molecules. However, aging-mediated dysregulation in communication between the oocytes and granulosa cells affects the oocyte quality. In the present study, we examined the defected germline-soma communication and reduced mRNA levels encoding key structural components of transzonal projections (TZPs) in maternally aged oocytes. Oral administration of melatonin to aged mice substantially increased TZPs and maintained the cumulus cells-oocyte communication, which played a central role in the production of adequate oocyte ATP levels and reducing the accumulation of reactive oxygen species (ROS), apoptosis, DNA damage, endoplasmic reticulum (ER) stress and spindle/chromosomal defects. This beneficial effect of melatonin was inhibited by carbenoxolone (CBX), a gap junctional uncoupler, which disrupts bidirectional communications between oocyte and somatic cells. Simultaneously, melatonin significantly increased the mRNA and protein levels corresponding to genes associated with TZPs and prevented TZP retraction in in vitro-cultured cumulus-oocyte complex (COCs). Furthermore, we infused melatonin and CBX into the COCs in vitro culture system and monitored the levels of nicotinamide adenine dinucleotide phosphate (NADPH) and glutathione (GSH) in cumulus cells and oocytes. Notably, COCs treated with melatonin demonstrated improved NADPH and GSH levels. Of note, CBX was capable of reducing NADPH and GSH levels, aggravated the ROS accumulation and ER stress. Collectively, our data demonstrate the role of melatonin in preventing age-associated germline-soma communication defects, aiding the relay of antioxidant metabolic molecules for the maintenance of oocyte quality from cumulus cells, which have important potential for improving deficient phenotypes of maternally aged oocytes and the treatment of woman infertility.

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Communication between the oocytes and cumulus cells declines with age.

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Melatonin repair of aging-induced dysregulation in communication between the oocytes and cumulus cells.

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Melatonin preventing age-associated metabolic co-dependence defects of oocytes and cumulus cells.

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Melatonin attenuates mitochondrial dysfunction and endoplasmic reticulum stress.

Childhood lung function as a determinant of menopause-dependent lung function decline

RATIONALE

The naturally occurring age-dependent decline in lung function accelerates after menopause, likely due to the change of the endocrine balance. Although increasing evidence shows suboptimal lung health in early life can increase adult  susceptibility to insults, the potential effect of poor childhood lung function on menopause-dependent lung function decline has not yet been investigated.

OBJECTIVES

To study whether menopause-dependent lung function decline, assessed as forced vital capacity (FVC) and forced expiratory volume in one second (FEV1), is determined by childhood lung function.

METHODS

The Tasmanian Longitudinal Health Study, a cohort born in 1961, underwent spirometry at age seven.  At ages 45 and 50 serum samples, spirometry and questionnaire data were collected (N = 506). We measured follicle stimulating and luteinizing hormones to determine menopausal status using latent profile analysis. The menopause-dependent lung function decline was investigated using linear mixed models, adjusted for anthropometrics, occupational level, smoking, asthma, asthma medication and study year, for the whole study population and stratified by tertiles of childhood lung function.

MEASUREMENTS AND MAIN RESULTS

The overall menopause-dependent lung function decline was 19.3 mL/y (95%CI 2.2 to 36.3) for FVC and 9.1 mL/y (-2.8 to 21.0) for FEV1. This was most pronounced (pinteraction=0.03) among women within the lowest tertile of childhood lung function [FVC 22.2 mL/y (1.1 to 43.4); FEV1 13.9 mL/y (-1.5 to 29.4)].

CONCLUSIONS

Lung function declines especially rapidly in postmenopausal women who had poor low lung function in childhood. This provides novel insights into respiratory health during reproductive aging and emphasizes the need for holistic public health strategies covering the whole lifespan.

Predictive value of anti-Müllerian hormone on pregnancy outcomes in in-vitro fertilization/intracytoplasmic single sperm injection patients at different ages

PURPOSE

To investigate the predictive value of AMH level for pregnancy outcomes in different age groups of IVF/ICSI patients.

METHODS

The study was a cohort study that included 11,484 patients that had their first IVF/ICSI procedure between 2016 and 2019. All patients who met the inclusion and exclusion criteria were divided into 6 groups according to 5-year age intervals, namely, Group 1: 20-24 years (n = 725); Group 2: 25-29 years (n = 4019); Group 3: 30-34 years (n = 3600); Group 4: 35-39 years (n = 1915); Group 5: 40-44 years (n = 1006); and Group 6: ≥ 45 years (n = 219).

RESULTS

Receiver operating characteristic (ROC) curve analysis revealed that AMH level could only predict the outcome of live birth in Group 3 and Group 4 (p < 0.05). The area under the curve (AUC) of Group 3 was 0.536 (95% CI 0.510-0.561, p = 0.006), and that of Group 4 was 0.562 (95% CI 0.527-0.598, p = 0.001). The cutoff values of AMH for predicting live birth in Group 3 and Group 4 were 1.84 ng/ml and 1.86 ng/ml, respectively. Further logistic regression analysis showed that only the cutoff values of AMH and age could predict live birth in Groups 3 and 4.

CONCLUSIONS

AMH level could predict live birth in IVF/ICSI patients at the age of 30-39. However, it could not be used to predict live birth in patients < 30 years or ≥ 40 years.

Associations of long-term exposure to environmental noise and outdoor light at night with age at natural menopause in a US women cohort

Previous studies have suggested noise, especially at night time, and light at night (LAN) could cause neuroendocrine disturbance and circadian disruption, which may lead to ovarian follicle atresia and earlier onset of menopause. However, no study to date has directly investigated the associations of exposure to these factors and menopausal age.

Methods

Premenopausal women from the Nurses' Health Study II (NHS II) were followed from age 40 through 2015. Median daytime and nighttime anthropogenic noise and outdoor LAN exposure were measured from a geospatial prediction model and satellite images, respectively, at residential addresses throughout the follow-up. Time-varying Cox proportional hazard models were used to calculate the hazard ratios and 95% confidence intervals, adjusting for individual lifestyle, reproductive history, and neighborhood socioeconomic factors. Possible effect modification by region, smoking status, body mass index, race/ethnicity, history of rotating shift work, and census tract population density and median income was examined.

Results

A total of 63,380 of 105,326 women self-reported natural menopause during 1,043,298 person-years of follow-up. No associations were found for noise (both daytime and nighttime) and outdoor LAN exposure with age at natural menopause (hazard ratios = 0.99-1.00) in the fully adjusted models. Sensitivity analyses showed similar null associations. No meaningful effect modification was found for region, smoking status, body mass index, race/ethnicity, history of rotating shift work, and census tract socioeconomic measures in stratified analyses.

Conclusion

No associations were found between environmental noise and outdoor LAN exposure in mid-adulthood and menopausal age in this cohort of US women.

Associations of age at natural menopause and occupations in Chinese female workers: A cross-sectional study

AIMS

To investigate the impact of occupation types on age at natural menopause.

METHODS

This is a nation-wide cross-sectional study based on 17,948 female workers aged over 40, who come from different industries or organizations. A face-to-face standardized questionnaire was conducted in all participants with the help of occupational hygienists. Occupational titles were coded according to the International Standard Classification of Occupations (2008) (ISCO08). Cox regression model was used to assess the association between each independent occupation and menopausal timing. Models were adjusted for marriage, education, average annual family income, parity, cigarette smoking, alcohol consumption.

RESULTS

Higher risks of earlier age at natural menopause was found among legislators and senior officials (ISCO Minor group:111, HR = 2.328, P < 0.001), among other health associated professionals (ISCO Minor group: 325, HR = 1.477, P = 0.003), the workers involved in mining and mineral processing (ISCO Minor group: 811, HR = 1.515, P = 0.048) and metal processing and finishing (ISCO Minor group: 812, HR = 1.722, P < 0.001). Reduced risks of earlier age at natural menopause, including: finance professionals (ISCO Minor group: 241, HR = 0.751, P = 0.021), manufacturing and construction supervisors (ISCO Minor group: 312, HR = 0.477, P = 0.002), administrative and specialized secretaries (ISCO Minor group: 334, HR = 0.788, P = 0.045), cleaners and helpers (ISCO Minor group: 911, HR = 0.633, P = 0.01).

CONCLUSIONS

This is the first study to address the influence of occupation types on reproductive aging, showing some specific occupations could be associated with age at natural menopause. Further investigations are necessary to clarify whether it is chance finding or a true association.

Long-term exposure to particulate matter and roadway proximity with age at natural menopause in the Nurses' Health Study II Cohort

Evidence has shown associations between air pollution and traffic-related exposure with accelerated aging, but no study to date has linked the exposure with age at natural menopause, an important indicator of reproductive aging. In this study, we sought to examine the associations of residential exposure to ambient particulate matter (PM) and distance to major roadways with age at natural menopause in the Nurses' Health Study II (NHS II), a large, prospective female cohort in US. A total of 105,996 premenopausal participants in NHS II were included at age 40 and followed through 2015. Time-varying residential exposures to PM10, PM2.5-10, and PM2.5 and distance to roads was estimated. We calculated hazard ratios (HR) and 95% confidence intervals (CIs) for natural menopause using Cox proportional hazard models adjusting for potential confounders and predictors of age at menopause. We also examined effect modification by region, smoking, body mass, physical activity, menstrual cycle length, and population density. There were 64,340 reports of natural menopause throughout 1,059,229 person-years of follow-up. In fully adjusted models, a 10 μg/m3 increase in the cumulative average exposure to PM10 (HR: 1.02, 95% CI: 1.00, 1.04), PM2.5-10 (HR: 1.03, 95% CI: 1.00, 1.05), and PM2.5 (HR: 1.03, 95% CI: 1.00, 1.06) and living within 50 m to a major road at age 40 (HR: 1.03, 95%CI: 1.00, 1.06) were associated with slightly earlier menopause. No statistically significant effect modification was found, although the associations of PM were slightly stronger for women who lived in the West and for never smokers. To conclude, we found exposure to ambient PM and traffic in midlife was associated with slightly earlier onset of natural menopause. Our results support previous evidence that exposure to air pollution and traffic may accelerate reproductive aging.

Ultraviolet radiation as a predictor of sex hormone levels in postmenopausal women: A European multi-center study (ECRHS)

BACKGROUND

Solar ultraviolet radiation (UVR) affects the body through pathways that exhibit positive as well as negative health effects such as immunoregulation and vitamin D production. Different vitamin D metabolites are associated with higher or lower concentrations of estrogens and may thus alter the female sex hormone balance.

OBJECTIVE

To study whether exposure to UVR, as a modifiable lifestyle factor, is associated with levels of sex hormones (17β-estradiol, estrone, estrone 3-sulfate, testosterone, dehydroepiandrosterone sulfate), gonadotropins (follicle stimulating hormone, luteinizing hormone) as well as sex hormone binding globulin in postmenopausal women, and thus investigate whether managing UVR exposure can influence the hormone balance, with potential benefits for the biological aging process.

METHODS

The study included 580 postmenopausal women from six European countries, participating in the European Community Respiratory Health Survey (2010-2014). Average UVR exposure during the month before blood sampling was estimated based on personal sun behavior and ambient levels. Hormone concentrations were measured in serum using state-of-the-art methods. Subsequently we applied linear mixed-effects models, including center as random intercept, hormone concentrations (one at a time) as outcome and UVR, age, skin type, body mass index, vitamin D from dietary sources, smoking, age at completed full-time education and season of blood sampling as fixed-effect predictors.

RESULTS

One interquartile range increase in UVR exposure was associated with decreased levels of 17β-estradiol (-15.6 pmol/L, 95 % Confidence Interval (CI): -27.69, -3.51) and estrone (-13.36 pmol/L, 95 % CI: -26.04, -0.68) and increased levels of follicle stimulating hormone (9.34IU/L, 95 % CI: 2.91, 15.77) and luteinizing hormone (13.86 IU/daL, 95 % CI: 2.48, 25.25).

CONCLUSIONS

Exposure to UVR is associated with decreased estrogens and increased gonadotropins in postmenopausal women, a status associated with osteoporosis, lung function decline and other adverse health effects. This study indicates that managing UVR exposure has potential to influence the hormone balance and counteract adverse health conditions after menopause.

Guidelines informing counseling on female age-related fertility decline: a systematic review

PURPOSE

To identify, appraise, and assess clinical practice guidelines informing patient counseling on female age-related fertility decline.

METHODS

Searched electronic database records from January 1, 2006, to September 10, 2018, and professional society websites. The search terms included iterations of "guideline," "counseling," "preconception," "age-related fertility decline," and "reproductive life planning." English-language professional organization guidelines addressing patient counseling on age-specific reproductive health topics were included. Assessed the methodological quality of included guidelines using the AGREE II instrument. Guidelines were categorized as high quality or low quality based on AGREE II scores. Extracted age-specific reproductive health recommendations of high-quality guidelines.

RESULTS

The search identified 2918 records. Nineteen records addressed counseling on age-related fertility decline; only 6 focused only on reproductive aging, with the remaining 13 covering related topics. Eleven met criteria for high quality. All high-quality guidelines had high "rigor of development" scores on AGREE II. Ten high-quality guidelines stated an age at which female fertility declines, ranging from 30 to "late 30s." One recommended a specific age at which patients should be counseled. Five of eleven high-quality guidelines did not discuss the obstetric and perinatal risks of advanced maternal age.

CONCLUSIONS

Few high-quality guidelines address counseling on female age-related fertility decline, and existing guidance on reproductive aging counseling is inconsistent and incomplete. Greater rigor of development and incorporation of age-specific counseling recommendations into clinical practice guidelines could lead to improved patient anticipatory guidance and more informed reproductive choices.

The Swiss Perimenopause Study - study protocol of a longitudinal prospective study in perimenopausal women

BACKGROUND

The perimenopause is associated with considerable biopsychosocial changes. The majority of women manage to adjust to these changes and cope well with the shift from reproductive to non-reproductive life. However, some women develop burdensome physical and psychological symptoms during the perimenopause. A strong link between menopausal complaints and depressed mood has been shown in this regard. To date, the decisive factors determining whether a woman will successfully achieve a healthy transition remain unclear. Thus, the purpose of this study is to investigate a range of theory-based markers related to health in perimenopausal women.

METHODS

The Swiss Perimenopause Study comprises a sample of 135 healthy perimenopausal women aged 40-56. A variety of health-related genetic, epigenetic, endocrinological, physiological, and psychosocial markers associated with the menopausal transition are investigated over a period of 13 months.

DISCUSSION

The Swiss Perimenopause Study will contribute to a better understanding of the biopsychosocial processes associated with the perimenopause, which should help to improve the clinical care of women undergoing the menopausal transition.

The impact of age beyond ploidy: outcome data from 8175 euploid single embryo transfers

PURPOSE

The rate of embryonic aneuploidy increases with increasing female age and is the primary cause of lower pregnancy and live birth rates (LBR) in older reproductive age women. This retrospective cohort study evaluates single euploid embryo transfers to determine whether an age-related decline in reproductive efficiency persists.

METHODS

A total of 8175 non-donor single embryo transfers (SET) after pre-implantation testing for aneuploidy (PGT-A) and cryopreservation were included. These were divided into five groups by patient age: < 35 years old (n = 3789 embryos transferred), 35-37 (n = 2200), 38-40 (n = 1624), 41-42 (n = 319), and > 42 (n = 243). Implantation rate (IR), clinical pregnancy rate (CPR), and LBR were calculated for each group as a percentage of embryos transferred and compared. CPR was also analyzed as a percentage of implanted pregnancies, and LBR as a percentage of clinical pregnancies, to determine when age has the greatest impact. These results were then adjusted for confounding variables via a multivariate logistic regression model.

RESULTS

Implantation rates negatively correlated with age. After adjusting for confounders, women 38 years or older had a significantly lower IR than those under 35 (OR 0.85, 95%CI 0.73-0.99 for 38-40 years old; 0.69, 0.53-0.91 for 41-42, and 0.69, 0.51-0.94 for > 42). These differences are also apparent in CPR and LBR. The rates of progression to clinical pregnancy and live birth did not differ significantly by age group. Other factors observed to affect IR independently were anti-Müllerian hormone (AMH), day of embryo transfer, and embryo morphology.

CONCLUSION

While selection of euploid embryos may be effective in overcoming a significant proportion of the age-related decline in reproductive efficiency, a decrease in IR, CPR, and LBR persists even when analyzing only euploid embryo transfers. The observed impact of aging is, therefore, independent of ploidy, as well as of other variables that affect reproductive efficiency. These results indicate that factors other than aneuploidy contribute to reproductive senescence.

Late-life consequences of short-term exposure to di(2-ethylhexyl) phthalate and diisononyl phthalate during adulthood in female mice

Di(2-ethylhexyl) phthalate (DEHP) is a known endocrine disruptor and diisononyl phthalate (DiNP) is a common DEHP replacement chemical. However, little is known about late-life consequences due to DEHP or DiNP exposure during adulthood. Thus, this study tested the hypothesis that adult exposure to DEHP or DiNP affects female reproductive parameters during late-life in female mice. Female CD-1 mice (age 39-40 days) were dosed with either vehicle control, DEHP (20 μg/kg/day-200 mg/kg/day), or DiNP (20 μg/kg/day-200 mg/kg/day) for 10 days and breeding trials were conducted at 12 and 15 months post-dosing. Further, ovaries and sera were collected at 12, 15, and 18 months post-dosing. DEHP and DiNP disrupted estrous cyclicity, increased pregnancy loss, decreased fertility, altered the sex ratio of pups, altered ovarian follicle populations, and disrupted hormone levels. Collectively, these data show that short-term exposure to DEHP or DiNP during adulthood has long-term consequences in late-life.

Residential surrounding greenspace and age at menopause: A 20-year European study (ECRHS)

BACKGROUND

Menopause is associated with a number of adverse health effects and its timing has been reported to be influenced by several lifestyle factors. Whether greenspace exposure is associated with age at menopause has not yet been investigated.

OBJECTIVE

To investigate whether residential surrounding greenspace is associated with age at menopause and thus reproductive aging.

METHODS

This longitudinal study was based on the 20-year follow-up of 1955 aging women from a large, population-based European cohort (ECRHS). Residential surrounding greenspace was abstracted as the average of satellite-based Normalized Difference Vegetation Index (NDVI) across a circular buffer of 300 m around the residential addresses of each participant during the course of the study. We applied mixed effects Cox models with centre as random effect, menopause as the survival object, age as time indicator and residential surrounding greenspace as time-varying predictor. All models were adjusted for smoking habit, body mass index, parity, age at menarche, ever-use of contraception and age at completed full-time education as socio-economic proxy.

RESULTS

An increase of one interquartile range of residential surrounding greenspace was associated with a 13% lower risk of being menopausal (Hazard Ratio: 0.87, 95% Confidence Interval: 0.79-0.95). Correspondingly the predicted median age at menopause was 1.4 years older in the highest compared to the lowest NDVI quartile. Results remained stable after additional adjustment for air pollution and traffic related noise amongst others.

CONCLUSIONS

Living in greener neighbourhoods is associated with older age at menopause and might slow reproductive aging. These are novel findings with broad implications. Further studies are needed to see whether our findings can be replicated in different populations and to explore the potential mechanisms underlying this association.

Amyloid-like substance in mice and human oocytes and embryos

PURPOSE

To identify and characterize amyloid-like substance (ALS) in human and mouse oocytes and preimplantation embryos.

METHODS

An experimental prospective pilot study. A total of 252 mouse oocytes and preimplantation embryos and 50 immature and in vitro matured human oocytes and parthenogenetic human embryos, from 11 consenting fertility patients, ages 18-45. Fluorescence intensity from immunofluorescent staining and data from confocal microscopy were quantified. Data were compared by one-way analysis of variance, with the least square-MEANS post-test, Pearson correlation coefficients (r), and bivariate analyses (t tests). ALS morphology was verified using transmission electron microscopy.

RESULTS

Immunostaining for ALS appears throughout the zona pellucida, as well as in the cytoplasm and nucleus of mouse and human oocytes, polar bodies, and parthenogenetic embryos, and mouse preimplantation embryos. In mouse, 2-cell embryos exhibited the highest level of ALS (69000187.4 ± 6733098.07). Electron microscopy confirmed the presence of ALS. In humans, fresh germinal vesicle stage oocytes exhibited the highest level of ALS (4164.74088 ± 1573.46) followed by metaphase I and II stages (p = 0.008). There was a significant negative association between levels of ALS and patient body mass index, number of days of ovarian stimulation, dose of gonadotropin used, time between retrieval and fixation, and time after the hCG trigger. Significantly higher levels of ALS were found in patients with AMH between 1 and 3 ng/ml compared to < 1 ng/ml.

CONCLUSION

We demonstrate for the first time the presence, distribution, and change in ALS throughout some stages of mouse and human oocyte maturation and embryonic development. We also determine associations between ALS in human oocytes with clinical characteristics.

elegans

C. elegans hermaphrodites display dramatic age-related decline of reproduction early in life, while somatic functions are still robust. To understand reproductive aging, we analyzed the assembly line of oocyte production that generates fertilized eggs. Aging germlines displayed both sporadic and population-wide changes. A small fraction of aging animals displayed endomitotic oocytes in the germline and other defects. By contrast, all animals displayed age-related decreases in germline size and function. As early as day 3 of adulthood, animals displayed fewer stem cells and a slower cell cycle, which combine to substantially decrease progenitor zone output. The C. elegans germline is the only adult tissue that contains stem cells, allowing the analysis of stem cells in aging. To investigate the mechanism of the decrease in stem cell number, we analyzed the Notch signaling pathway. The Notch effectors LST-1 and SYGL-1 displayed age-related decreases in expression domains, suggesting a role for Notch signaling in germline aging. The results indicate that although sporadic defects account for the sterility of some animals, population-wide changes account for the overall pattern of reproductive aging.

Aging in the Drosophila ovary: contrasting changes in the expression of the piRNA machinery and mitochondria but no global release of transposable elements

Background

Evolutionary theory indicates that the dynamics of aging in the soma and reproductive tissues may be distinct. This difference arises from the fact that only the germline lineage establishes future generations. In the soma, changes in the landscape of heterochromatin have been proposed to have an important role in aging. This is because redistribution of heterochromatin during aging has been linked to the derepression of transposable elements and an overall loss of somatic gene regulation. A role for changes in the chromatin landscape in the aging of reproductive tissues is less well established. Whether or not epigenetic factors, such as heterochromatin marks, are perturbed in aging reproductive tissues is of interest because, in special cases, epigenetic variation may be heritable. Using mRNA sequencing data from late-stage egg chambers in Drosophila melanogaster, we characterized the landscape of altered gene and transposable element expression in aged reproductive tissues. This allowed us to test the hypothesis that reproductive tissues may differ from somatic tissues in their response to aging.

Results

We show that age-related expression changes in late-stage egg chambers tend to occur in genes residing in heterochromatin, particularly on the largely heterochromatic 4th chromosome. However, these expression differences are seen as both decreases and increases during aging, inconsistent with a general loss of heterochromatic silencing. We also identify an increase in expression of the piRNA machinery, suggesting an age-related increased investment in the maintenance of genome stability. We further identify a strong age-related reduction in the expression of mitochondrial transcripts. However, we find no evidence for global TE derepression in reproductive tissues. Rather, the observed effects of aging on TEs are primarily strain and family specific.

Conclusions

These results identify unique responses in somatic versus reproductive tissue with regards to aging. As in somatic tissues, female reproductive tissues show reduced expression of mitochondrial genes. In contrast, the piRNA machinery shows increased expression during aging. Overall, these results also indicate that global loss of TE control observed in other studies may be unique to the soma and sensitive to genetic background and TE family.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5668-3) contains supplementary material, which is available to authorized users.

[Electroacupuncture Intervention Improves Physical Power of Aged Rats with Low Testosterone by Reducing Chronic Inflammatory Response of Leydig Cells]

OBJECTIVE

To assess the effect of electroacupuncture (EA) on chronic inflammatory response of Leydig cells in aged rats with low testosterone, so as to investigate its underlying mechanism of anti-male reproductive aging.

METHODS

Twenty-four 20 months old SD rats were randomly divided into EA, medication and aged control groups (n＝ 8 in each), and other 8 young SD rats (2 months of age) were used as the youth control group. EA (2 Hz/100 Hz, 1 mA) was applied to "Guanyuan"(CV 4) and bilate-ral "Shenshu"(BL 23) for 15 min, once daily for 8 weeks except the weekends. The medication group received abdominal subcutaneous injection of testosterone propionate (7 mg• kg^－1• 3 d^－1) for 8 weeks. The aged control group and the youth control group received subcutaneous injection of 0.9% normal saline, with the same dose and same treatment frequency as those of the medication group. The rats' physical power was assessed according to the exhausted swimming duration, and the levels of serum total testosterone (TT) and free testosterone(FT) were determined by ELISA. The pathological changes of the testis tissue were detected by using H．E.staining, and the immunoactivity of cyclooxygenase-2 (COX-2) in Leydig cells was detected by immunohisto-chemistry. The expression levels of nuclear factor-κB p 65 (NF-κB p 65), COX-2, interleukin-1 β (IL-1 β) and tumor necrosis factor-α (TNF-α) proteins in the testis tissues were determined by Western blot.

RESULTS

Before and after treatment, the exhaustive swimming duration and the levels of serum TT and FT in the aged control group were significantly lower than those of the youth control group (P < 0.01). After the treatment, the exhaustive swimming duration and serum TT and FT in the EA and medication groups were notably higher than those in the aged control group (P<0.01). HE staining showed that the incompleteness of basement membrane of spermatogenic tubules, reduction of spermatogenic cells and supporting cells and irregularity of Leydig cells in the testis tissue of the aged rats were relatively milder after EA intervention. Compared with the youth control group, the expression levels of NF-κB p 65 and COX-2, IL-1 β and TNF-α in the testicular tissue were significantly higher in the aged control group (P<0.01),while in compared with the aged control group, the expression levels of NF-κB p 65, COX-2, IL-1 β and TNF-α proteins were significantly down-regulated in the EA group (P<0.01).

CONCLUSION

EA intervention can improve the physical power of the aged rats with low testosterone, which may be related to its effects in up-regulating TT and FT levels, and in reducing chronic inflammatory response in the testis tissue.

Telomeres and genomic instability during early development

Genomic instability is widespread during early embryo development. Aneuploidy, mosaicism, and copy number variants (CNVs) commonly appear in human preimplantation embryos. Both age-dependent meiotic aneuploidy and age-independent mitotic aneuploidy and CNVs occur In human embryos. Telomere attrition, which contributes to genomic instability in somatic cells, also may promote genomic instability in preimplantation embryos. Telomere dynamics during gametogenesis are strikingly dimorphic between females and males. Sperm telomeres lengthen with advancing paternal age, while oocyte telomeres are among the shortest in the body. Spermatogonia express telomerase activity throughout the life of the male, while oocytes and cleavage stage embryos express low or un-measureable levels of telomerase activity. Telomere attrition in oocytes contributes to meiotic dysfunction, including spindle dysmorphologies, reduced synapsis and chiasmata, as well as delayed, arrested and fragmented embryos. Cleavage stage embryos, with such inefficient telomere reconstitution, likely undergo NHEJ, which produces anaphase lag, chromosome bridges, micronuclei, and genomic instability, including mosaicism and CNVs. Cleavage stage embryos reconstitute the short telomeres inherited from their mothers by Alternative Lengthening of Telomeres (ALT), a DNA recombination based method involving RAD 50, MRE 11, Werner and Bloom proteins, as well as telomere sister chromatid exchange. ALT robustly reconstitutes telomeres, but also predisposes to genomic instability.

Menstrual Cycle Hormone Changes Associated with Reproductive Aging and How They May Relate to Symptoms

Key cycle changes occur as women transition from reproductive life to menopause, and they can be roughly linked to menopausal staging. It is important to understand the types of studies that inform the current knowledge. Patterns of symptoms within menstrual cycles (sleep, headache) generally favor worsening in association with the perimenstrual phase of the cycle, and patterns of chronic symptoms, such as hot flashes and adverse mood, appear to be worse when hormones are more variable.

Is the aging human ovary still ticking?: Expression of clock-genes in luteinized granulosa cells of young and older women

Background

It has been shown – mostly in animal models - that circadian clock genes are expressed in granulosa cells and in corpora luteum and might be essential for the ovulatory process and steroidogenesis.

Objective

We sought to investigate which circadian clock genes exist in human granulosa cells and whether their expression and activity decrease during aging of the ovary.

Study design

Human luteinized granulosa cells were isolated from young (age 18–33) and older (age 39–45) patients who underwent in-vitro fertilization treatment. Levels of clock genes expression were measured in these cells 36 h after human chorionic gonadotropin stimulation.

Methods

Human luteinized granulosa cells were isolated from follicular fluid during oocyte retrieval. The mRNA expression levels of the circadian genes CRY1, CRY2, PER1, PER2, CLOCK, ARNTL, ARNTL2, and NPAS2 were analyzed by quantitative polymerase chain reaction.

Results

We found that the circadian genes CRY1, CRY2, PER1, PER2, CLOCK, ARNTL, ARNTL2, and NPAS2, are expressed in cultured human luteinized granulosa cells. Among these genes, there was a general trend of decreased expression in cells from older women but it reached statistical significance only for PER1 and CLOCK genes (fold change of 0.27 ± 0.14; p = 0.03 and 0.29 ± 0.16; p = 0.05, respectively).

Conclusions

This preliminary report indicates that molecular circadian clock genes exist in human luteinized granulosa cells. There is a decreased expression of some of these genes in older women. This decline may partially explain the decreased fertility and steroidogenesis of reproductive aging.

Exogenous female sex steroids may reduce lung ageing after menopause: A 20-year follow-up study of a general population sample (ECRHS)

OBJECTIVES

Menopause involves hypoestrogenism, which is associated with numerous detrimental effects, including on respiratory health. Hormone replacement therapy (HRT) is often used to improve symptoms of menopause. The effects of HRT on lung function decline, hence lung ageing, have not yet been investigated despite the recognized effects of HRT on other health outcomes.

STUDY DESIGN

The population-based multi-centre European Community Respiratory Health Survey provided complete data for 275 oral HRT users at two time points, who were matched with 383 nonusers and analysed with a two-level linear mixed effects regression model.

MAIN OUTCOME MEASURES

We studied whether HRT use was associated with the annual decline in forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁).

RESULTS

Lung function of women using oral HRT for more than five years declined less rapidly than that of nonusers. The adjusted difference in FVC decline was 5.6 mL/y (95%CI: 1.8 to 9.3, p = 0.01) for women who had taken HRT for six to ten years and 8.9 mL/y (3.5 to 14.2, p = 0.003) for those who had taken it for more than ten years. The adjusted difference in FEV₁ decline was 4.4 mL/y (0.9 to 8.0, p = 0.02) with treatment from six to ten years and 5.3 mL/y (0.4 to 10.2, p = 0.048) with treatment for over ten years.

CONCLUSIONS

In this longitudinal population-based study, the decline in lung function was less rapid in women who used HRT, following a dose-response pattern, and consistent when adjusting for potential confounding factors. This may signify that female sex hormones are of importance for lung ageing.

Declining Fertility with Reproductive Aging: How to Protect Your Patient's Fertility by Knowing the Milestones

Protection of fertility shares many of the same concepts as optimization of general health, such as smoking cessation, maintenance of a healthy body weight, and moderation of alcohol intake. Increasing attention has been placed on minimizing exposures to known reproductive toxicants. There are few conclusive data to support specific diet patterns or supplements for fertility. Ovarian reserve testing has been explored as potential diagnostic tests for assessment of reproductive aging with some controversy. Finally, the development of vitrification in the assisted reproduction laboratory has increased the success and, therefore, access to fertility preservation by way of oocyte or embryo cryopreservation.

Risk of asthma onset after natural and surgical menopause: Results from the French E3N cohort

BACKGROUND

The gender switch in asthma incidence around puberty has been put forward to suggest a role of sex hormones in asthma. However, there are limited and inconsistent findings on change in asthma incidence with menopause. We aimed to investigate the associations between menopause and asthma incidence, and interactions with overweight/obesity.

METHODS

Asthma incidence was assessed in 67,872 women free of asthma at baseline (aged 41-68 years) and regularly followed up as a part of the French E3N cohort. Adjusted hazard ratios (aHR) were derived from Cox models considering age as the time-scale, menopausal status as a time-varying covariate and taking into account menopausal treatment.

RESULTS

During 843,243 person-years of follow-up, 1205 new-onset asthma cases were identified. Compared with pre-menopause, surgical menopause was associated with an increased risk of asthma onset (aHR = 1.33 [95%CI 1.01-1.75]) but no association was observed for natural menopause (aHR = 1.05 [0.84-1.32]). In women with natural menopause, a further analysis separating the transition through menopause and the later post-menopausal period did not show any change in asthma incidence with menopause in the total sample or in normal-weight women alone. However, in overweight/obese women, peri-menopausal and post-menopausal women had an increased risk of developing asthma compared with pre-menopausal women of the same age (aHR = 1.91 [1.00-3.66] and aHR = 2.08 [1.07-4.06] respectively).

CONCLUSION

Surgical menopause was associated with an increased risk of asthma onset. For natural menopause, no change in asthma incidence was observed in normal-weight women. However, overweight/obese women had an increased risk of developing asthma after natural menopause.

Counseling patients on reproductive aging and elective fertility preservation-a survey of obstetricians and gynecologists' experience, approach, and knowledge

PURPOSE

What are the experience, approach, and knowledge of US Obstetricians and Gynecologists' (ob-gyn) towards counseling patients on reproductive aging (RA) and elective fertility preservation (EFP).

METHODS

A cross-sectional survey emailed by the American College of Obstetricians and Gynecologists (ACOG) to 5000 ACOG fellows consisting of 9 demographic and 28 questions relating to counseling patients on RA and EFP.

RESULTS

Seven hundred and eighty-four responders completed the survey. Although 82.8% agreed that conversations relating to RA should take place with patients desiring future childbearing and delaying due to social reasons, only 27.6% stated that they frequently counsel these women aged 18-34 years old, compared to 75.8% aged 35-44 years old (P < 0.01). Limited time (75.8%) and limited knowledge (41.4%) were amongst the most frequent reported barriers towards counseling patients on RA. Fifty-eight percent stated that they have been asked about EFP by patients. Although 74.8% agreed that conversations should take place related to EFP in women desiring future childbearing and delaying due to social reasons, only 27.6% stated that they frequently counsel these patients on EFP (P < 0.01). Limited time (75%) and limited knowledge (59.9%) were amongst the most frequent barriers towards counseling on EFP.

CONCLUSIONS

In the USA, methods to improve patient counseling and provider knowledge on RA and EFP are warranted and further studies are needed to address optimal methods to improve counseling and knowledge related to these topics.

Estrogen and Environmental Enrichment Differentially Affect Neurogenesis, Dendritic Spine Immunolabeling and Synaptogenesis in the Hippocampus of Young and Reproductively Senescent Female Rats

BACKGROUND

Studies examining the ability of estrogen replacement therapy (ERT) to enhance memory in women, and in animal models, have not produced consistent results. However, studies examining the effects of activity and exposure to novel environments consistently find enhancement of memory.

METHODS

An animal model of reproductive aging was used to determine if estradiol (E2) replacement, activity, and/or exposure to an enriched environment could act synergistically to improve memory, and neural correlates of memory. Young (3 months) and reproductively senescent (12 months) female rats were ovariectomized and received either vehicle or E2 treatment. Rats were assigned to 1 of 3 exposures; control: rats remained in their cage; maze control: rats were put into a pen where they could move and explore; enriched maze: rats were put into a pen with various items to climb on or investigate. The amount of time rats were active in each environment was measured. On the third day of exposure, one of the items in the enriched environment was exchanged, and the amount of time animals spent investigating the new item was used as a measure of memory.

RESULTS

E2 increased activity, immunostaining for proliferating cell nuclear antigen, and synaptic markers, synaptophysin and spinophilin, in the hippocampus of all animals. However, E2- and activity-induced changes in these markers were more pronounced in young rats. Only young rats displayed improved recognition in response to E2.

CONCLUSIONS

Older rats may need an extended period of ERT or increased activity before the benefits on memory become apparent.

Post-reproductive parthenogenetic pea aphids (Acyrthosiphon pisum) are visually identifiable and disproportionately positioned distally to clonal colonies

The role of kin-selection in the evolution of post-reproductive life is controversial. While anthropological and demographic studies strongly suggest that humans and a few other species experience kin selection for significant post-reproductive survival, these results are necessarily correlational. Understanding could therefore be advanced by the development of a globally available, field and laboratory tractable experimental model of kin-selected post-reproductive survival. In only one invertebrate (Quadrartus yoshinomiyai, a gall-forming aphid endemic to Japan) have individuals too old to reproduce been shown to be both numerous in natural habitats and able to help close relatives survive or reproduce. Pea aphids, (Acyrthosiphon pisum), common, tractable organisms, frequently outlive their reproductive ages in laboratories, live in tight interacting groups that are often clonal, and therefore should be evaluated as potential model organisms for the study of adaptive post-reproductive life. The first major step in this process is to identify an optimal method for assessing if a parthenogenetic adult is post-reproductive. We evaluated three methods, relying respectively on isolation in clip cages, visual examination for embryonic eyespots, and dissection. In every case each method identified the same individuals as reproductive versus post-reproductive. While the clip-cage method requires a multi-day wait to produce data, and dissection is inevitably fatal, the eyespot method is quick (under one minute per individual) easy, and non-invasive. This method makes it possible to accurately assess the post-reproductive status of a large number of parthenogenetic pea aphids. We demonstrate the usefulness of the eyespot method in showing that while reproductively valuable adults tend to place themselves near the centers of clonal colonies, less valuable post-reproductive adults are more often at or beyond the edges of colonies. These encouraging early results provide both impetuous and aid for further investigations into the post-reproductive lives of pea aphids.

Impact of female age and nulligravidity on fecundity in an older reproductive age cohort

OBJECTIVE

To provide female age-related estimates of fecundity and incidence of infertility by history of prior pregnancy among women 30-44 years of age.

DESIGN

Prospective, time-to-pregnancy cohort study.

SETTING

Not applicable.

PATIENT(S)

Women, between 30 and 44 years of age, attempting to conceive for ≤3 months, and no known history of infertility, polycystic ovarian syndrome (PCOS), or endometriosis.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Fecundability and incidence of infertility.

RESULT(S)

Compared to women aged 30-31 years, fecundability was reduced by 14% in women 34-35 years of age (fecundability ratio [FR] 0.86, 95% confidence interval [CI] 0.68-1.08), 19% in women 36-37 years of age (FR 0.81, 95% CI 0.60-1.08, 30% in women 38-39 years of age (FR 0.70, 95% CI 0.48-1.01), 53% in women 40-41 years of age (FR 0.47, 95% CI 0.28-0.78), and 59% in women 42-44 years of age (FR 0.39, 95% CI 0.16-0.93). Fecundability did not differ between women aged 30-31 years and 32-33 years. In general, fecundability and cumulative probability of pregnancy was lower for women who had never had a prior pregnancy.

CONCLUSION(S)

Women experience a significant reduction in fecundity and increase in the probability of infertility in their late thirties. At any age >30 years, women who have never conceived have a lower probability of achieving a pregnancy.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01028365.

Telomere length and age-at-menopause in the US

OBJECTIVES

Age-at-menopause and leukocyte telomere length (LTL) are both associated with biologic aging. Therefore, it would be reasonable to hypothesize that LTL may also serve as a marker for reproductive aging as shorter LTL may be associated with earlier age-at-menopause.

METHODS

We analyzed data from 799 post-menopausal (ages 41-85) participants in the National Health and Nutrition Examination Survey (1999-2002), a nationally representative sample of U.S. women.

RESULTS

Controlling for behavioral, socio-demographic, and health-related determinants of menopause, we found that among non-Hispanic white women, an increase of one standard deviation in LTL was associated with a 0.43 year higher reported age-at-menopause. Among Mexican-Americans, an increase of one standard deviation in LTL was associated with a 1.56 year earlier menopause. There was no significant association between LTL and age-at-menopause among non-Hispanic black women.

CONCLUSIONS

Our main finding is evidence of a strong interaction by race/ethnicity in the association between LTL and age-at-menopause. This evidence does not support the hypothesis that shorter LTL is a predictor of earlier age-at-menopause, as the magnitude and direction of the associations between LTL and age-at-menopause varied across racial/ethnic groups.

Oocyte aging underlies female reproductive aging: biological mechanisms and therapeutic strategies

In recent years, postponement of marriage and childbearing in women of reproductive age has led to an increase in the incidence of age-related infertility. The reproductive aging process in women is assumed to occur due to a decrease in both the quantity and quality of the oocytes, with the ultimate result being a decline in fecundity. This age-related decline in fecundity is strongly dependent on oocyte quality, which is critical for fertilization and subsequent embryo development. Aged oocytes display increased chromosomal abnormality and dysfunction of cellular organelles, both of which factor into oocyte quality. In particular, mitochondrial dysfunction has been suggested as a major contributor to the reduction in oocyte quality as well as to chromosomal abnormalities in aged oocytes and embryos. Participation of oxidative stress in the oocyte aging process has been proposed because oxidative stress has the capacity to induce mitochondrial dysfunction and directly damage many intracellular components of the oocytes such as lipids, protein, and DNA. In an attempt to improve mitochondrial function in aged oocytes, several therapeutic strategies have been investigated using both animal models and assisted reproductive technology. Here, we review the biological mechanisms and present status of therapeutic strategies in the female reproductive aging field and indicate possible future therapeutic strategies.

An assessment of anti-Müllerian hormone in predicting mating outcomes in female hamsters that have undergone natural and chemically-accelerated reproductive aging

In mammals, female fertility declines with age due in part to a progressive loss of ovarian follicles. The rate of follicle decline varies among individuals making it difficult to predict the age of onset of reproductive senescence. Serum anti-Müllerian hormone (AMH) concentrations correlate with the numbers of ovarian follicles, and therefore, AMH could be a useful predictor of female fertility. In women and some production animals, AMH is used to identify which individuals will respond best to ovarian stimulation for assisted reproductive technologies. However, few studies have evaluated AMH's predictive value in unassisted reproduction, and they have yielded conflicting results. To assess the predictive value of AMH in the context of reproductive aging, we prospectively measured serum AMH in 9-month-old Siberian hamsters shortly before breeding them. Female Siberian hamsters experience substantial declines in fertility and fecundity by 9months of age. We also measured serum AMH in 5-month-old females treated with 4-vinylcyclohexene diepoxide (VCD), which selectively destroys ovarian follicles and functionally accelerates ovarian aging. Vehicle-treated 5-month-old females served as controls. AMH concentrations were significantly reduced in VCD-treated females yet many females with low AMH reproduced successfully. On average, both young and old hamsters that littered had higher AMH concentrations than females that did not. However, some females with relatively high AMH concentrations failed to litter, whereas several with low AMH succeeded. Our results suggest that mean AMH concentration can predict mating outcomes on a population or group level, but on an individual basis, a single AMH determination is less informative.

Maternal undernutrition induces premature reproductive senescence in adult female rat offspring

OBJECTIVE

To determine the effects of maternal undernutrition (MUN) on the reproductive axis of aging offspring.

DESIGN

Animal (rat) study.

SETTING

Research laboratory.

ANIMAL(S)

Female Sprague-Dawley rats.

INTERVENTION(S)

Food restriction during the second half of pregnancy in rats.

MAIN OUTCOME MEASURE(S)

Circulating gonadotropins, antimüllerian hormone (AMH), ovarian morphology, estrous cyclicity, and gene expression studies in the hypothalamus and ovary in 1-day-old (P1) and aging adult offspring.

RESULT(S)

Offspring of MUN dams had low birth weight (LBW) and by adult age developed obesity. In addition, 80% of adult LBW offspring had disruption of estrous cycle by 8 months of age, with the majority of animals in persistent estrous. Ovarian morphology was consistent with acyclicity, with ovaries exhibiting large cystic structures and reduced corpora lutea. There was an elevation in circulating T, increased ovarian expression of enzymes involved in androgen synthesis, an increase in plasma LH/FSH levels, a reduction in E2 levels, and no changes in AMH in adult LBW offspring compared with in control offspring. Hypothalamic expression of leptin receptor (ObRb), estrogen receptor-α (ER-α), and GnRH protein was altered in an age-dependent manner with increased ObRb and ER-α expression in P1 LBW hypothalami and a reversal of this expression pattern in adult LBW hypothalami.

CONCLUSION(S)

Our data indicate that the maternal nutritional environment programs the reproductive potential of the offspring through alteration of the hypothalamic-pituitary-gonadal axis. The premature reproductive senescence in LBW offspring could be secondary to the development of obesity and hyperleptinemia in these animals in adult life.

The association between advanced maternal and paternal ages and increased adult mortality is explained by early parental loss

The association between advanced maternal and paternal ages at birth and increased mortality among adult offspring is often attributed to parental reproductive aging, e.g., declining oocyte or sperm quality. Less attention has been paid to alternative mechanisms, including parental socio-demographic characteristics or the timing of parental death. Moreover, it is not known if the parental age-adult mortality association is mediated by socioeconomic attainment of the children, or if it varies over the lifecourse of the adult children. We used register-based data drawn from the Finnish 1950 census (sample size 89,737; mortality follow-up 1971-2008) and discrete-time survival regression with logit link to analyze these alternative mechanisms in the parental age-offspring mortality association when the children were aged 35-49 and 50-72. Consistent with prior literature, we found that adult children of older parents had increased mortality relative to adults whose parents were aged 25-29 at the time of birth. For example, maternal and paternal ages 40-49 were associated with mortality odds ratios (ORs) of 1.31 (p<.001) and 1.22 (p<.01), respectively, for offspring mortality at ages 35-49. At ages 50-72 advanced parental age also predicted higher mortality, though not as strongly. Adjustment for parental socio-demographic characteristics (education, occupation, family size, household crowding, language) weakened the associations only slightly. Adjustment for parental survival, measured by whether the parents were alive when the child reached age 35, reduced the advanced parental age coefficients substantially and to statistically insignificant levels. These results indicate that the mechanism behind the advanced parental age-adult offspring mortality association is mainly social, reflecting early parental loss and parental characteristics, rather than physiological mechanisms reflecting reproductive aging.