Difference in prevalence of congenital cryptorchidism in infants between two Nordic countries

Prevalence of congenital cryptorchidism in China: A nationwide population-based surveillance study, 2007-2021

BACKGROUND

Despite cryptorchidism being a common genital abnormality in male newborns with significant prevalence variations globally, there is a notable scarcity of epidemiological data on this condition in China.

OBJECTIVE

This study aimed to delineate the prevalence pattern of cryptorchidism in Chinese population over the past 15 years using nationwide surveillance data.

MATERIALS AND METHODS

Data from the China National Population-based Birth Defects Surveillance System (2007-2021) were analyzed to calculate the prevalence rates of cryptorchidism, stratified by birth year, maternal age, maternal residence, and geographic region. Adjusted prevalence rate ratios were computed using Poisson regression, while trends in prevalence and average annual percent change (AAPC) were assessed using the joinpoint regression model.

RESULTS

During the study period, a total of 1,833 cases of cryptorchidism were identified among 2,565,964 full-term male births, resulting in prevalence rates of 7.14, 5.60, and 1.54 per 10,000 births for overall, isolated, and associated cryptorchidism, respectively. The overall prevalence increased from 3.86 to 11.20 per 10,000 births, with an AAPC of 7.9% (95% confidence interval: 5.5-11.0). Significant variations were observed across maternal age (< 20 years, 7.62/10,000; 20-24 years, 6.14/10,000; 25-29 years, 6.96/10,000; 30-34 years, 7.48/10,000; ≥35 years, 9.22/10,000), maternal residence (urban vs. rural, 10.99/10,000 vs. 2.86/10,000), and geographic region (eastern, 12.38/10,000; central, 2.36/10,000; western, 2.63/10,000). Approximately one-third of cryptorchidism cases were bilaterally, while two-thirds were unilateral. Commonly observed associated abnormalities included congenital hydrocele testis, as well as anomalies in the genital organs, circulatory system, and musculoskeletal system.

CONCLUSION

Despite lower rates compared to other countries, the increasing trend in prevalence of cryptorchidism necessitates further investigation and intervention.

The epidemiology of cryptorchidism and potential risk factors, including endocrine disrupting chemicals

Congenital cryptorchidism, also known as undescended testis, is the condition where one or both testes are not in place in the scrotum at birth and is one of the most common birth defects in boys. Temporal trends and geographic variation in the prevalence of cryptorchidism from 1% to 9% have been reported in prospective cohort studies. The testes develop in the abdominal cavity and descend to the scrotum in two phases, which should be completed by gestational week 35. Thus, the risk of cryptorchidism is higher in preterm boys. In many cases a spontaneous descent occurs during the first months of life during the surge of gonadotropins and testosterone. If not, the testis is usually brought down to the scrotum, typically by surgery, to increase future fertility chances and facilitate cancer surveillance. The increasing frequency of impaired semen quality and testicular cancer, with which cryptorchidism is associated, represents a concern for male reproductive health in general and a need to understand its risk factors. The risk of cryptorchidism is closely related to gestational factors (preterm birth, low birth weight and intrauterine growth restriction), and especially maternal smoking seems to be a risk factor. Evidence is accumulating that the increasing prevalence of cryptorchidism is also related to prenatal exposure to environmental chemicals, including endocrine disrupting compounds. This association has been corroborated in rodents and supported by ecological studies. Conducting human studies to assess the effect of endocrine disrupting chemicals and their interactions is, however, challenged by the widespread concomitant exposure of all humans to a wide range of chemicals, the combined effect of which and their interactions are highly complex.

Cryptorchidism and puberty

Cryptorchidism is the condition in which one or both testes have not descended adequately into the scrotum. The congenital form of cryptorchidism is one of the most prevalent urogenital anomalies in male newborns. In the acquired form of cryptorchidism, the testis that was previously descended normally is no longer located in the scrotum. Cryptorchidism is associated with an increased risk of infertility and testicular germ cell tumors. However, data on pubertal progression are less well-established because of the limited number of studies. Here, we aim to review the currently available data on pubertal development in boys with a history of non-syndromic cryptorchidism-both congenital and acquired cryptorchidism. The review is focused on the timing of puberty, physical changes, testicular growth, and endocrine development during puberty. The available evidence demonstrated that the timing of the onset of puberty in boys with a history of congenital cryptorchidism does not differ from that of non-cryptorchid boys. Hypothalamic-pituitary-gonadal hormone measurements showed an impaired function or fewer Sertoli cells and/or germ cells among boys with a history of cryptorchidism, particularly with a history of bilateral cryptorchidism treated with orchiopexy. Leydig cell function is generally not affected in boys with a history of cryptorchidism. Data on pubertal development among boys with acquired cryptorchidism are lacking; therefore, more research is needed to investigate pubertal progression among such boys.

Surgical treatment of cryptorchidism: current insights and future directions

Cryptorchidism presents with an incidence of 1-5% with potential long-term implications on future fertility and overall health. This review focuses on surgical treatment modalities, their impact on testicular development, and function while addressing the Nordic consensus statement as well as current European Association of Urology (EAU) and American Urological Association (AUA) guidelines. Congenital and acquired cryptorchidism present distinctive challenges in surgical management, with different implications for fertility. While congenital cryptorchidism entails a risk to fertility and warrants early intervention, both retractile testes and acquired cryptorchidism also pose risks to fertility potential, underscoring the importance of evaluating treatment options. Testicular location and the child's age form the basis of a practical classification system for undescended testicles. Early diagnosis by clinical examination enables timely treatment. Imaging is reserved for selected cases only. Following guidelines, orchidopexy is recommended between 6-12 months of age for congenital cryptorchidism. Evidence increasingly suggests the benefits of early surgery for promoting testicular health and fertility potential. Current surgical options range from open to laparoscopic techniques, with the choice largely determined by the location and accessibility of the undescended testicle. The advancement in laparoscopic approaches for non-palpable testes underscores the evolving landscape of surgical treatment. Sequential surgeries may be required depending on the mobility of the undescended testes. More research is needed to explore both the potential and limitations of hormonal therapy, which is secondary to surgical treatment and can selectively have a role as adjunct to surgery. Long-term follow-up is imperative to evaluate fertility outcomes, risk of testicular malignancy, and psychological impact. By integrating current guidelines with the latest evidence, this review intends to facilitate a comprehensive understanding of cryptorchidism, thereby optimizing patient management and outcomes.

New insights on testicular cancer prevalence with novel diagnostic biomarkers and therapeutic approaches

BACKGROUND

Testicular cancer (TC), comprising merely 1% of male neoplasms, holds the distinction of being the most commonly encountered neoplasm among young males.

RECENT FINDINGS

Most cases of testicular neoplasms can be classified into two main groups, namely germ cell tumors representing approximately 95% of the cases, and sex cord-stromal tumors accounting for about 5% of the cases. Moreover, its prevalence is on the rise across the globe. TC is a neoplastic condition characterized by a favorable prognosis. The advent of cisplatin-based chemotherapeutic agents in the latter part of the 1970s has led to a significant enhancement in the 5-year survival rate, which presently surpasses 95%. Given that TC is commonly detected before reaching the age of 40, it can be anticipated that these individuals will enjoy an additional 40-50 years of life following successful treatment. The potential causes of TC are multifactorial and related to different pathologies. Accurate identification is imperative to guarantee the utmost efficacious and suitable therapy. To a certain degree, this can be accomplished through the utilization of blood examinations for neoplastic indicators; nonetheless, an unequivocal diagnosis necessitates an evaluation of the histological composition of a specimen via a pathologist.

CONCLUSION

TC is multifactorial and has various pathologies, therefore this review aimed to revise the prenatal and postnatal causes as well as novel diagnostic biomarkers and the therapeutic strategies of TC.

Bilateral versus unilateral orchidopexy: IVF/ICSI-ET outcomes

Introduction

Cryptorchidism is a common genital disorder. Approximately 20% of azoospermic or infertile men reported having histories of cryptorchidism. Bilateral cryptorchidism may have been more condemned than unilateral cryptorchidism. Early treatment by orchidopexy is the definitive procedure for cryptorchid patients with cryptorchidism. However, fertility potency after orchidopexy may be adversely affected and assisted reproduction techniques will be required for infertile patients.

Objective

To compare the reproductive outcomes between unilateral and bilateral orchidopexy groups.

Methods

A retrospective cohort study at a tertiary hospital, including a total of 99 infertile men who underwent orchidopexy to treat cryptorchidism and subsequently underwent their first IVF/ICSI-ET cycle. Men were grouped according to the laterality of their cryptorchidism and orchidopexy surgeries they received. Fertilization rate and live birth rate were chosen as parameters for evaluating outcomes.

Results

The sperm concentration and viability were significantly higher in unilateral orchidopexy group than in bilateral orchidopexy group (28.09 ± 27.99 vs 7.99 ± 14.68, P=0.001; 33.34 ± 22.52 vs 11.95 ± 17.85, P=0.001). Unilateral orchidopexy group showed lower demand for ICSI (66.07% vs 95.35%, P<0.001). Interestingly, both groups exhibited similar rates of fertilization, clinical pregnancy, live birth and birth defect. Boy birth ratio was lower in bilateral orchidopexy group as compared to unilateral orchidopexy group (27.27% vs 58.62%, P=0.026).

Conclusion

A history of bilateral orchidopexy surgery correlates with a worsened sperm parameter and a higher demand for ICSI as compared to patients with history of unilateral orchidopexy. However, this does not influence the final live birth rate.

Endocrine disrupting chemicals and their effects on the reproductive health in men

Endocrine Disrupting Chemicals (EDCs) are harmful compounds that enter the environment naturally or through anthropogenic activities and disrupt normal endocrine functions in humans, adversely affecting reproductive health. Among the most significant sources of EDC contaminants are the pharmaceutical, cosmetic, and packaging industries. EDCs have been identified to have a deteriorating effect on male reproductive system, as evidenced by the increasing number of male infertility cases. A large number of case studies have been published in which men exposed to EDCs experienced testicular cancer, undescended testicles, a decrease in serum testosterone levels, and poor semen quality. Furthermore, epidemiological evidence suggested a link between prenatal EDC exposure and cryptorchidism or undescended testicles, hypospadias, and decreased anogenital distance in infants. The majority of these findings, however, are incongruent due to the lack of long-term follow-up studies that would demonstrate EDCs to be associated with male reproductive disorders. This review aims to provide an overview on recent scientific progress on the association of EDCs to male reproductive health with special emphasis on its toxicity and possible mechanism of EDCs that disrupt male reproductive system.

Bibliometric analysis of scientific publications on cryptorchidism: Research hotspots and trends between 2000 and 2022

Background

Cryptorchidism is defined as failure of unilateral or bilateral testicular descent, which increases the risk of infertility and testicular carcinoma. Although there is much research on cryptorchidism, few studies have used the bibliometric analysis method. The purpose of this study was to conduct a comprehensive analysis of cryptorchidism from muti-dimensional perspectives to summarize the research hotspots and trends in cryptorchidism research.

Methods

Relevant studies on cryptorchidism were retrieved from the Web of Science Core Collection (WoSCC) database from 2000 to 2022. A comprehensive bibliometric analysis of cryptorchidism was performed by using the CiteSpace, Tableau Public, and VOSviewer software, including the annual distributions of publications, countries, authors, institutions, journals, references, and keywords.

Results

From January 1st, 2000 to May 17th, 2022, a total of 5023 papers concerning cryptorchidism were identified for analysis. The USA contributed the most publications (n = 1193) in this field, and the annual number of publications rose rapidly in China. The University of Melbourne published the largest number of papers (n = 131). "Hutson, John M." was the most core author ranked by publications (n = 51), and "Skakkebaek, Niels E." enjoyed the largest number of citations (4441). The JOURNAL OF UROLOGY published the largest number of papers (n = 225), while the average citations per publication of the 75 papers in HUMAN REPRODUCTION reached 62.38. Additionally, burstness analysis of references and keywords showed that cryptorchidism research was mainly focused on the exploration of the optimal mode of treatment for cryptorchidism, including hypogonadism such as Kallmann syndrome and Klinefelter syndrome.

Conclusion

Cryptorchidism has attracted continuous attention from the scientific community concerned. International collaboration in the field has witnessed significant growth in recent years and remains essential to further enhance collaborative efforts between scholars from different countries. In addition, the exploration of the optimal treatment modality for cryptorchidism, especially in the prevention of adult infertility, remains a major focus of future research. High-quality follow-up studies are also needed in the future. The pathogenesis (especially at the genetic level) and treatment of hypogonadism such as Kallmann syndrome and Klinefelter syndrome have attracted increasing attention recently, which may usher in some breakthroughs in coming years.

Diagnosis, Classification, and Contemporary Management of Undescended Testicles

This article provides a comprehensive review regarding undescended testicles and other related conditions. We have included background information summarizing variable clinical presentations, epidemiology, and the implications of undescended testis (UDT) on fertility and malignancy risk. This article has an emphasis on the approach to diagnosis and surgical management for the UDT. The purpose of this review is to provide readers with useful clinical tools for assessing and treating patients with cryptorchidism.

Reproductive toxicity of combined effects of endocrine disruptors on human reproduction

Confluence of environmental, genetic, and lifestyle variables is responsible for deterioration of human fecundity. Endocrine disruptors or endocrine disrupting chemicals (EDCs) may be found in a variety of foods, water, air, beverages, and tobacco smoke. It has been demonstrated in experimental investigations that a wide range of endocrine disrupting chemicals have negative effects on human reproductive function. However, evidence on the reproductive consequences of human exposure to endocrine disrupting chemicals is sparse and/or conflicting in the scientific literature. The combined toxicological assessment is a practical method for assessing the hazards of cocktails of chemicals, co-existing in the environment. The current review provides a comprehensive overview of studies emphasizing the combined toxicity of endocrine disrupting chemicals on human reproduction. Endocrine disrupting chemicals interact with each other to disrupt the different endocrine axes, resulting in severe gonadal dysfunctions. Transgenerational epigenetic effects have also been induced in germ cells, mostly through DNA methylation and epimutations. Similarly, after acute or chronic exposure to endocrine disrupting chemicals combinations, increased oxidative stress (OS), elevated antioxidant enzymatic activity, disrupted reproductive cycle, and reduced steroidogenesis are often reported consequences. The article also discusses the concentration addition (CA) and independent action (IA) prediction models, which reveal the importance of various synergistic actions of endocrine disrupting chemicals mixtures. More crucially, this evidence-based study addresses the research limitations and information gaps, as well as particularly presents the future research views on combined endocrine disrupting chemicals toxicity on human reproduction.

Maternal phthalate exposure during pregnancy and testis function of young adult sons

BACKGROUND

Phthalate exposure during fetal life may disrupt testicular development. Congruent with this, studies have found shorter anogenital distance, reduced penile size and altered hormone levels in infant boys whose mothers were exposed to higher levels of some phthalates during pregnancy. Few studies have explored if such adverse effects persist in adulthood. Thus, we aimed to explore if there is an association between fetal phthalate exposure and markers of testicular function in young adult men.

METHODS

In a longitudinal mother-child cohort from Copenhagen, Denmark, we examined 100 young men whose mothers during pregnancy had serum drawn and analyzed for 34 phthalate metabolites. Examinations of the young men took place at 18-20 years of age and included measurements of adult markers of testicular function (reproductive hormones, penile size, anogenital distance (AGD), testis volume, semen quality) and growth factors. Associations between maternal serum concentrations of phthalate metabolites and reproductive measures in the young men were tested using multiple linear regression.

RESULTS

Most consistently, higher maternal phthalate exposure was associated with higher luteinizing hormone (LH) but unchanged testosterone in adult sons. Congruently, higher maternal exposure was associated with lower total and free testosterone/LH ratios in adult sons. For example, twice as high maternal MiNP was associated with a 7.9 % (95 % CI 1.6-13.8) lower free testosterone/LH ratio. There was no consistent pattern of associations between the different phthalate metabolites and other reproductive hormones, clinical outcomes, or semen quality. None of the tested associations was significant after multiplicity adjustment.

CONCLUSIONS

In this exploratory study, higher maternal exposure to some phthalates was associated with impaired testicular Leydig cell function evidenced by a lower total and free testosterone/LH ratio in adult sons. This unique 18-20-year follow-up study raises concern and suggests that exposure of pregnant women to phthalates may have long-term effects on adult reproductive health in male offspring.

Levels of persistent organic pollutants in breast milk samples representing Finnish and Danish boys with and without hypospadias

Hypospadias is a congenital malformation of penile urethra with unknown etiology in most cases. Persistent organic pollutant (POP) exposure may disrupt endocrine function during a critical window of development of male genitalia. In animal studies, POPs have been associated with male reproductive disorders, including hypospadias, but only few studies have assessed this relationship in humans. The aim of this study is to investigate the association between hypospadias and POP concentration levels in breast milk, as a proxy for prenatal exposure. This is a nested case-control study of Danish and Finnish mother-son pairs. Maternal breast milk samples were collected between 1997 and 2002, and they represent infant boys born with hypospadias [n = 33 (n = 22 Danish and n = 11 Finnish)] and their 1:1 matched controls. Breast milk samples were analyzed for six classes of POPs [including dioxins, polychlorinated biphenyls, flame retardants and perfluorinated alkylated substances (PFAS)]. We estimated odds ratios (ORs) and 95% confidence intervals (CI) for each chemical class using conditional logistic regression. In addition, a composite exposure score system was used to explore the effect of a POP mixture (four chemical classes): The composite score was categorized as low, moderate, or high exposure, and differences between cases and controls were tested with conditional logistic regression. No statistically significant associations were observed between the sums of the chemical classes and hypospadias in either country. The composite score was unable to detect differences in the risk of hypospadias between the tertiles of POP exposure. Levels of PFAS were significantly higher in Danish than in Finnish breast milk samples. This small study does not provide evidence for an association between hypospadias and exposure to POPs but adds information on quantitative exposures. Further development of multi-exposure models is needed for assessing the potential mixture effect associated with multiple chemical exposures.

AMH concentrations in infancy and mid-childhood predict ovarian activity in adolescence: A long-term longitudinal study of healthy girls

BACKGROUND

Anti-Müllerian hormone (AMH) is produced by granulosa cells in small growing ovarian follicles. In adult women, serum concentrations of AMH reflect the ovarian reserve of resting primordial follicles, and low AMH is associated with risk of early menopause. In contrast, patients with polycystic ovary syndrome (PCOS) have elevated AMH. The primary aim of this study was to evaluate the individual tracking of serum AMH concentrations, as well as whether AMH in early childhood reflects ovarian activity in adolescence.

METHODS

In this large longitudinal study of healthy girls were examined from infancy to adolescence (1997-2019) including physical examination, assessment of serum concentrations of reproductive hormones (in infancy, median age 0.3 yrs; mid-childhood, 7.2 yrs; puberty, 11.3 yrs; and adolescence, 15.9 yrs), transabdominal ultrasound (TAUS, puberty and adolescence) and magnetic resonance imaging (MRI, puberty) of the ovaries.

FINDINGS

Each girl maintained her relative AMH concentration (expressed as standard deviation (SD) scores) over time; mean variation of individual age adjusted AMH concentrations was 0.56 ± 0.31 SD.Serum concentrations of AMH in adolescence correlated with AMH in infancy and childhood; infancy: r = 0.347; mid-childhood: r = 0.637; puberty: r = 0.675, all p < 0.001.AMH correlated negatively with FSH concentrations in all age groups (infancy: r = -0.645, p < 0.001; mid-childhood: r = -0.222, p < 0.001; puberty: r = -0.354, p < 0.001; adolescence: n = 275, r = -0.175, p = 0.004).Serum AMH concentrations in mid-childhood correlated with the number of follicles in puberty (TAUS and MRI) as well as in adolescence (TAUS); e.g. total number of follicles: TAUS puberty (r = 0.607), MRI puberty (r = 0.379), TAUS adolescence (r = 0.414), all p < 0.001.AMH concentration in infancy as well as in mid-childhood predicted low AMH (<10 pmol/L) in adolescence; AMH infancy <7.5 pmol/L as predictor of low AMH in adolescence: sensitivity 0.71, specificity 0.70, AUC 0.759; AMH mid-childhood < 8.4 pmol/L as predictor of low AMH in adolescence: sensitivity 0.88, specificity 0.87, AUC 0.949.Girls with high serum AMH concentration in mid-childhood (AMH >30.0 pmol/L vs. other girls) had higher adolescent LH (median 4.53 vs. 3.29 U/L p = 0.041), LH/FSH ratio (1.00 vs 0.67, p = 0.019), testosterone (1.05 vs 0.81 nmol/L, p = 0.005), total number of follicles (23 vs. 19, p = 0.004), and higher prevalence of irregular cycles (10/15 = 67% vs. 28/113 = 25%, p = 0.002).

INTERPRETATION

The present findings suggest remarkably stable ovarian activity from small growing follicles in healthy girls, supporting AMH in early life as a useful clinical tool to predict future ovarian activity.

FUNDING

The work was supported by The Center on Endocrine Disruptors (CeHoS) under The Danish Environmental Protection Agency and The Ministry of Environment and Food (grant number: MST-621-00 065), the EU (QLK4-CT1999-01422; QLK4-2001-00269), the Novo Nordisk Foundation and The Danish Ministry of Science Technology and Innovation (2107-05-0006). A.S.B. is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - 464240267. KM receives honoraria from Novo Nordisk A/S for teaching at the Danish annual postgraduate course of pituitary diseases.

Altered DNA methylation in estrogen-responsive repetitive sequences of spermatozoa of infertile men with shortened anogenital distance

BACKGROUND

It has been suggested that antenatal exposure to environmental endocrine disruptors is responsible for adverse trends in male reproductive health, including male infertility, impaired semen quality, cryptorchidism and testicular cancer, a condition known as testicular dysgenesis syndrome. Anogenital distance (AGD) is an anthropomorphic measure of antenatal exposure to endocrine disruptors, with higher exposure levels leading to shortened AGD. We hypothesized that exposure to endocrine disruptors could lead to changes in DNA methylation during early embryonic development, which could then persist in the sperm of infertile men with shortened AGD.

RESULTS

Using fluorescence activated cell sorting based on staining with either YO-PRO-1 (YOPRO) or chromomycin-3 (CMA3), we isolated four sperm fractions from eleven infertile men with short AGD and ten healthy semen donors. We examined DNA methylation in these sorted spermatozoa using reduced representation bisulfite sequencing. We found that fractions of spermatozoa from infertile men stained with CMA3 or YOPRO were more likely to contain transposable elements harboring an estrogen receptor response element (ERE). Abnormal sperm (as judged by high CMA3 or YOPRO staining) from infertile men shows substantial hypomethylation in estrogenic Alu sequences. Conversely, normal sperm fractions (as judged by low CMA3 or YO-PRO-1 staining) of either healthy donors or infertile patients were more likely to contain hypermethylated Alu sequences with ERE.

CONCLUSIONS

Shortened AGD, as related to previous exposure to endocrine disruptors, and male infertility are accompanied by increased presence of hormonal response elements in the differentially methylated regulatory sequences of the genome of sperm fractions characterized by chromatin decondensation and apoptosis.

Reproductive Markers of Testicular Function and Size During Puberty in Boys With and Without a History of Cryptorchidism

CONTEXT

Longitudinal data on levels of hypothalamic-pituitary-gonadal axis hormones and insulin-like growth factor I (IGF-I) during puberty in boys with a history of cryptorchidism are largely missing.

OBJECTIVE

We aimed to compare pubertal hormone levels between boys with a history of congenital cryptorchidism who experienced spontaneous testicular descent or underwent orchiopexy and boys without a history of cryptorchidism.

METHODS

This was a nested case-control study within a population-based birth cohort, with a prospective, longitudinal pubertal follow-up every 6 months (2005 to 2019). Participants were 109 Finnish boys, including boys with a history of unilateral cryptorchidism who underwent orchiopexy (n = 15), unilateral cryptorchidism who had spontaneous testicular descent (n = 15), bilateral cryptorchidism who underwent orchiopexy (n = 9), bilateral cryptorchidism who had spontaneous testicular descent (n = 7), and controls (n = 63). Serum reproductive hormone levels and testicular volumes were measured.

RESULTS

From around onset of puberty, boys with bilateral cryptorchidism who underwent orchiopexy had significantly higher follicle-stimulating hormone (FSH) and lower inhibin B levels than controls. Boys with unilateral cryptorchidism who underwent orchiopexy had significantly higher FSH than controls, whereas inhibin B levels were similar. Testosterone, luteinizing hormone, insulin-like factor 3, and IGF-I were generally similar between groups. Testicular volume of boys with unilateral or bilateral cryptorchidism who underwent orchiopexy was smaller than that of the controls from 1 year after pubertal onset (P < 0.05).

CONCLUSION

Cryptorchid boys, particularly those with bilateral cryptorchidism who underwent orchiopexy, had altered levels of serum biomarkers of Sertoli cells and germ cells and smaller testicular volumes compared with controls.

The Role of microRNAs in the Gonocyte Theory as Target of Malignancy: Looking for Potential Diagnostic Biomarkers

Some pediatric patients with cryptorchidism preserve cells with gonocyte characteristics beyond their differentiation period, which could support the theory of the gonocyte as a target for malignancy in the development of testicular neoplasia. One of the key molecules in gonocyte malignancy is represented by microRNAs (miRNAs). The goal of this review is to give an overview of miRNAs, a class of small non-coding RNAs that participate in the regulation of gene expression. We also aim to review the crucial role of several miRNAs that have been further described in the regulation of gonocyte differentiation to spermatogonia, which, when transformed, could give rise to germ cell neoplasia in situ, a precursor lesion to testicular germ cell tumors. Finally, the potential use of miRNAs as diagnostic and prognostic biomarkers in testicular neoplasia is addressed, due to their specificity and sensitivity compared to conventional markers, as well as their applications in therapeutics.

Testicular Sertoli Cell Hormones in Differences in Sex Development

The Sertoli cells of the testes play an essential role during gonadal development, in addition to supporting subsequent germ cell survival and spermatogenesis. Anti-Müllerian hormone (AMH) is a member of the TGF-β superfamily, which is secreted by immature Sertoli cells from the 8th week of fetal gestation. lnhibin B is a glycoprotein, which is produced by the Sertoli cells from early in fetal development. In people with a Difference or Disorder of Sex Development (DSD), these hormones may be useful to determine the presence of testicular tissue and potential for spermatogenesis. However, fetal Sertoli cell development and function is often dysregulated in DSD conditions and altered production of Sertoli cell hormones may be detected throughout the life course in these individuals. As such this review will consider the role of AMH and inhibin B in individuals with DSD.

Prevalence, management, and outcome of cryptorchidism associated with gastroschisis: A systematic review and meta-analysis

PURPOSE

Cryptorchidism associated with gastroschisis has been poorly investigated. We aimed to assess the prevalence of this association, and to address the management and outcome of cryptorchidism in this context.

MATERIALS AND METHODS

In this systematic review, we searched electronic databases (PubMed, Web of Science, and Google Scholar), without language restrictions from inception to March 31, 2021, for studies on cryptorchidism and gastroschisis co-occurrence. Random effects meta-analysis was used to calculate pooled prevalence estimates of cryptorchidism in gastroschisis and spontaneous testicular descent in this population.

RESULTS

Twenty-five studies were included for the systematic review. All were retrospective case reports or series for a total of 175 patients. Pooled prevalence estimate for cryptorchidism in gastroschisis was 19% (95% CI 13-26). Complete data sets for management and outcome analysis were available in 94 patients, involving 120 undescended testes [63 (52.5%) nonpalpable, 34 (28.3%) prolapsed outside the abdominal wall defect, and 23 (19.2%) palpable]. Fifty-five descended spontaneously, with a pooled prevalence estimate of 50% (95% CI 31-69). Twelve testes/remnants were primarily removed or absent, while 49 testes underwent orchiopexy (success rate, 63%). Excluding 4 testes still awaiting orchiopexy, 30 of the remaining 116 (25.8%) testes had a dismal outcome, including testicular loss (19), hypoplasia (8) or recurrent cryptorchidism (3).

CONCLUSION

Cryptorchidism in gastroschisis appears to occur more frequently than in the normal population. The overall mediocre testicular outcome seems to reflect the most unfavorable presentation of cryptorchidism in gastroschisis, which is represented by originally intrabdominal or prolapsed testis in the majority of cases.

LEVEL OF EVIDENCE

IV.

Serum Testosterone Levels in 3-Month-Old Boys Predict Their Semen Quality as Young Adults

CONTEXT

It remains unknown how the postnatal activation of the hypothalamic-pituitary-gonadal axis in infancy, also known as "minipuberty", relates to adult testis function.

OBJECTIVE

To investigate how markers of reproductive function in 3-month-old boys correlate with adult reproductive health parameters.

METHODS

This population-based birth cohort study (the Copenhagen Mother-Child cohort), conducted at Copenhagen University Hospital, Denmark, included 259 boys examined once around 3 months of age and again at 18 to 20 years. Reproductive hormones, penile length, testis volume, and semen quality were analyzed. Minipubertal markers of testis function (by tertiles, T1-T3) were explored as predictors of adult semen quality using linear regression models. Associations between reproductive outcomes in infancy and young adulthood were estimated by intraclass correlation coefficients (ICCs), describing how well measurements in infancy correlate with those in adulthood.

RESULTS

Serum testosterone concentration in infancy was positively associated with adult total sperm count. Median (IQR) total sperm count was 84 (54-138) million spermatozoa for boys in T1, 141 (81-286) million spermatozoa in T2, and 193 (56-287) million spermatozoa in T3. We found the highest ICC for FSH (0.41; 95% CI, 0.26-0.57), while ICCs for inhibin B, SHBG, penile length, and testis volume ranged between 0.24 and 0.27. ICCs for LH and for total and free testosterone were lower and statistically nonsignificant.

CONCLUSION

Serum testosterone in infancy was a predictor of adult total sperm count. Other reproductive hormones and genital measures showed good correlation between infancy and adulthood, suggesting that an individual's reproductive setpoint starts shortly after birth in boys and persists until adulthood.

Eicosanoid Biosynthesis in Male Reproductive Development: Effects of Perinatal Exposure to NSAIDs and Analgesic Drugs

Increasing rates of infertility associated with declining sperm counts and quality, as well as increasing rates of testicular cancer are contemporary issues in the United States and abroad. These conditions are part of the Testicular Dysgenesis Syndrome, which includes a variety of male reproductive disorders hypothesized to share a common origin based on disrupted testicular development during fetal and neonatal stages of life. Male reproductive development is a highly regulated and complex process that relies on an intricate coordination between germ, Leydig, and Sertoli cells as well as other supporting cell types, to ensure proper spermatogenesis, testicular immune privilege, and endocrine function. The eicosanoid system has been reported to be involved in the regulation of fetal and neonatal germ cell development as well as overall testicular homeostasis. Moreover, non-steroidal anti-inflammatory drugs (NSAIDs) and analgesics with abilities to block eicosanoid synthesis by targeting either or both isoforms of cyclooxygenase enzymes, have been found to adversely affect male reproductive development. This review will explore the current body of knowledge on the involvement of the eicosanoid system in male reproductive development, as well as discuss adverse effects of NSAIDs and analgesic drugs administered perinatally, focusing on toxicities reported in the testis and on major testicular cell types. Rodent and epidemiological studies will be corroborated by findings in invertebrate models for a comprehensive report of the state of the field, and to add to our understanding of the potential long-term effects of NSAID and analgesic drug administration in infants.

Anti-androgenic compounds in breast milk and cryptorchidism among Norwegian boys in the HUMIS birth cohort

The prevalence of cryptorchidism has increased over the past decades, yet its origins remain poorly understood. Testis descent is dependent on androgens and likely affected by endocrine disrupting compounds (EDCs), targeting the androgen receptor (AR). We investigated the association between anti-androgenic activity, not derived from natural hormones, in maternal breast milk and impaired testis descent among boys. We performed a case-control study based on 199 breast milk samples from 94 mothers of cryptorchid boys and 105 random non-cryptorchid boys participating in the Norwegian HUMIS (Human Milk Study) cohort. For each participant, apolar, and polar fractions were extracted, and combined to reconstitute a mixture. Anti-androgenic activity was measured in all three fractions using the human cell-based in vitro anti-AR CALUX® assay and expressed in μg of flutamide equivalent, a well-known antiandrogen. Results from fraction analyses were compared among boys with cryptorchidism and controls using multiple logistic regression, controlling for appropriate confounders identified using a directed acyclic graph. Children's daily exposure to anti-androgenic EDCs through breastfeeding was estimated to 78 μg flutamide eq./kg of body weigh/day. The activity was higher in the polar fraction (1.48 ± 1.37 μg flutamide eq./g of milk) mainly representing non-persistent chemicals, in contrast to other fractions. However, the activity in the polar extracts was decreased when in mixtures with the apolar fraction, indicating synergistic interactions. No significant difference in the activity was observed according to cryptorchid status for polar, apolar or mixed breast milk fractions. The study showed anti-androgenic activity in nearly all human milk samples, and at levels higher than the advisory threshold. However, no significant association was observed between cryptorchidism and antiandrogenic activity measured in either polar, apolar, or mixture fractions derived from breast milk.

Recent advancement in the treatment of boys and adolescents with hypogonadism

Clinical manifestations and the need for treatment varies according to age in males with hypogonadism. Early foetal-onset hypogonadism results in disorders of sex development (DSD) presenting with undervirilised genitalia whereas hypogonadism established later in foetal life presents with micropenis, cryptorchidism and/or micro-orchidism. After the period of neonatal activation of the gonadal axis has waned, the diagnosis of hypogonadism is challenging because androgen deficiency is not apparent until the age of puberty. Then, the differential diagnosis between constitutional delay of puberty and central hypogonadism may be difficult. During infancy and childhood, treatment is usually sought because of micropenis and/or cryptorchidism, whereas lack of pubertal development and relative short stature are the main complaints in teenagers. Testosterone therapy has been the standard, although off-label, in the vast majority of cases. However, more recently alternative therapies have been tested: aromatase inhibitors to induce the hypothalamic-pituitary-testicular axis in boys with constitutional delay of puberty and replacement with GnRH or gonadotrophins in those with central hypogonadism. Furthermore, follicle-stimulating hormone (FSH) priming prior to hCG or luteinizing hormone (LH) treatment seems effective to induce an enhanced testicular enlargement. Although the rationale for gonadotrophin or GnRH treatment is based on mimicking normal physiology, long-term results are still needed to assess their impact on adult fertility.

Genetics of cryptorchidism and testicular regression

Cryptorchidism, i.e., undescended testis, is one of the most common genital malformations in newborn male babies. The birth rate of cryptorchidism varies from 1.6 to 9.0 %. Etiology of disrupted testicular descent is complex and predisposing causes include genetic, hormonal, environmental, lifestyle and maternal factors. Testicular descent occurs in two major steps and testicular hormones and normal function of hypothalamic-pituitary-testicular axis are important for normal descent. Several gene mutations are associated with syndromic cryptorchidism but they are rarely found in boys with isolated undescended testis. Testicular regression can also cause an empty scrotum. Normal male genital phenotype indicates that the boy has had functioning testis during development. Torsion of the testis can cause testicular regression but in many cases the reason for vanishing testis remains elusive. In this narrative review we discuss genetics of cryptorchidism and testicular regression.

Prevalence of congenital cryptorchidism in Estonia

BACKGROUND

Cryptorchidism is one of the most common urogenital malformations. Cryptorchidism prevalence varies greatly in different countries and populations. The aim of the current study was to determine and analyse cryptorchidism prevalence in Estonia.

MATERIALS AND METHODS

During 2012-2015, all consecutively born 5014 boys at Tartu University Hospital were examined for cryptorchidism. All the subjects with cryptorchidism were followed up for at least 6 months to assess spontaneous testicular descent.

RESULTS

Note that 2.1% cases had one or both testicles undescended at birth, 1.6% cases at expected date of birth, 1% cases at 3 months of age, and 0.8% cases at the age of 6 months had cryptorchidism. Cryptorchidism prevalence at birth was higher in preterm boys (11.9%), boys of low birth weight (16.7%) and boys small for gestational age (14%) but was lower in full-term newborn boys (1.1%). During follow-up, testes descended spontaneously in 61.6% of boys, more commonly in prematurely born boys (92%) and boys with low gestational weight (93%) as compared to full-term cryptorchid boys (29.2%) and cryptorchid boys with normal birth weight (34%). At the age of 6 months, cryptorchidism prevalence was equalized in preterm boys (0.9%) and boys with low birth weight (1%) as compared to full-term boys (0.7%) and boys with normal birth weight (0.7%). Boys SGA required surgical intervention more commonly than boys with normal birth weight. Ethnically, cryptorchidism prevalence at birth was similar among Estonians and non-Estonians.

CONCLUSION

Our data revealed that cryptorchidism prevalence, especially in full-term boys, is lower in Estonia than reported in the other Nordic-Baltic countries and worldwide.

Environmental Impacts on Male Reproductive Development: Lessons from Experimental Models

BACKGROUND

Male reproductive development in mammals can be divided into a gonadal formation phase followed by a hormone-driven differentiation phase. Failure of these processes may result in Differences in Sex Development (DSD), which may include abnormalities of the male reproductive tract, including cryptorchidism, hypospadias, infertility, and testicular germ cell cancer (TGCC). These disorders are also considered to be part of a testicular dysgenesis syndrome (TDS) in males. Whilst DSDs are considered to result primarily from genetic abnormalities, the development of TDS disorders is frequently associated with environmental factors.

SUMMARY

In this review, we will discuss the development of the male reproductive system in relation to DSD and TDS. We will also describe the experimental systems, including studies involving animals and human tissues or cells that can be used to investigate the role of environmental factors in inducing male reproductive disorders. We will discuss recent studies investigating the impact of environmental chemicals (e.g., phthalates and bisphenols), lifestyle factors (e.g., smoking) and pharmaceuticals (e.g., analgesics) on foetal testis development. Finally, we will describe the evidence, involving experimental and epidemiologic approaches, for a role of environmental factors in the development of specific male reproductive disorders, including cryptorchidism, hypospadias, and TGCC. Key Messages: Environmental exposures can impact the development and function of the male reproductive system in humans. Epidemiology studies and experimental approaches using human tissues are important to translate findings from animal studies and account for species differences in response to environmental exposures.

[Environmental endocrine disruptors and fertility]

Endocrine disruptor chemicals (EDCs) are ubiquitous contaminants in the environment, wildlife, and humans. During the last 20 years, several epidemiological, clinical and experimental studies have demonstrated the role of EDCs on the reduction of male and female fertility. The concept of foetal origins of adult disease is particularly topical in the field of reproduction. Moreover, exposure to EDCs during pregnancy has been shown to influence epigenetic programming of endocrine signalling and other important physiological pathways, and provided the basis for multi- and transgenerational transmission of adult diseases. However, the large panel of EDCs simultaneously present in the air, sol and water makes the quantification of human exposition still a challenge. Gas chromatography coupled with mass spectrometry, the measurement of total plasmatic hormonal bioactivity on stably transfected cell lines as well as the EDC analysis in hair samples are useful methods of evaluation. More recently, microRNAs analysis offers a new perspective in the comprehension of the mechanisms behind the modulation of cellular response to foetal or post-natal exposure to EDCs. They will help researchers and clinicians in identifying EDCs exposition markers and new therapeutic approaches in the future.

Mixture toxicity, cumulative risk, and environmental justice in United States federal policy, 1980-2016 : Why, with much known, was little done?

Toxic chemicals - "toxicants" - have been studied and regulated as single entities, and, carcinogens aside, almost all toxicants, single or mixed and however altered, have been thought harmless in very low doses or very weak concentrations. Yet much work in recent decades has shown that toxicants can injure wildlife, laboratory animals, and humans following exposures previously expected to be harmless. Additional work has shown that toxicants can act not only individually and cumulatively but also collectively and even synergistically and that they affect disadvantaged communities inordinately - and therefore, as argued by reformers, unjustly. As late as December 2016, the last full month before the inauguration of a president promising to rescind major environmental regulations, the United States federal environmental-health establishment, as led by the Environmental Protection Agency (EPA), had not developed coherent strategies to mitigate such risks, to alert the public to their plausibility, or to advise leadership in government and industry about their implications. To understand why, we examined archival materials, reviewed online databases, read internal industry communications, and interviewed experts. We confirmed that external constraints, statutory and judicial, had been in place prior to EPA's earliest interest in mixture toxicity, but we found no overt effort, certainly no successful effort, to loosen those constraints. We also found internal constraints: concerns that fully committing to the study of complex mixtures involving numerous toxicants would lead to methodological drift within the toxicological community and that trying to act on insights from such study could lead only to regulatory futility. Interaction of these constraints, external and internal, shielded the EPA by circumscribing its responsibilities and by impeding movement toward paradigmatic adjustment, but it also perpetuated scientifically dubious policies, such as those limiting the evaluation of commercial chemical formulations, including pesticide formulations, to only those ingredients said by their manufacturers to be active. In this context, regulators' disregard of synergism contrasted irreconcilably with biocide manufacturers' understanding that synergism enhanced lethality and patentability. In the end, an effective national response to mixture toxicity, cumulative risk, and environmental injustice did not emerge. In parallel, though, the National Institute of Environmental Health Sciences, which was less constrained, pursued with scientific investigation what the EPA had not pursued with regulatory action.

Does height and IGF-I determine pubertal timing in girls?

BACKGROUND

Pubertal timing is closely linked to growth regulated by the growth hormone/insulin-like factor (GH/IGF) axis that includes IGF-regulating factors such as pregnancy-associated plasma protein-A/A2 (PAPP-A/PAPP-A2) and stanniocalcin 2 (STC2). We investigated the association between height, IGF-I concentration, and PAPPA, PAPPA2, and STC2 genotypes on the timing of female pubertal milestones.

METHODS

Height, IGF-I, and genotypes were analyzed in 1382 Danish girls from the general population, 67 patients with tall stature (height ≥2 SD), and 124 patients with short stature (height ≤-2 SD). The main outcomes were breast stage and menarche.

RESULTS

Thelarche occurred significantly earlier in patients with tall stature (mean age 9.37 years [95% confidence interval (CI) 8.87-9.87]) and later in patients with short stature (11.07 years [95% CI 10.7-11.43]) compared with girls within the normal range (9.96 years [95% CI 9.85-10.07]) (p = 0.02 and p < 0.01, respectively). Girls with higher IGF-I levels experienced thelarche and menarche earlier compared with the rest of the cohort (p < 0.01). Genotypes were not associated with age at thelarche nor menarche, but the PAPPA2 minor allele carriers were shorter compared with major allele carriers, p = 0.03.

CONCLUSIONS

Height and IGF-I, but not PAPP-A, PAPP-A2, and STC2 genotypes, were negatively associated with age at thelarche and menarche.

IMPACT

Girls with tall and short stature enter puberty earlier and later compared with girls with normal height. Girls with higher insulin-growth factor-I in childhood enter puberty earlier. Pubertal timing is influenced by longitudinal growth and IGF-I levels earlier in childhood. Childhood growth and the levels of IGF-I in childhood may be biomarkers of pubertal timing.

Congenital abdominal wall defects and cryptorchidism: a population-based study

PURPOSE

Several studies have reported high prevalence of undescended testis (UDT) among boys with congenital abdominal wall defects (AWD). Due to rarity of AWDs, however, true prevalence of testicular maldescent among these boys is not known. We conducted a national register study to determine the prevalence of UDT among Finnish males with an AWD.

METHODS

All male infants with either gastroschisis or omphalocele born between Jan 1, 1998 and Dec 31, 2015 were identified in the Register of Congenital Malformations. The data on all performed operations were acquired from the Care Register for Health Care. The register data were examined for relevant UDT diagnosis and operation codes.

RESULTS

We identified 99 males with gastroschisis and 89 with omphalocele. UDT was diagnosed in 10 (10.1%) infants with gastroschisis and 22 (24.7%) with omphalocele. Majority of these required an operation; 8/99 (8.1%) gastroschisis and 19/89 (21.3%) omphalocele patients. UDT is more common among AWD patients than general population with the highest prevalence in omphalocele.

CONCLUSIONS

Cryptorchidism is more common among boys with an AWD than general population. Furthermore, omphalocele carries significantly higher risk of UDT and need for orchidopexy than gastroschisis. Due to high prevalence testicular maldescent, careful follow-up for UDT is recommended.

Sonographic evaluation of fetal scrotum, testes and epididymis

External male genitalia have rarely been evaluated on fetal ultrasound. Apart from visualization of the penis for fetal sex determination, there are no specific instructions or recommendations from scientific societies. This study aimed to review the current knowledge about prenatal diagnosis of the scrotum and internal structures, with discussion regarding technical aspects and clinical management. We conducted an article search in Medline, EMBASE, Scopus, Google Scholar, and Web of Science databases for studies in English or Spanish language that discussed prenatal scrotal pathologies. We identified 72 studies that met the inclusion criteria. Relevant data were grouped into sections of embryology, ultrasound, pathology, and prenatal diagnosis. The scrotum and internal structures show a wide range of pathologies, with varying degrees of prevalence and morbidity. Most of the reported cases have described incidental findings diagnosed via striking ultrasound signs. Studies discussing normative data or management are scarce.

Androgenization in Klinefelter syndrome: Clinical spectrum from infancy through young adulthood

Klinefelter syndrome (KS) is an uncommon chromosomal disorder in males that has a variable clinical appearance. Classic KS involves an extra X chromosome, (47, XXY), although other variations may exist, including a milder mosaic form as well as multiple extra sex chromosomes with more dramatic phenotypes. KS is underdiagnosed, especially pre-pubertally, owing to a paucity of concrete clinical signs; however, diagnostic rates increase during and after puberty, as the consequences of hypergonadotropic hypogonadism begin to manifest. Testicular failure causing decreased circulating testosterone (T) and germ cell depletion, a hallmark feature in KS, commonly begins shortly after the onset of puberty and leads to the most commonly recognized KS traits: small testes, azoospermia, gynecomastia, decreased facial and pubic hair. While many KS men maintain adequate T levels leading up to young adulthood, some may have lower T levels at an earlier age leading to varied levels of androgenization and clinical KS features. At certain critical time points, absent or decreased T may alter the development of normal male reproductive organs, external genitalia, development of secondary sexual characteristics and spermatogenesis. Testicular failure in utero may lead to ambiguous genitalia, cryptorchidism and/or hypospadias, all of which depend on fetal T production. In the neonatal period and childhood, decreased T levels during the mini-puberty of infancy may negatively impact germ cell differentiation and male neuropsychological development. Finally, decreased T during pubertal and young adulthood can lead to decreased virilization during puberty, eunuchoid skeleton and decreased spermatogenesis. Depending on the timing of the testicular failure, a reproductive window of sperm production may exist to achieve paternity for KS men. The presence or absence of clinical characteristics reflecting decreased androgenization provides an insight to the relative testicular function during these developmental time points for those with KS and contributes to variability within the syndrome.

NR5A1 c.991-1G > C splice-site variant causes familial 46,XY partial gonadal dysgenesis with incomplete penetrance

OBJECTIVE

The study aimed to identify the genetic basis of partial gonadal dysgenesis (PGD) in a non-consanguineous family from Estonia.

PATIENTS

Cousins P (proband) 1 (12 years; 46,XY) and P2 (18 years; 46,XY) presented bilateral cryptorchidism, severe penoscrotal hypospadias, low bitesticular volume and azoospermia in P2. Their distant relative, P3 (30 years; 46,XY), presented bilateral cryptorchidism and cryptozoospermia.

DESIGN

Exome sequencing was targeted to P1-P3 and five unaffected family members.

RESULTS

P1-P2 were identified as heterozygous carriers of NR5A1 c.991-1G > C. NR5A1 encodes the steroidogenic factor-1 essential in gonadal development and specifically expressed in adrenal, spleen, pituitary and testes. Together with a previous PGD case from Belgium (Robevska et al 2018), c.991-1G > C represents the first recurrent NR5A1 splice-site mutation identified in patients. The majority of previous reports on NR5A1 mutation carriers have not included phenotype-genotype data of the family members. Segregation analysis across three generations showed incomplete penetrance (<50%) and phenotypic variability among the carriers of NR5A1 c.991-1G > C. The variant pathogenicity was possibly modulated by rare heterozygous variants inherited from the other parent, OTX2 p.P134R (P1) or PROP1 c.301_302delAG (P2). For P3, the pedigree structure supported a distinct genetic cause. He carries a previously undescribed likely pathogenic variant SOS1 p.Y136H. SOS1, critical in Ras/MAPK signalling and foetal development, is a strong novel candidate gene for cryptorchidism.

CONCLUSIONS

Detailed genetic profiling facilitates counselling and clinical management of the probands, and supports unaffected mutation carriers in the family for their reproductive decision making.

Introducing a new scrotal orchiopexy technique: The fat anchor orchiopexy

Cryptorchidism is the most common congenital anomaly of the male genital tract. Cryptorchidism is associated with potentially serious consequences including reduced fertility, increases risk of cancer, susceptibility to torsion and traumatic injury, as well as future psychological problems related to an abnormal scrotal appearance. The mainstay of orchiopexy is to achieve an adequate tension-free and permanent scrotal fixation of the testis; one that prevents recurrent ascent. A number of suggestions have been made regarding keeping the testis in the scrotal position once it was brought down in the scrotum without tension. Several techniques for testicular fixation have been described to date; however, the optimal method remains controversial. We herein introduce a novel scrotal orchidopexy technique. This innovative fixation technique utilizes the sub-scrotal fat as a permanent anchor for fixing the low-lying cryptorchid testicle in the scrotum through a trans-scrotal incision. Therefore, the procedure was named "the fat anchor orchiopexy". We believe our method will give better options for scrotal fixation especially in cases of low-lying cryptorchid testes. This article provides a detailed description of this new fixation technique.

Testicular dysgenesis syndrome and phthalate exposure: A review of literature

Endocrine disruptors are chemicals that interfere with the body's endocrine system and cause adverse effects in biological systems. Phthalates are a group of man-made chemicals which are mainly used as plasticizers and classified as endocrine disruptors. They are also used in cosmetic and personal care products as color or smell fixators. Moreover, phthalates are present in inks, adhesives, sealants, automobile parts, tools, toys, carpets, medical tubing and blood storage bags, and food packages. Pathological condition known as "testicular dysgenesis syndrome" (TDS) or "phthalate syndrome" is usually linked to phthalate exposure and is coined to describe the rise in alterations in reproductive health in men, such as reduced semen quality (decrease in sperm counts, sperm motility and increase in abnormal sperms), hypospadias, cryptorchidism, reduced anogenital distance and early-life testicular cancer. Phthalates are suggested to cause direct effect on gonadal and non-gonadal tissues, impair the differentiation and morphogenesis of seminiferous tubules and accessory sex organs and testicular cells (both Sertoli and Leydig cells), alter estradiol and/or testosterone levels, decrease insulin-like 3 (INSL3) peptide production, impair spermatogenesis and lead to epigenetic alterations, all of which may lead to TDS. This review will mainly focus on phthalates as causes of TDS and their mechanisms of action.

Ambulatory Orchidopexy Is a Potential Solution to Improve the Rate of Timely Repair in Cryptorchid Boys: An 8 Year Retrospective Study of 4,972 Cases

Background: Cryptorchidism is the most common congenital anomaly in pediatric urology. Although early surgery on cryptorchid boys is recommended by pediatric urologists worldwide, the actual age at orchidopexy is often older than the recommended age. Our medical center has started performing ambulatory orchidopexy since March 2016 at the ambulatory surgery center. We aimed to investigate whether ambulatory orchidopexy can improve the timely repair rate. Methods: A retrospective analysis was conducted from 2012 to 2019 at our medical center. Ambulatory orchidopexy was started at our medical center on March 24, 2016. Boys born on or after September 24, 2015 were classified into the "with ambulatory medical resource" group, and boys born before September 24, 2014, were classified into the "without ambulatory medical resource" group. The timely repair rates were calculated and compared. Results: A total of 4,972 cryptorchidism cases were included in the final study. Approximately 33.0% of cryptorchid boys received timely surgery (orchidopexy by the age of 18 months), and only 6.8% of all cryptorchid boys underwent surgery before the age of 1 year. After the performance of ambulatory orchidopexy, the timely repair rate increased from 25.7 to 37.0% (P < 0.001), and the percentage of patients receiving surgery before the age of 1 year increased significantly from 3.5 to 8.6% (P < 0.001). The proportion of timely repair in patients with ambulatory medical resources was significantly higher than that in patients without ambulatory medical resources (15.6% vs. 58.2%, P < 0.001). Significant changes in the rate of surgery before 12 months of age were also found between the two groups (2.4% vs. 14.8%, P < 0.001). Conclusions: After the performance of ambulatory orchidopexy in our medical center, the rates of both timely repair and receiving surgery before the age of 1 year increased significantly. Ambulatory orchidopexy is a potential solution to improve the rate of timely repair in cryptorchid boys, and it is worthy of promotion in developing countries and regions.

Review of injection techniques for spermatogonial stem cell transplantation

BACKGROUND

Although the prognosis of childhood cancer survivors has increased dramatically during recent years, chemotherapy and radiation treatments for cancer and other conditions may lead to permanent infertility in prepubertal boys. Recent developments have shown that spermatogonial stem cell (SSC) transplantation may be a hope for restoring fertility in adult survivors of childhood cancers. For this reason, several centres around the world are collecting and cryopreserving testicular tissue or cells anticipating that, in the near future, some patients will return for SSC transplantation. This review summarizes the current knowledge and utility of SSC transplantation techniques.

OBJECTIVE AND RATIONALE

The aim of this narrative review is to provide an overview of the currently used experimental injection techniques for SSC transplantation in animal and human testes. This is crucial in understanding and determining the role of the different techniques necessary for successful transplantation.

SEARCH METHODS

A comprehensive review of peer-reviewed publications on this topic was performed using the PubMed and Google Scholar databases. The search was limited to English language work and studies between 1994 (from the first study on SSC transplantation) and April 2019. Key search terms included mouse, rat, boar, ram, dog, sheep, goat, cattle, monkey, human, cadaver, testes, SSC transplantation, injection and technique.

OUTCOMES

This review provides an extensive clinical overview of the current research in the field of human SSC transplantation. Rete testis injection with ultrasonography guidance currently seems the most promising injection technique thus far; however, the ability to draw clear conclusions is limited due to long ischemia time of cadaver testis, the relatively decreased volume of the testis, the diminishing size of seminiferous tubules, a lack of intratesticular pressure and leakage into the interstitium during the injection on human cadaver testis. Current evidence does not support improved outcomes from multiple infusions through the rete testes. Overall, further optimization is required to increase the efficiency and safety of the infusion method.

WIDER IMPLICATIONS

Identifying a favourable injection method for SSC transplantation will provide insight into the mechanisms of successful assisted human reproduction. Future research could focus on reducing leakage and establishing the optimal infusion cell concentrations and pressure.

Comparison of diagnostic and treatment guidelines for undescended testis

Cryptorchidism or undescended testis is the single most common genitourinary disease in male neonates. In most cases, the testes will descend spontaneously by 3 months of age. If the testes do not descend by 6 months of age, the probability of spontaneous descent thereafter is low. About 1%-2% of boys older than 6 months have undescended testes after their early postnatal descent. In some cases, a testis vanishes in the abdomen or reascends after birth which was present in the scrotum at birth. An inguinal undescended testis is sometimes mistaken for an inguinal hernia. A surgical specialist referral is recommended if descent does not occur by 6 months, undescended testis is newly diagnosed after 6 months of age, or testicular torsion is suspected. International guidelines do not recommend ultrasonography or other diagnostic imaging because they cannot add diagnostic accuracy or change treatment. Routine hormonal therapy is not recommended for undescended testis due to a lack of evidence. Orchiopexy is recommended between 6 and 18 months at the latest to protect the fertility potential and decrease the risk of malignant changes. Patients with unilateral undescended testis have an infertility rate of up to 10%. This rate is even higher in patients with bilateral undescended testes, with intra-abdominal undescended testis, or who underwent delayed orchiopexy. Patients with undescended testis have a threefold increased risk of testicular cancer later in life compared to the general population. Self-examination after puberty is recommended to facilitate early cancer detection. A timely referral to a surgical specialist and timely surgical correction are the most important factors for decreasing infertility and testicular cancer rates.

How boys and testicles wander to surgery: a nationwide cohort study of surgical delay in Sweden

BACKGROUND

Early orchidopexy is recommended for cryptorchidism and the surgery is increasingly centralised. The objectives were to determine the incidence, risk factors and if distance to treating hospital impacted on timely treatment of cryptorchidism.

METHODS

In this observational study, all boys born in Sweden from 2001 to 2014 were followed in national registers to determine the incidence of cryptorchidism by levels of birth-related risk factors and social determinants. Travel time to hospital was used as the primary exposure in multivariable survival analysis, with age at surgery as main outcome.

RESULTS

Of 748 678 boys at risk for cryptorchidism, 7351 were treated and evaluated for timing of surgery (cumulative childhood incidence 1.4%, 95% CI 1.3% to 1.5%). The incidence was clearly associated with prematurity and overdue pregnancy (HR for <32 weeks 2.77 (95% CI 2.39 to 3.21); 32-36 weeks HR 1.36 (95% CI 1.24 to 1.49); >41 weeks HR 1.19 (95% CI 1.10 to 1.29)), low birth weight (<1000 g HR 3.94 (95% CI 3.15 to 4.92); 1000-1499 g HR 3.70 (95% CI 3.07 to 4.46); 1500-2500 g HR 1.69 (95% CI 1.52 to 1.88)) and intrauterine growth restriction (small for gestational age HR 2.38 (95% CI 2.14 to 2.65); large for gestational age HR 1.26 (95% CI 1.13 to 1.42)), but not with smoking or maternal age. Each 30 min increase in travel time was associated with a reduced probability of timely treatment (HR for being treated by age 3 adjusted for risk factors and socioeconomic determinants: 0.91 (95% CI 0.88 to 0.95)). Lower income and financial support were also associated with treatment delays (adjusted HR for lowest income quintile 0.82 (95% CI 0.72 to 0.93) and for families with financial support 0.85 (95% CI 0.73 to 0.97)).

CONCLUSIONS

Travel distance to treating hospital was associated with delayed treatment. 'Not all those who wander are lost', but these findings suggest a trade-off between centralisation benefits and barriers of geography also in elective paediatric surgery.

A history of cryptorchidism is associated with impaired testicular function in early adulthood: a cross-sectional study of 6376 men from the general population

STUDY QUESTION

Is there a difference in testicular function in early adulthood between men born with cryptorchidism and men born with normally descended testes?

SUMMARY ANSWER

In men from the general population, a history of cryptorchidism was associated with lower total testis volume and impaired semen quality as well as altered serum levels of reproductive hormones.

WHAT IS KNOWN ALREADY

The association between cryptorchidism and testicular function is well documented in studies based on sub-fertile or infertile men recruited from a clinical setting. However, the association has not previously been investigated in men from the general population, who were unselected regarding fertility status.

STUDY DESIGN, SIZE, DURATION

This is a cross-sectional population-based study of 6376 young Danish men examined from 1996 to 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

This study is based on young men from the greater Copenhagen area, Denmark (median age of 19 years) who were unselected regarding fertility status and semen quality. The young men delivered a semen sample, had a blood sample drawn and underwent a physical examination including assessment of testis volume. Participants completed a questionnaire regarding cryptorchidism at birth, current lifestyle and their mother’s pregnancy, after consulting their mother. The differences in markers of testicular function, including testis volume, semen parameters and reproductive hormones between men with and without a history of cryptorchidism were investigated with multiple linear regression analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

The participation rate was 24% for the entire study period. Overall, a history of cryptorchidism was associated with reduced testicular function. In the adjusted models, a history of cryptorchidism was associated with a 3.5 ml lower total testis volume, determined by orchidometer (P &lt; 0.001), 28% lower sperm concentration (95% CI: −37 to −20) and 26% lower inhibin B/FSH ratio (95% CI: −50 to −22) compared to men without a history of cryptorchidism, suggesting a reduced spermatogenetic capacity. Men with a history of cryptorchidism also had a slightly reduced Leydig cell function expressed as a 6% lower testosterone/LH ratio (95% CI: −12 to −0.7). The significant effect sizes and different markers of testicular function pointing in the same direction across the different models based on a large sample size support that the results are not chance findings.

LIMITATIONS, REASONS FOR CAUTION

Information on cryptorchidism at birth and treatment modus was obtained by retrospective self-report, and each participant only delivered one semen sample.

WIDER IMPLICATIONS OF THE FINDINGS

The results suggest that men with a history of cryptorchidism could be at increased risk of experiencing fertility problems. However, among these men there is a wide variation in semen quality and further research is needed in order to identify the subgroup of boys born with cryptorchidism who are at the greatest risk of impaired semen quality when reaching adulthood.

STUDY FUNDING/COMPETING INTEREST(S)

The study received financial support from the Research fund of Rigshospitalet, Copenhagen University Hospital; the European Union (Contract numbers BMH4-CT96-0314, QLK4-CT-1999-01422, QLK4-CT-2002-00603. FP7/2007-2013, DEER Grant agreement no. 212844); the Danish Ministry of Health; the Danish Environmental Protection Agency; A.P. Møller and wife Chastine McKinney Møllers Foundation; and Svend Andersens Foundation. None of the founders had any role in the study design, collection, analysis or interpretation of data, writing of the paper or publication decisions. The authors have nothing to declare.

TRIAL REGISTRATION NUMBER

N/A.

Exposure to polychlorinated compounds and cryptorchidism; A nested case-control study

Background

Maldescended testes or cryptorchidism is a genital birth defect that affects 2–9% of all male new-borns. Over the last 40 years there have been reports of increased prevalence in countries like the US, the UK and the Scandinavian countries. This possible increase has in some studies been linked to a foetal exposure to chemical pollutants. In this matched case-control study, we analysed maternal serum samples in early pregnancy for three different organochlorine compounds, to investigate whether the levels were associated with the risk of cryptorchidism.

Method

Maternal serum samples taken during the first trimester of pregnancy from 165 cases (boys born with cryptorchidism) and 165 controls, matched for birth year and maternal age, parity and smoking habits during the pregnancy, were retrieved from the Southern Sweden Maternity Biobank. The samples were analysed for 2,2’,4,4’,5,5’-hexachlorobiphenyl (PCB-153), dichlorodiphenyltrichloroethane (p,p’-DDE) and hexachlorobenzene (HCB), using gas chromatography mass spectrometry. Associations between exposure and cryptorchidism were evaluated by conditional logistic regression.

Results

We found no statistically significantly associations between exposure to these compounds and cryptorchidism, either when the exposure variables were used as a continuous variable, or when the exposure levels were divided in quartiles.

Conclusion

We found no evidence of an association between maternal levels of PCB-153, p,p’-DDE or HCB during the pregnancy and the risk of having cryptorchidism in the sons.

Use of stored serum in the study of time trends and geographical differences in exposure of pregnant women to phthalates

BACKGROUND

Exposure to some phthalate diesters has been associated with adverse reproductive health outcomes in both rodents and humans indicative of anti-androgenic effects. Exposure during sensitive periods of development, such as prenatally, is of particular concern.

OBJECTIVES

We wished to investigate whether phthalate metabolites measured in maternal serum samples from historical birth cohorts can be used to assess prenatal exposure. Further, we aimed to study temporal and geographical trends in phthalate exposure across three different birth cohorts.

METHODS

We compared phthalate metabolite levels in maternal serum samples from an Australian (1989-91) and a Danish (1997-2001) birth cohort with levels in serum and urine samples from a recent Danish birth cohort (2012-14). Samples were analysed for 32 phthalate metabolites from 15 phthalate diesters by isotope-diluted liquid chromatography-tandem mass spectrometry (LC-MS/MS). Correlations between metabolites were tested by Spearman rank correlation test, and differences between the cohorts were tested by Mann-Whitney U test.

RESULTS

Overall, we observed large variations in serum phthalate metabolite levels between individuals. Secondary metabolites of di-(2-ethyl-hexyl) phthalate (DEHP) and di-iso-nonyl phthalate (DiNP) in serum were weakly to moderately and positively correlated to the levels measured in urine, and secondary metabolites of DEHP were also moderately to strongly and significantly correlated in serum. Correlations with mono-(2-ethyl-hexyl) phthalate (MEHP) and mono-iso-nonyl phthalate (MiNP), the two primary metabolites of DEHP and DiNP, were inconsistent, and we found indications of sample contamination. We observed some significant differences in phthalate metabolite levels between the three cohorts with generally higher levels in the older birth cohorts.

CONCLUSION

Based on comparison across two older birth cohorts and a recent cohort, our results support the concept that historical biobanked serum samples may be used for assessment of prenatal exposure to phthalates when using serum levels of the monoesters of the low-molecular weight (LMW) phthalates and the secondary metabolites of the high-molecular weight (HMW) phthalates. Serum phthalate measurements are, however, not suitable for human biomonitoring and should only be used to exploit historical samples from cohorts, where urine samples were not collected. Our findings suggest that phthalate exposure may have decreased over time from the early 1990s to the 2010s.

Semen quality of young men in Switzerland: a nationwide cross-sectional population-based study

BACKGROUND

Sperm counts have been steadily decreasing over the past five decades with regional differences in the Western world. The reasons behind these trends are complex, but numerous insights indicate that environmental and lifestyle factors are important players.

OBJECTIVE

To evaluate semen quality and male reproductive health in Switzerland.

MATERIALS AND METHODS

A nationwide cross-sectional study was conducted on 2523 young men coming from all regions of Switzerland, recruited during military conscription. Semen volume, sperm concentration, motility, and morphology were analyzed. Anatomy of the genital area and testicular volume was recorded. Testicular cancer incidence rates in the general population were retrieved from Swiss regional registries.

RESULTS

Median sperm concentration adjusted for period of sexual abstinence was 48 million/mL. Comparing with the 5th percentile of the WHO reference values for fertile men, 17% of men had sperm concentration below 15 million/mL, 25% had less than 40% motile spermatozoa, and 43% had less than 4% normal forms. Disparities in semen quality among geographic regions, urbanization rates, and linguistic areas were limited. A larger proportion of men with poor semen quality had been exposed in utero to maternal smoking. Furthermore, testicular cancer incidence rates in the Swiss general population increased significantly between 1980 and 2014.

DISCUSSION

For the first time, a systematic sampling among young men has confirmed that semen quality is affected on a national level. The median sperm concentration measured is among the lowest observed in Europe. No specific geographical differences could be identified. Further studies are needed to determine to what extent the fertility of Swiss men is compromised and to evaluate the impact of environmental and lifestyle factors.

CONCLUSION

A significant proportion of Swiss young men display suboptimal semen quality with only 38% having sperm concentration, motility, and morphology values that met WHO semen reference criteria.

Lipidomic profiles disturbed by the internet gaming disorder in young Korean males

Internet Gaming Disorder (IGD) is characterized by uncontrollable and persistent playing of internet games despite the occurrence of negative consequences. Although there is a worldwide treatment demand, IGD still doesn't have an explicit biomarker. The primary goal of the study is to characterize lipidomic profiles specific to internet gaming disorder (IGD) based on liquid-chromatography Orbitrap mass-spectrometry (LC Orbitrap MS). Primarily, a total of 19 lipids were significantly dys-regulated in the IGD group compared to healthy controls. The lipidomic feature was mainly characterized by various types of phosphatidylcholines (PCs) and lyso-phosphatidylcholines (LysoPCs). Subsequent multivariate statistical model and linear regression model prioritized two LysoPCs (C16:0 and C18:0) for potential biomarker. Receiver operating characteristic (ROC) analysis demonstrated excellent performance of the combined lipid set for discriminating the IGD group from healthy controls (AUC: 0.981, 95% confidence interval: 0.958-1.000). Additional evaluation with potential confounders and clinical parameters suggested robustness and potential applicability of the outcome as biomarkers which may aid diagnosis.

Clinical Management of Congenital Hypogonadotropic Hypogonadism

The initiation and maintenance of reproductive capacity in humans is dependent on pulsatile secretion of the hypothalamic hormone GnRH. Congenital hypogonadotropic hypogonadism (CHH) is a rare disorder that results from the failure of the normal episodic GnRH secretion, leading to delayed puberty and infertility. CHH can be associated with an absent sense of smell, also termed Kallmann syndrome, or with other anomalies. CHH is characterized by rich genetic heterogeneity, with mutations in >30 genes identified to date acting either alone or in combination. CHH can be challenging to diagnose, particularly in early adolescence where the clinical picture mirrors that of constitutional delay of growth and puberty. Timely diagnosis and treatment will induce puberty, leading to improved sexual, bone, metabolic, and psychological health. In most cases, patients require lifelong treatment, yet a notable portion of male patients (∼10% to 20%) exhibit a spontaneous recovery of their reproductive function. Finally, fertility can be induced with pulsatile GnRH treatment or gonadotropin regimens in most patients. In summary, this review is a comprehensive synthesis of the current literature available regarding the diagnosis, patient management, and genetic foundations of CHH relative to normal reproductive development.

Identification of in vitro effect of 4-octylphenol on the basal and human chorionic gonadotropin (hCG) stimulated secretion of androgens and superoxide radicals in mouse Leydig cells

The aim of our in vitro study was to assess the potential effect of 4-octylphenol (4-OP) on the basal and human chorionic gonadotropin (hCG)-stimulated cholesterol levels and biosynthesis of steroid hormones in cultured mouse Leydig cells. In addition, we evaluated the intracellular superoxide production following 4-OP treatment. Isolated mouse Leydig cells were cultured in the presence or absence of 1 IU/mL (hCG) with the addition of 0.04; 0.2; 1.0; 2.5 and 5.0 µg/mL 4-OP during 44 h. The level of cholesterol was determined from the culture medium using photometry. Quantification of steroid hormones was performed by the enzyme linked immunosorbent assay and intracellular generation of superoxide radicals was assessed by the nitroblue-tetrazolium assay. Administered concentrations of 4-OP (0.04-5.0 µg/mL) did not affect basal and hCG-stimulated cholesterol level significantly. However, basal DHEA secretion was increased significantly (P < 0.001) in the highest experimental dose (5 µg/mL) of 4-OP. By hCG-stimulated DHEA secretion, a significant (P < 0.001) decrease was recorded at 5.0 µg/mL 4-OP in comparison to the control group. The stimulatory effect of 4-OP was also confirmed in androstenedione secretion, when 2.5 and 5.0 µg/mL increased hormone secretion significantly (P˂0.05; P˂0.001). Exposure to experimental concentrations (0.04 to 5.0 µg/mL) of tested chemical reduced hCG-stimulated androstenedione formation, but not significantly. Measurements of basal testosterone production have shown significant (P˂0.01; P˂0.001) increase at 1.0; 2.5 and 5.0 µg/mL of 4-OP. Furthermore, 44 h treatment by 4-OP (1.0-5.0 µg/mL) caused significant (P˂0.01; P˂0.001) intracellular accumulation of superoxide radicals in exposed cells. A considerably more detailed and systematic research is required for a better understanding of risks associated with male reproductive system in humans and wildlife.