The male biological clock

Social egg freezing as ambivalent materialities of aging

This commentary explores how the material-nonmaterial transactions around reproduction among women raise paradoxical questions of reproductive autonomy and commercialization of reproduction. Drawing from medical anthropological studies on human reproduction, the technology around social egg freezing has been conceived to proffer ambivalent possibilities of hope, despair, and repair as mature women recalibrate their reproductive identities, especially in pronatalist contexts. Building on the material-discursive critique of the 'material turn', I ask if social egg freezing offers an empowering biological reprieve for women who have 'chosen' a non-normative (i.e., a departure from heterosexual conjugality) life-course. Subsequently, how does one "do age" when material entanglements (here, reproductive technologies) disrupt the symbolic performance of the life-course? Or, does this reproductive autonomy actualized through social egg freezing align well with the neoliberal prerogatives of "successful aging," thereby intensifying the specter of the "Third Age"? Overall, through an analysis of (reproductive) technologies, as well as the question of choice and social bodies, I argue how new materialities and anxieties of growing old can undergird the material-cultural link in gerontology.

Reproductive axis ageing and fertility in men

Compared to women, increasing male age is not accompanied by such marked changes in reproductive function but changes certainly do happen. These include alterations to the hypothalamo-pituitary-testicular axis, with resultant implications for testosterone production and bioavailability as well as spermatogenesis. There is a decline in sexual function as men age, with a dramatic increase in the prevalence of erectile dysfunction after the age of 40, which is a marker for both clinically evident as well as covert coronary artery disease. Despite a quantitative decline in spermatogenesis and reduced fecundability, the male potential for fertility persists throughout adult life, however there are also increasingly recognised alterations in sperm quality and function with significant implications for offspring health. These changes are relevant to both natural and medically assisted conception.

The Association between Assisted Reproduction Technology (ART) and Social Perception of Childbearing Deadline Ages: A Cross-Country Examination of Selected EU Countries

The advancement of assisted reproductive technologies (ART) has gained much attention in relation to childbearing postponement. Our study's purpose was to empirically examine how perceptions of childbearing deadline age vary in association with availability and prevalence of ART across different countries. The present study used data from the 2006 European Social Survey and the 2006 European Society of Human Reproduction and Embryology to examine selected EU countries. A total sample of 17,487 respondents was examined. Multilevel regression modeling was used. Results showed that first, younger generations were more generous with maternal childbearing ages but stricter with paternal deadline ages. Second, respondents residing in countries with higher percentage of reproductive clinics per population were more generous with maternal ages, however no significant association was observed with regard to paternal childbearing ages. Third, on the contrary, respondents residing in countries with higher utilization of ART treatments were stricter with maternal ages, which may be because they are more likely to be aware of the physiological and financial difficulties associated with ART treatments. The present study is meaningful in that it is the first study to empirically examine social perceptions of childbearing ages in relation with ART.

Reproductive genetics and the aging male

PURPOSE

To examine current evidence of the known effects of advanced paternal age on sperm genetic and epigenetic changes and associated birth defects and diseases in offspring.

METHODS

Review of published PubMed literature.

RESULTS

Advanced paternal age (> 40 years) is associated with accumulated damage to sperm DNA and mitotic and meiotic quality control mechanisms (mismatch repair) during spermatogenesis. This in turn causes well-delineated abnormalities in sperm chromosomes, both numerical and structural, and increased sperm DNA fragmentation (3%/year of age) and single gene mutations (relative risk, RR 10). An increase in related abnormalities in offspring has also been described, including miscarriage (RR 2) and fetal loss (RR 2). There is also a significant increase in rare, single gene disorders (RR 1.3 to 12) and congenital anomalies (RR 1.2) in offspring. Current research also suggests that autism, schizophrenia, and other forms of "psychiatric morbidity" are more likely in offspring (RR 1.5 to 5.7) with advanced paternal age. Genetic defects related to faulty sperm quality control leading to single gene mutations and epigenetic alterations in several genetic pathways have been implicated as root causes.

CONCLUSIONS

Advanced paternal age is associated with increased genetic and epigenetic risk to offspring. However, the precise age at which risk develops and the magnitude of the risk are poorly understood or may have gradual effects. Currently, there are no clinical screenings or diagnostic panels that target disorders associated with advanced paternal age. Concerned couples and care providers should pursue or recommend genetic counseling and prenatal testing regarding specific disorders.

Decline of seminal parameters in middle-aged males is associated with lower urinary tract symptoms, prostate enlargement and bladder outlet obstruction

PURPOSE

We aimed to compare the associations between semen quality, associated reproductive indicators and the main prostate-related parameters in middle-aged men.

MATERIALS AND METHODS

This is a prospective study on 422 middle-aged men who underwent the screening for prostate health. Their reproductive function, semen quality and prostate-related pathologies were investigated.

RESULTS

Significant associations between semen quality and prostate-related parameters could be seen. Total sperm count and sperm density decreased along with the increase of the I-PSS score and total prostate volume. Also, the related lower urinary tract characteristics showed a negative correlation with main semen parameters for all investigated subjects. No significant differences in age, testicular size, and hormonal parameters were found between the subjects with or without lower urinary tract symptoms and prostate enlargement.

CONCLUSIONS

Our study suggests that altered seminal parameters in middle-aged men are associated with LUTS, prostate enlargement and/or bladder outlet obstruction. Although the assessments of prostate and lower urinary tract symptoms may not replace the semen parameters evaluating the male reproductive status, there is a need for further and more detailed investigations about the pathways behind these associations as well as possible related conditions.

Reproductive function in middle-aged males: healthy men versus male partners of infertile couples

The aim of this study was to compare the reproductive parameters and the health-related, lifestyle and educational factors in middle-aged healthy men and male partners of infertile couples. Our patient group included 164 male partners of infertile couples with a preceding period of infertility of at least 12 months and 61 men attending a prostate health screening and considering themselves healthy. Significant differences between the groups were found in testicular volume, total sperm output, density and morphology as well as oestradiol levels in serum. The analysis showed significant positive correlations between testicular volume and semen quality, while negative correlations were observed between gonadotrophin levels and sperm parameters in both groups. Physical activity and sexual capability were higher in healthy men, while coital frequency and a history of sexually transmitted diseases were higher in male partners of infertile couples. The impact of physical activity and sexual capability on semen quality for all subjects was revealed. We can conclude that impaired reproductive function, that is, semen quality, in men >45 years is related not only with general male ageing but obvious differences between subjects of infertile couples and healthy middle-aged men can be seen. Their relations with lifestyle, environmental or physiological factors need further study.

The effects of male age on sperm analysis by motile sperm organelle morphology examination (MSOME)

BACKGROUND

This study aimed to investigate the influence of age on sperm quality, as analysed by motile sperm organelle morphology examination (MSOME).

METHODS

Semen samples were collected from 975 men undergoing evaluation or treatment for infertility. Sperm cells were evaluated at 8400× magnification using an inverted microscope equipped with Nomarski (differential interference contrast) optics. Two forms of spermatozoa were considered: normal spermatozoa and spermatozoa with large nuclear vacuoles (LNV, defined as vacuoles occupying > 50% of the sperm nuclear area). At least 200 spermatozoa per sample were evaluated, and the percentages of normal and LNV spermatozoa were determined. The subjects were divided into three groups according to age: Group I, less than or equal to 35 years; Group II, 36-40 years; and Group III, greater than or equal to 41 years.

RESULTS

There was no difference in the percentages of normal sperm between the two younger (I and II) groups (P >0.05). The percentage of normal sperm in the older group (III) was significantly lower than that in the younger (I and II) groups (P < 0.05). There was no difference in the percentage of LNV spermatozoa between the younger (I and II) groups (P >0.05). The percentage of LNV spermatozoa was significantly higher in the older group (III) than in the younger (I and II) groups (P < 0.05). Regression analysis demonstrated a significant decrease in the incidence of normal sperm with increasing age (P < 0.05; r = -0.10). However, there was a significant positive correlation between the percentage of spermatozoa with LNV and male age (P < 0.05, r = 0.10).

CONCLUSION

The results demonstrated a consistent decline in semen quality, as reflected by morphological evaluation by MSOME, with increased age. Considering the relationship between nuclear vacuoles and DNA damage, these age-related changes predict that increased paternal age should be associated with unsuccessful or abnormal pregnancy as a consequence of fertilisation with damaged spermatozoa. Given that sperm nuclear vacuoles can be evaluated more precisely at high magnification, these results support the routine use of MSOME for ICSI as a criterion for semen analysis.

Social age deadlines for the childbearing of women and men

BACKGROUND

This study examines whether social age deadlines exist for childbearing in women and men, how they vary across countries, whether they are lower than actual biological deadlines and whether they are associated with childbearing at later ages and the availability of assisted reproduction techniques (ARTs).

METHODS

This study is based on the European Social Survey, Round 3 (2006-2007), which covers 25 countries. Data were gathered on social age deadlines for childbearing in women (21 909 cases) and men (21 239 cases) from samples of representative community-dwelling populations aged 15 and older.

RESULTS

Social age deadlines for childbearing were perceived more frequently for women than men. These deadlines are often lower than actual biological limits, and for women and men alike: 57.2% of respondents perceived a maternal social age deadline ≤ 40 years of age; 46.2% of the respondents perceived a paternal social age deadline ≤ 45 years of age. There is also considerable variability in deadlines across countries, as well as within them. At the country level, the presence of social age deadlines for the childbearing of women was negatively associated with birth rates at advanced ages and the prevalence of ART, and later deadlines were positively associated with these factors.

CONCLUSIONS

It is important to understand the factors that increase and limit late fertility. While biological factors condition fertility, so do social expectations. These findings provide widespread evidence across Europe that social limits exist alongside biological ones, though both sets of factors are more binding for women.

Paternal effects on early embryogenesis

Historically, less attention has been paid to paternal effects on early embryogenesis than maternal effects. However, it is now apparent that certain male factor infertility phenotypes are associated with increased DNA fragmentation and/or chromosome aneuploidies that may compromise early embryonic development. In addition, there is a growing body of evidence that the fertilizing sperm has more function than just carrying an intact, haploid genome. The paternally inherited centrosome is essential for normal fertilization, and the success of higher order chromatin packaging may impact embryogenesis. Epigenetic modifications of sperm chromatin may contribute to the reprogramming of the genome, and sperm delivered mRNA has also been hythesized to be necessary for embryogenesis. There is less information about the epigenetic factors affecting embryogenesis than genetic factors, but the epigenetics of gamete and early embryogenesis is a rapidly advancing field.

The male biological clock is ticking: a review of the literature

The term biological clock is usually used by physicians and psychologists to refer to the declining fertility, increasing risk of fetal birth defects and alterations to hormone levels experienced by women as they age. Female fecundity declines slowly after the age of 30 years and more rapidly after 40 and is considered the main limiting factor in treating infertility. However, there are several scientific reports, chapters in books and review articles suggesting that men may also have a biological clock. The aim of our study was to conduct a review of the literature, based on the Medical Literature Analysis and Retrieval System Online (Medline), to evaluate the male biological clock. After adjustments for other factors, the data demonstrate that the likelihood that a fertile couple will take more than 12 months to conceive nearly doubles from 8% when the man is < 25 years old to 15% when he is > 35 years old. Thus, paternal age is a further factor to be taken into account when deciding on the prognosis for infertile couples. Also, increasing male age is associated with a significant decline in fertility (five times longer to achieve pregnancy at the age of 45 years). Patients and their physicians therefore need to understand the effects of the male biological clock on sexual and reproductive health, in that it leads to erectile dysfunction and male infertility, as well as its potential implications for important medical conditions such as diabetes and cardiovascular diseases.