Socio-occupational class, region of birth and maternal age: influence on time to detection of cryptorchidism (undescended testes): a Danish nationwide register study

Maternal exposure to airborne polychlorinated biphenyls (PCBs) and risk of adverse birth outcomes

Human health effects of airborne lower-chlorinated polychlorinated biphenyls (LC-PCBs) are largely unexplored. Since PCBs may cross the placenta, maternal exposure could potentially have negative consequences for fetal development. We aimed to determine if exposure to airborne PCB during pregnancy was associated with adverse birth outcomes. In this cohort study, exposed women had lived in PCB contaminated apartments at least one year during the 3.6 years before conception or the entire first trimester of pregnancy. The women and their children were followed for birth outcomes in Danish health registers. Logistic regression was performed to estimate odds ratios (OR) for changes in secondary sex ratio, preterm birth, major congenital malformations, cryptorchidism, and being born small for gestational age. We performed linear regression to estimate difference in birth weight among children of exposed and unexposed mothers. All models were adjusted for maternal age, educational level, ethnicity, and calendar time. We identified 885 exposed pregnancies and 3327 unexposed pregnancies. Relative to unexposed women, exposed women had OR 0.97 (95% CI 0.82, 1.15) for secondary sex ratio, OR 1.13 (95% CI 0.76, 1.67) for preterm birth, OR 1.28 (95% CI 0.81, 2.01) for having a child with major malformations, OR 1.73 (95% CI 1.01, 2.95) for cryptorchidism and OR 1.23 (95% CI 0.88, 1.72) for giving birth to a child born small for gestational age. The difference in birth weight for children of exposed compared to unexposed women was − 32 g (95% CI—79, 14). We observed an increased risk of cryptorchidism among boys after maternal airborne LC-PCB exposure, but due to the proxy measure of exposure, inability to perform dose–response analyses, and the lack of comparable literature, larger cohort studies with direct measures of exposure are needed to investigate the safety of airborne LC-PCB exposure during pregnancy

Effects of the prenatal environment on cryptorchidism: A narrative review

Cryptorchidism, the absence of testes from the scrotum, is the most common genital disorder in boys and a risk factor for reduced fertility and testicular cancer. The mechanism responsible for cryptorchidism involves two discrete stages: a transabdominal and an inguinoscrotal phase. These phases of testicular descent are regulated by the prenatal sex hormone environment, including levels of testosterone, insulin-like factor 3, and calcitonin gene-related peptide. Environmental endocrine disruptors, which are unfavorable environmental factors, may also affect testicular descent through prenatal sex hormones. This review examined the effects of environmental factors, particularly environmental endocrine disruptors, such as phthalates, organochlorine pesticides, diethylstilbestrol, bisphenol A, dioxins/dioxin-like compounds, and perfluoroalkyl substances, and parental lifestyles on the risk of cryptorchidism. Although some studies have shown that environmental endocrine disruptors can affect testicular descent by changing the hormonal environment during the prenatal period, no significant association has been established between exposure to environmental endocrine disruptors and the incidence of cryptorchidism. Therefore, the role played by environmental endocrine disruptor exposure (if any) in the pathogenesis of cryptorchidism remains unknown. Further studies are needed to examine these issues.

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.

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.

Family and neighborhood socioeconomic inequality in cryptorchidism and hypospadias: A nationwide study from Sweden

OBJECTIVES

To examine whether there is an association between neighborhood deprivation and incidence of cryptorchidism and hypospadias, after accounting for family-level and individual-level sociodemographic characteristics.

METHODS

All boys born in Sweden between January 1, 2001 and December 31, 2010 were followed. Data were analyzed by multilevel logistic regression, with family-level and individual-level characteristics at the first level and level of neighborhood deprivation at the second level.

RESULTS

During the study period, among a total of 497,584 boys, 8,584 (1.7%) and 3,704 (0.7%) were diagnosed with cryptorchidism and hypospadias, respectively. Cumulative rates for cryptorchidism and hypospadias increased with increasing levels of neighborhood deprivation. In the study population, 1.5 per 100 and 2.0 per 100 boys, in the least and most deprived neighborhoods were diagnosed with cryptorchidism and 0.7 per 100 and 0.9 per 100 boys were diagnosed with hypospadias. Incidence of hospitalization for cryptorchidism and hypospadias increased with increasing neighborhood-level deprivation across all family-level and individual-level sociodemographic categories. The odds ratio (OR) for cryptorchidism and hypospadias for those living in high-deprivation neighborhoods versus those living in low-deprivation neighborhoods was 1.13 (95% confidence interval [CI] = 1.05-1.21) and 1.24 (95% CI = 1.12-1.37). High neighborhood deprivation remained significantly associated with higher odds of hypospadias after adjustment for family-level and individual-level sociodemographic characteristics (OR = 1.20, 95% CI = 1.08-1.35).

CONCLUSIONS

This study is the largest so far on neighborhood influences on cryptorchidism and hypospadias. Our results suggest that neighborhood deprivation is associated with a moderate incidence of hypospadias independent of family-level and individual-level sociodemographic characteristics.

Perfluorooctane Sulfonate Concentrations in Amniotic Fluid, Biomarkers of Fetal Leydig Cell Function, and Cryptorchidism and Hypospadias in Danish Boys (1980-1996)

BACKGROUND

Exposure to perfluorooctane sulfonate (PFOS) may potentially disturb fetal Leydig cell hormone production and male genital development.

OBJECTIVES

We aimed to study the associations between levels of amniotic fluid PFOS, fetal steroid hormone, and insulin-like factor 3 (INSL3) and the prevalence of cryptorchidism and hypospadias.

METHODS

Using the Danish National Patient Registry, we selected 270 cryptorchidism cases, 75 hypospadias cases, and 300 controls with stored maternal amniotic fluid samples available in a Danish pregnancy-screening biobank (1980-1996). We used mass spectrometry to measure PFOS in amniotic fluid from 645 persons and steroid hormones in samples from 545 persons. INSL3 was measured by immunoassay from 475 persons. Associations between PFOS concentration in amniotic fluid, hormone levels, and genital malformations were assessed by confounder-adjusted linear and logistic regression.

RESULTS

The highest tertile of PFOS exposure (> 1.4 ng/mL) in amniotic fluid was associated with a 40% (95% CI: -69, -11%) lower INSL3 level and an 18% (95% CI: 7, 29%) higher testosterone level compared with the lowest tertile (< 0.8 ng/mL). Amniotic fluid PFOS concentration was not associated with cryptorchidism or hypospadias.

CONCLUSIONS

Environmental PFOS exposure was associated with steroid hormone and INSL3 concentrations in amniotic fluid, but was not associated with cryptorchidism or hypospadias in our study population. Additional studies are needed to determine whether associations with fetal hormone levels may have long-term implications for reproductive health.

CITATION

Toft G, Jönsson BA, Bonde JP, Nørgaard-Pedersen B, Hougaard DM, Cohen A, Lindh CH, Ivell R, Anand-Ivell R, Lindhard MS. 2016. Perfluorooctane sulfonate concentrations in amniotic fluid, biomarkers of fetal Leydig cell function, and cryptorchidism and hypospadias in Danish boys (1980-1996). Environ Health Perspect 124:151-156; http://dx.doi.org/10.1289/ehp.1409288.