The cryptorchidism prevalence among infants in the general population of Rotterdam, the Netherlands

Fetal Renal Duplicated Collecting System at 14-16 Weeks of Gestation

(1) Background: To examine the incidence of the prenatal diagnosis of the renal double-collecting system (rDCS) and describe its clinical outcome and associated genetic abnormalities. (2) Methods: This retrospective study included women who attended the obstetric clinic for early fetal anatomic sonography with findings of a renal DCS. Diagnosis was conducted by an expert sonographer using defined criteria. (3) Results: In total, 29,268 women underwent early ultrasound anatomical screening at 14-16 weeks, and 383 cases of rDCS were diagnosed (prevalence: 1:76). Associated abnormalities were diagnosed in eleven pregnancies; four had chromosomal aberrations. No chromosomal abnormalities were reported in isolated cases. Ectopic uretrocele and dysplastic kidney were diagnosed in 6 (1.5%) and 5 (1.3%) fetuses, respectively. One girl was diagnosed with vesicoureteral reflux and recurrent UTIs, and two boys were diagnosed with undescended testis. The recurrence rate of rDCS was 8% in subsequent pregnancies. (4) Conclusions: In light of its benign nature, we speculate that isolated rDCS may be considered a benign anatomic variant, but a repeat examination in the third trimester is recommended to assess hydronephrosis.

Associations of maternal urinary bisphenol and phthalate concentrations with offspring reproductive development

Fetal exposure to bisphenols and phthalates may influence development of the reproductive system. In a population-based, prospective cohort study of 1059 mother-child pairs, we examined the associations of maternal gestational urinary bisphenols and phthalates concentrations with offspring reproductive development from infancy until 13 years. We measured urinary bisphenol and phthalate concentrations in each trimester. We obtained information on cryptorchidism or hypospadias after birth from medical records. At 9.7 years, we measured testicular and ovarian volume by MRI. At 13.5 years, we measured child Tanner stages and menstruation through questionnaire. We performed linear or logistic regression models for boys and girls to assess the associations of maternal urinary average and trimester-specific bisphenols and phthalates with child reproductive outcomes. Next, to further explore potential synergistic or additive effects of exposures together, we performed mixed exposure models using a quantile g computation approach. Models were adjusted for maternal age, ethnicity, body-mass index, education, parity, energy intake, smoking and alcohol use, and child's gestational age at birth, birthweight and body-mass index. In boys, no associations of maternal gestational phthalate or bisphenol with offspring cryptorchidism and hypospadias were found. Higher maternal high-molecular-weight phthalate and total bisphenol, but not phthalic acid or low-molecular-weight phthalate, were associated with larger child testicular volume at 10 years. Higher maternal phthalic acid and total bisphenol were associated with earlier genital and pubic hair development at 13 years, respectively (p-values<0.05). In girls, we found no associations of maternal urinary bisphenol and phthalate with ovarian volume or menstrual age. Only higher maternal urinary high-molecular-weight phthalate was associated with earlier pubic hair development at 13 years (p-values <0.05). Higher mixture exposure was associated with earlier pubic hair development in both sexes. In conclusion, higher maternal gestational urinary bisphenol and phthalate concentrations were associated with alterations in offspring reproductive development, mainly in boys.

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.

Incidence and prevalence of congenital anomalies in low- and middle-income countries: A systematic review

BACKGROUND

In the absence of robust data from low- and middle-income countries (LMICs), most disease burden estimates and related resource allocation choices are based on historic Northern demographics. We hypothesize that significant discrepancies exist between directly reported LMIC data and surrogate high-income country (HIC) disease burden estimates of correctible congenital anomalies.

METHODS

Nine online databases were searched for studies reporting incidence and prevalence data on surgically correctible congenital anomalies in LMICs between 2006 and 2017. Two independent reviewers screened titles and abstracts, with a third adjudicating discrepancies. Selected studies were reviewed and analyzed.

RESULTS

Of 10,128 identified articles, 98 were extracted for full-text review, and 41 were included, representing 21 LMICs and 18 conditions. Study types included community surveys (34%), prospective (22%) and retrospective (17%) multi-site data, registries (12%), single-site data (12%), and systematic reviews (5%). Data collection periods were 1 to 10 years. The pooled epidemiologic data varied systematically from existing HIC literature, with the incidence of disease being generally lower in LMICs.

CONCLUSIONS

Marked discrepancies exist between reported epidemiological data in LMICs and HIC literature, in part owing to varying quality of data collection in LMICs. Robust population-based surveys are needed to accurately estimate the burden of surgically correctable congenital anomalies in LMICs.

LEVEL OF EVIDENCE

Level V, expert opinion without explicit critical appraisal.

Secular trends in the incidence and timing of surgical intervention for congenital undescended testis and surgically treated hypospadias in Ontario, Canada between 1997 and 2007

INTRODUCTION

Recent studies have suggested contradictory trends in the incidence of undescended testis (UDT) and hypospadias (HYP), partly because of methodological issues and ascertainment bias. The recently described association of "testicular dysgenesis syndrome" links concomitant UDT and HYP, with decreasing sperm counts and testicular cancer. Current guidelines suggest that orchidopexy for UDT should be performed by 18 months of age.

OBJECTIVE

We conducted a retrospective population-based cohort study to estimate the incidence of UDT, HYP, and concomitant UDT and HYP in Ontario, based on a surgical procedure performed in the 5 years after birth. We hypothesized that the incidence of UDT and HYP are stable in the province of Ontario, Canada, over an 11-year time period.

STUDY DESIGN

Linked administrative databases held at the Institute of Clinical Evaluative Sciences (ICES) in the province of Ontario, were used to identify all live male newborns between 1997 and 2007. Incidence rates of UDT, HYP and concomitant UDT and HYP were calculated by identifying a surgical procedure for these anomalies, within 5 years of birth. Incidence trends were analyzed using the Cochrane Armitage test for trend. Age at surgery for surgical intervention for an orchidopexy or HYP repair was determined.

RESULTS

The incidence of UDT, defined by an orchidopexy within 5 years of birth, has remained stable in Ontario, Canada (8.2/1000 male live births, p-value for trend 0.9, 95% CI 8.0-8.4). The incidence of hypospadias has similarly remained stable (3.8/1000 male live births, p-value for trend 0.8, 95% CI 3.7-3.9). The incidence of concomitant UDT and HYP repair showed a significant increase over the 11-year period (0.2/1000 male live births, p-value for trend 0.03, 95% CI 0.2-0.3). The median age at orchidopexy (23 months, IQR 16-34 months) was beyond guideline recommendations, with earlier orchidopexy in recent years. The median age at hypospadias repair was 17 months (IQR 12-26 months).

DISCUSSION

The variable rates of incidence for UDT and HYP can be explained by variations in study methodology and differing data sources utilized. The current study uses a surgical procedure to minimize information bias to correctly identify index cases of UDT and HYP.

CONCLUSIONS

The incidence of undescended testis and hypospadias, over 5 years after birth, has remained stable in the province of Ontario between 1997 and 2007 (Summary Table). Concomitant UDT and HYP incidence showed a significant increase over this time period. Most boys in Ontario, Canada, undergo orchidopexy beyond 18 months of age.

A Brief Review of the Link between Environment and Male Reproductive Health: Lessons from Studies of Testicular Germ Cell Cancer

During the past few decades there has been a significantly increasing trend in germ cell tumours all over the world, particularly in countries with Caucasian populations. The changes in incidence have occurred so fast that only environmental factors can explain this development. This review focuses on the hypothesis that testicular germ cell cancer, which originates from germ cell neoplasia in situ, is of foetal origin and associated with other male reproductive problems through a testicular dysgenesis syndrome, also including foetal origin of impaired spermatogenesis, hypospadias and cryptorchidism. There is little doubt that environmental factors associated with modern lifestyles have - in a broad sense - had an adverse influence on male reproductive health. The hypothesis that exposure to endocrine-disrupting chemicals plays a fundamental role in this trend is plausible. This is based on evidence from animal studies that demonstrate adverse reproductive effects caused by a number of endocrine-disrupting chemicals to which humans are exposed as part of our modern lifestyle.

Risk factors for cryptorchidism

Undescended testis - known as cryptorchidism - is one of the most common congenital abnormalities observed in boys, and is one of the few known risk factors for testicular cancer. The key factors that contribute to the occurrence of cryptorchidism remain elusive. Testicular descent is thought to occur during two hormonally-controlled phases in fetal development - between 8-15 weeks (the first phase of decent) and 25-35 weeks gestation (the second phase of descent); the failure of a testis to descend permanently is probably caused by disruptions to one or both of these phases, but the causes and mechanisms of such disruptions are still unclear. A broad range of putative risk factors have been evaluated in relation to the development of cryptorchidism but their plausibility is still in question. Consistent evidence of an association with cryptorchidism exists for only a few factors, and in those cases in which evidence seems unequivocal the factor is likely to be a surrogate for the true causal exposure. The relative importance of each risk factor could vary considerably between mother-son pairs depending on an array of genetic, maternal, placental and fetal factors - all of which could vary between regions. Thus, the role of causative factors in aetiology of cryptorchidism requires further research.

Identification of six novel mutations in ZEB1 and description of the associated phenotypes in patients with posterior polymorphous corneal dystrophy 3

Posterior polymorphous corneal dystrophy 3 (PPCD3) is a rare autosomal dominant disorder caused by mutations in ZEB1. To date all identified disease-causing variants were unique to the studied families, except for c.1576dup. We have detected six novel ZEB1 mutations; c.1749_1750del; p.(Pro584*) and c.1717_1718del; p.(Val573Phefs*12) in two Czech families, c.1176dup; p.(Ala393Serfs*19), c.1100C>A; p.(Ser367*), c.627del; p.(Phe209Leufs*11) in three British families and a splice site mutation, c.685-2A>G, in a patient of Sri Lankan origin. An additional British proband had the c.1576dup; p.(Val526Glyfs*3) mutation previously reported in other populations. Clinical findings were variable and included bilateral congenital corneal opacity in one proband, development of opacity before the age of 2 years in another individual and bilateral iris flocculi in yet another subject. The majority of eyes examined by corneal topography (10 out of 16) had an abnormally steep cornea (flat keratometry 46.5-52.7 diopters, steep keratometry 48.1-54.0 diopters). One proband underwent surgery for cryptorchidism. Our study further demonstrates that PPCD3 can present as corneal edema in early childhood, and that an abnormally steep keratometry is a common feature of this condition. As cryptorchidism has been previously observed in two other PPCD3 cases, its association with the disease warrants further investigation.

Do ethnic patterns in cryptorchidism reflect those found in testicular cancer?

PURPOSE

There are established variations in testicular cancer incidence between ethnic groups within countries. It is currently unclear whether the occurrence of cryptorchidism-a known risk factor for testicular cancer-follows similar patterns. In New Zealand Māori have unusually high rates of testicular cancer compared to individuals of European ancestry. We hypothesized that ethnic trends in the incidence of cryptorchidism would reflect those for testicular cancer in this setting.

MATERIALS AND METHODS

We followed 318,441 eligible male neonates born in New Zealand between 2000 and 2010 for the incidence of orchiopexy confirmed cryptorchidism and the incidence of known risk factors for cryptorchidism (low birth weight, short gestation, small size for gestational age) using routine maternity, hospitalization and mortality records. Logistic regression was used to calculate odds ratios for the presence of known risk factors for cryptorchidism by ethnic group. Poisson regression was used to calculate relative risk of cryptorchidism by ethnicity, adjusted for risk factors.

RESULTS

Ethnic patterns of cryptorchidism incidence in New Zealand closely mirrored those previously observed for testicular cancer. Māori had higher rates of cryptorchidism than all other ethnic groups (adjusted RR 1.2 [95% CI 1.11-1.3]), with Pacific (0.89 [0.8-0.99]) and Asian groups (0.68 [0.59-0.79]) having the lowest rates (European/other, referent).

CONCLUSIONS

Since the principal risk factors for cryptorchidism are present in utero, the results of the current study strengthen the likelihood that the ethnic patterning of testicular cancer is at least partly due to prenatal risk factors.

Intrauterine exposure to mild analgesics during pregnancy and the occurrence of cryptorchidism and hypospadia in the offspring: the Generation R Study

BACKGROUND

Recently, over-the-counter mild analgesic use during pregnancy has been suggested to influence the risk of reproductive disorders in the offspring. We examined the influence of maternal exposure to mild analgesics during pregnancy on the occurrence of cryptorchidism and hypospadia in their offspring.

METHODS

Associations between maternal exposure to mild analgesics during pregnancy and cryptorchidism or hypospadia in the offspring were studied in 3184 women participating in a large population-based prospective birth cohort study from early pregnancy onwards in the Netherlands (2002-2006), the Generation R Study. Cryptorchidism and hypospadia were identified during routine screening assessments performed in child health care centres by trained physicians. The use of mild analgesics was assessed in three prenatal questionnaires in pregnancy, resulting in four periods of use, namely, periconception period, first 14 weeks of gestation, 14-22 weeks of gestation and 20-32 weeks of gestation. Logistic regression analyses were used to study the associations between maternal exposure to mild analgesics and cryptorchidism and hypospadia.

RESULTS

The cumulative prevalence over 30 months of follow up was 2.1% for cryptorchidism and 0.7% for hypospadia. Use of mild analgesics in the second period of pregnancy (14-22 weeks) increased the risk of congenital cryptorchidism [adjusted odds ratio (OR) 2.12; 95% confidence interval (CI) 1.17-3.83], primarily due to the use of acetaminophen (paracetamol) (adjusted OR 1.89; 95% CI 1.01-3.51). Among mothers of cryptorchid sons, 33.8% reported (23 of 68) the use of mild analgesics during pregnancy, compared with 31.8% (7 of 22) of mothers with a boy with hypospadia and 29.9% (926 of 3094) of mothers with healthy boys.

CONCLUSIONS

Our results suggest that intrauterine exposure to mild analgesics, primarily paracetamol, during the period in pregnancy when male sexual differentiation takes place, increases the risk of cryptorchidism.

Risk factors for undescended testis

OBJECTIVE

To contribute to the understanding of the etiology of undescended testis (UDT), by exploring a wide range of potential risk factors in a case-referent study.

PATIENTS AND METHODS

Cases and referents were recruited at five hospitals and included 200 boys with surgically corrected UDT and 629 boys with persistent middle ear effusion. Risk factor data were obtained by postal questionnaires to both parents. Clinical data were collected from medical files. Adjusted odds ratios (OR) with 95% confidence intervals (CI) were estimated using logistic regression.

RESULTS

The main findings include associations between UDT and familial occurrence of the disorder: OR 3.1 (95%CI 1.9-4.9), low birth weight: 2.2 (1.1-4.3), twinning: 2.2 (0.9-5.4), gestational preeclampsia: 1.9 (0.8-4.4), use of oral contraceptives after conception: 3.6 (1.0-12.5), in vitro fertilization/intracytoplasmic sperm injection treatment: 2.2 (0.8-6.0), paternal subfertility: 1.8 (0.8-4.1), and maternal occupational exposure to cosmetics: 3.0 (0.9-10.0). Subgroup analyses indicated differences in ORs for several factors between cases with (n = 92) and without (n = 103) inguinal hernia or hydrocele.

CONCLUSION

The findings point towards a role for genetic predisposition, placental insufficiency, and possibly exposure to specific endocrine disrupting substances in the etiology of UDT. Further research should take into account potential etiologic differences between subgroups of cases with UDT.

Prenatal environmental risk factors for genital malformations in a population of 1442 French male newborns: a nested case-control study

BACKGROUND

Over the past decades, an increasing trend in male external genital malformations such as cryptorchidism and hypospadias has led to the suspicion that environmental chemicals are detrimental to male fetal sexual development. Several environmental pollutants, including organochlorine pesticides, polychlorinated biphenyls, bisphenol A, phthalates, dioxins and furans have estrogenic and anti-androgenic activity and are thus considered as endocrine-disrupting chemicals (EDCs). Since male sex differentiation is critically dependent on the normal production and action of androgens during fetal life, EDCs may be able to alter normal male sex differentiation.

OBJECTIVE

The objective of this study was to determine the incidence of external genital malformations in a population of full-term newborn males in southern France. We also performed a case-control study to identify the risk factors for male external genital malformations, with a focus on parental occupational exposure to EDCs.

METHODS

Over a 16-month period, 1615 full-term newborn males with a birth weight above 2500 g were registered on a level-1 maternity ward, and the same pediatrician systematically examined 1442 of them (89%) for cryptorchidism, hypospadias and micropenis. For every male newborn with genital malformation, we enrolled nearly two males matched for age, parity and term. All parents of the case and control newborns were interviewed about pregnancy aspects, personal characteristics, lifestyle and their occupational exposure to EDCs using a detailed questionnaire. RESULTS We report 39 cases of genital malformation (2.70%), with 18 cases of cryptorchidism (1.25%), 14 of hypospadias (0.97%), 5 of micropenis (0.35%) and 2 of 46,XY disorders of sexual differentiation (DSD; 0.14%). We observed a significant relationship between newborn cryptorchidism, hypospadias or micropenis and parental occupational exposure to pesticides [odds ratio (OR) = 4.41; 95% confidence interval (95% CI), 1.21-16.00]. Familial clustering for male external genital malformations (OR = 7.25; 95% CI, 0.70-74.30) and medications taken by mothers during pregnancy (OR = 5.87; 95% CI, 0.93-37.00) were associated with the risk of cryptorchidism, hypospadias and micropenis, although the association was not statistically significant.

CONCLUSIONS

Although the causes of male genital malformation are multifactorial, our data support the hypothesis that prenatal contamination by pesticides may be a potential risk factor for newborn male external genital malformation and it should thus be routinely investigated in all undervirilized newborn males.

Prospective study on the prevalence and associated risk factors of cryptorchidism in 6246 newborn boys from Nice area, France

To assess the incidence and risk factors of cryptorchidism in Nice area. A 3-year prospective study was conducted at two maternity wards involving neonatal screening of boys born ≥34weeks of amenorrhoea. Methodology was strict with examination at birth, 3 and 12months by the same paediatrician. Two strictly matched controls were included for each case. Information on child and parents (medical history, pregnancy, lifestyle) was recorded using medical chart and self-administered questionnaires. A total of 102 of 6246 boys were born with cryptorchidism (prevalence 1.6%, 95 included). Half of them were still cryptorchid at three and 12months with, however, 10% of secondary re-ascent (recurrent cryptorchidism) at 12months, justifying long-term follow-up. Cryptorchidism at birth was associated with instrumental delivery, inguinal hernia and urogenital malformations, particularly micropenis and paternal history of cryptorchidism. Our results suggest that maternal exposure to anti-rust or phthalates could be a risk factor, whereas eating fruits daily seemed somewhat protective. Prevalence of cryptorchidism in our area is on the lower bracket compared with other countries, and is associated with both familial and environmental risk factors.

Les différentes anomalies de la reproduction masculine sont-elles en augmentation ? Faits et controverses, possibles facteurs en cause: une analyse actualisée des données de la littérature et des registres

Au cours des dernières décennies, de nombreuses observations dans la faune sauvage d’anomalies relatives à l’appareil génital et à la fonction de reproduction mâle, certaines évoquant les données de la toxicologie expérimentale, ont conduit à s’interroger sur la toxicité de facteurs environnementaux pour la reproduction de l’homme. De plus, un certain nombre d’études suggère une augmentation de la prévalence des troubles de la reproduction de l’homme adulte au cours des dernières décennies dans de nombreux pays développés. Les données les mieux documentées concernent le cancer du testicule, son rythme de croissance suggérant le rôle de facteurs environnementaux et/ou de mode de vie. Toutefois, des différences régionales et ethniques considérables dans les taux d’incidence absolue pourraient impliquer des facteurs génétiques concomitants. Parallèlement, il semble que la qualité du sperme a diminué dans de nombreux pays, à en juger aussi bien par des méta-analyses que par des analyses statistiques de données d’un seul centre. Au début des années 2000, Skakkebæk et al. à Copenhague ont formulé l’hypothèse d’une origine commune à ces différentes anomalies lors du développement du testicule durant la gestation. Existe-t-il pour ces différentes conditions des données indiquant un lien de causalité avec une exposition environnementale/professionnelle à des composés reprotoxiques ? Ne serait-ce plutôt l’exposition chronique à de très nombreux composés chimiques à faible dose qui pourrait être impliquée ? Les facteurs de style de vie jouent-ils un rôle ? L’ensemble de ces questions se fondant sur une somme d’études, dont les résultats sont loin d’être univoques, a été la source de nombreux débats aussi bien au sein de la communauté scientifique que dans les médias. Les meilleures réponses possibles à ces questions complexes sont naturellement fondamentales pour les instances en charge de l’évaluation du risque et les politiques de santé publique qu’il convient d’adopter. La présente revue donne un état des lieux actualisé de ces questions.

Genital anomalies in boys and the environment

The prevalence of male reproductive disorders, such as testicular cancer and impaired semen quality, is increasing in many, albeit not all, countries. These disorders are aetiologically linked with congenital cryptorchidism and hypospadias by common factors leading to perinatal disruption of normal testis differentiation, the testicular dysgenesis syndrome (TDS). There is recent evidence that also the prevalence of genital malformations is increasing and the rapid pace of increase suggests that lifestyle factors and exposure to environmental chemicals with endocrine disrupting properties may play a role. Recent prospective studies have established links between perinatal exposure to persistent halogenated compounds and cryptorchidism, as well as between phthalates and anti-androgenic effects in newborns. Maternal alcohol consumption, mild gestational diabetes and nicotine substitutes were also identified as potential risk factors for cryptorchidism. It may be the cocktail effect of many simultaneous exposures that result in adverse effects, especially during foetal life and infancy.

Temporal trends in bull semen quality: a comparative model for human health?

INTRODUCTION

A decline in human semen quality over the past 30-60 years has been reported in numerous epidemiological studies from the United States and Europe. We evaluated temporal trends in semen quality parameters in dairy bulls. The long-term management of dairy bulls for artificial insemination presented a unique opportunity to evaluate temporal trends in semen quality and explore this relationship as a potential animal model for reproductive abnormalities in humans.

MATERIALS AND METHODS

Bull semen analysis data from 1965 through 1995 were collected from a large artificial insemination organization. Semen analyses from 12- to 18-month-old Holstein dairy bulls were included in the study and consisted of daily sperm concentration, daily ejaculate volume, total daily sperm output, percentage of sperm with normal morphology, and percentage of sperm with normal post-thaw motility. Multiple regression analysis, logistic regression, and general linear modeling were used to determine temporal trends over the 30-year period.

RESULTS AND DISCUSSION

Semen quality appears to have declined from 1970 to 1980 or 1985 as manifested by declines in daily ejaculate volume, daily sperm concentration, and total daily sperm output. In contrast, sperm morphology and motility improved over the same period. In approximately 1980 or 1985, depending on the parameter, ejaculate volume, sperm concentration, total sperm, and motility improved. However, normal morphology began to deteriorate during this same period. Methodological inconsistencies over time introduce uncertainty in analyses of temporal trends in semen quality in this and previous human studies. However, changes in technology do not appear to be solely responsible for the temporal trends observed. The source of the decline in semen quality in the bulls studied is unknown. If the decline in semen quality were due to exposure to endocrine disrupting chemicals, then a continued decline or a leveling-off would be expected. Instead, a rise in semen quality was observed during the latter portion of the observation period.

Prevalence of cryptorchidism among Bulgarian boys

BACKGROUND

Cryptorchidism is the most common congenital defect of the male urogenital system. It may be an important cause for male infertility. The data about its prevalence in South-eastern European countries and especially for the Balkan region are still incomplete.

OBJECTIVE

The aim of the present study was to establish the prevalence of the abnormality in the Bulgarian population living in the different areas of the country.

METHODS

In a population-based cross-sectional study in Bulgaria 6200 Caucasian boys (aged under 1 year to 19 years) from five regions of the country were included. One physician examined all children in order to reduce the inter-observer error.

RESULTS

The prevalence of cryptorchidism was 1.52% for the total group. It was 3.2% for boys under one year of age, 2.1% for those between one and ten years and dropped significantly in older boys (0.6%). No regional or seasonal trends were established.

CONCLUSIONS

Our study suggests a relatively higher prevalence of cryptorchidism in Bulgaria for children younger than one year of age, while the overall prevalence is comparable to those reported for other countries. The prevalence of cryptorchidism did not differ significantly from the prevalence reported thirty years ago.

Maternal pregnancy serum level of heptachlor epoxide, hexachlorobenzene, and beta-hexachlorocyclohexane and risk of cryptorchidism in offspring

Prenatal exposure to environmental endocrine disrupters has been postulated to cause adverse effects on male reproductive health. Exposure to organochlorine pesticides with anti-androgenic and estrogenic potency has been shown to interfere with the sex-hormone-dependent process of testicular descent in animal models. We examined the relation between serum levels of the pesticides heptachlor epoxide (HCE), hexachlorobenzene (HCB), and beta-hexachlorocyclohexane (beta-HCCH) in pregnant women, and the occurrence of cryptorchidism in their sons. These three pesticides were previously suggested as risk factors for cryptorchidism. In a nested case-control design, we compared serum levels between mothers of cases (n = 219) and controls (n = 564), selected from the Collaborative Perinatal Project, a US birth cohort study of pregnancies in 1959-1966. The offspring of mothers with HCE levels above the 90th percentile compared to those below the 10th percentile had an adjusted odds ratio of cryptorchidism of 1.2 (95% confidence interval 0.6-2.6); for beta-HCCH the odds ratio was 1.6 (0.7-3.6). For HCB the adjusted odds ratio was near one. These results provide little support for an association of cryptorchidism with exposure to low levels of HCE or HCB. For beta-HCCH the findings were somewhat suggestive of an association but were inconclusive.

Reduction in the number of orchidopexies for cryptorchidism after recognition of acquired undescended testis and implementation of expectative policy

BACKGROUND

Since the mid-1990s, acquired undescended testis has gradually been recognised as a separate entity for which the efficacy of prepubertal surgery has not been univocally been demonstrated. Therefore, in our hospital, orchidopexy was no longer routinely performed for acquired undescended testis.

AIM

To investigate the effect of expectative policy in our hospital on the number of orchidopexies.

METHODS

Two 5-year periods were compared. Period A (1991-1995), in which undescended testis was treated surgically, and period B (2000-2004), in which prepubertal orchidopexy in our hospital was no longer performed for acquired undescended testis. In addition, a comparison was made between the percentage reduction in hospital and national figures.

RESULTS

In period B, the number of orchidopexies in our hospital was reduced by 61.8% (from 387 to 148), mainly in the age group >6 years. Nationally, during the same period, the number of orchidopexies decreased only by 2.4% (from 18 024 to 17 591).

CONCLUSION

The results of this study confirm that recognition of acquired undescended testis is crucial for reducing the high number of (late) orchidopexies.

The frequency of undescended testis from birth to adulthood: a review

We performed a systematic review and critique of the literature on the frequency of undescended testis (UDT) among boys from birth to adolescence. Special attention was given to whether previous testicular position was taken into account to distinguish between congenital and acquired UDT. We searched Medline, Embase, Cinahl and the Cochrane Library. Any study reporting on the frequency of UDT was included. Study population age, number of boys studied, period of examination, primary examiner, area of study, study design, ethnicity, definitions used and previous testicular position were analysed. A total of 46 studies met the inclusion criteria. Twenty-three of the 46 (50%) studies involved newborns. Definitions were described in half of the studies; however, the definitions used were heterogeneous. Previous testis position was described in 11% (5/46) of the studies. At birth, in term and/or birth weight >2.5 kg infants, the UDT rate ranged from 1.0 to 4.6%, and in premature and/or birth weight <2.5 kg infants from 1.1 to 45.3%. At the age of 1 year UDT in term and/or birth weight >2.5 kg infants was seen in 1.0-1.5%, at 6 years in 0.0-2.6%, at 11 years in 0.0-6.6% and at 15 years in 1.6-2.2% of boys. The frequency of UDT shows variable figures in the literature. The actual frequency of acquired UDT essentially remains unclear because of the shortage of studies performed at an older age, and of studies reporting on previous testicular position.

Trends in childhood disease

Child mortality has declined remarkably during the last decades. While neonatal disorders, diarrhoea, pneumonia, and malaria as well as being underweight account for most of the child deaths worldwide, children's health discussions in Europe and the USA focus on other issues such as asthma, neurodevelopmental disorders, male genital malformations, and childhood cancer. There is clear evidence of increasing rates of asthma in various countries during the last decades, although rates in some countries may now have stabilised or even decline as recent UK data indicate. Although an increase in the frequency of neurodevelopmental disorders such as autism and attention deficit disorder has frequently been discussed, the limited data in this field does not justify such a conclusion. While geographic heterogeneity regarding reproductive outcomes is apparent, global trends have not been identified. Interpretation of the available information on asthma, neurodevelopmental disorders and reproductive outcomes is hampered by inconstant diagnostic criteria over place and time and the lack of good and comprehensive population-based surveillance data, which makes it impossible to ascertain trends in actual disease frequency. Data indicate that developed countries have a gradually increasing incidence in leukaemia with a corresponding drop in the incidence of lymphoma. Increases in brain tumour frequency may be related to the development and wide application of new diagnostic capabilities, rather than a true change in the incidence of malignant disease. With a better prognosis for childhood cancer survival, secondary cancers following chemotherapy appear to be increasing. A wide range of environmental factors is thought to have an impact on children's health. These factors include nutrition (protein, vitamins, antioxidants), lifestyle and behaviour choices such as tobacco and alcohol use, parental health, socio-economic status, choice of living environment (urban versus rural, etc.), and parent-sibling behaviour. From the available data, no general conclusions on the contribution of specific chemicals can be drawn.

Disrupted sex differentiation and feminization of man and domestic animals

Genital malformations constitute the most common birth defects in man and domestic animals and occur frequently in males since the participation of many genes is required for sex differentiation to proceed in the male direction. The precise dose, timing, and coordination needed for their expression add to the proneness of various stages in male sex differentiation to external influences. The emerging insight, through the identification of genes involved in the sex differentiation cascade, is that over 85% of sex anomalies in human and domestic animal populations are not attributable to chromosome aberrations or to mutations in a known gene. Since a majority of severely malformed individuals are incapable of reproduction, the high rates of these defects have to be results either of new mutations or of collaboration of environmental factors with genes. Increase in specific malformations in domestic animals often indicates increased concentration of liability genes brought together in the conceptus by inbreeding. However, in human populations where inbreeding is not the norm such increases may reflect environment-induced new mutations or interaction of environmental agents with hormone-sensitive genes. This review summarizes the information currently available on the genetics of major events in male sex differentiation and briefly discusses the collaborative role that environment may play in disrupting different components of this process.