Parental age at birth and biomarkers of fecundity in young Danish men

BACKGROUND

High parental age is associated with adverse birth and genetic outcomes, but little is known about fecundity in male offspring.

OBJECTIVES

We investigated if high parental age at birth was associated with biomarkers of male fecundity in a large population-based sample of young men.

MATERIALS AND METHODS

We conducted a study of 1057 men from the Fetal Programming of Semen Quality (FEPOS) cohort, a sub-cohort of sons born 1998-2000 into the Danish National Birth Cohort. Semen characteristics and reproductive hormone concentrations were measured in samples provided by the men 2017-2019. Testis volume was determined by self-measurement. Data on the parental age was drawn from registers. Adjusted relative difference in percentage with 95% confidence intervals were estimated for each outcome according to pre-specified maternal and paternal age groups (< 30 (reference), 30-34 and ≥ 35) as well as for combinations of parental age groups, using multivariable negative binomial regression models.

RESULTS

We did not observe consistent associations between parental age and biomarkers of fecundity, although sons of mothers ≥ 35 years had lower sperm concentration (-15% (95% CI: -30, 3)) and total sperm count (-10% (95% CI: -25, 9)). The analysis with parental age combinations showed lower sperm concentration with high age of the parents (both ≥ 35 years: -27%, 95% CI: -40, -19) when compared to the reference where both parents were below 30 years.

DISCUSSION AND CONCLUSION

We found no strong association between higher parental age and biomarkers of fecundity in young men. However, we cannot exclude poorer semen characteristics in sons born by older mothers or with high age of both parents.

Association of birth weight with cancer risk: a dose-response meta-analysis and Mendelian randomization study

BACKGROUND

Several articles have shown that birth weight is associated with the risk of many types of cancers. However, the results are inconsistent, and whether the relationship has a causal effect remains unknown.

METHODS

We searched the PubMed and Embase libraries up to March 2021 and selected observational studies reporting the relationship between birth weight and adult-onset cancer risk. Dose-response meta-analysis and two-sample Mendelian randomization (MR) analysis were used to estimate the effect.

RESULT

In our dose-response meta-analysis, six cancers from 46 studies were found to have significant associations with birth weight. (Ovarian cancer: RR: 1.21, 95% CI 1.01-1.44; breast cancer: RR: 1.12, 95% CI 1.08-1.16; colorectal cancer: RR: 1.20, 95% CI 1.01-1.43; endometrial cancer: RR: 0.85, 95% CI 0.78-0.93; prostate cancer: RR: 1.27, 95% CI 1.01-1.61; testicular cancer: RR: 1.21, 95% CI 1.03-1.43). As birth weight increased, the slope of the dose-response curve of breast cancer increased continuously, and the curve of testicular cancer was U-shaped. In the MR study, seven cancers were included. Only invasive mucinous ovarian cancer was found to have a causal effect on birth weight (OR: 0.62; 95% CI 0.39-0.97), while other cancers did not.

CONCLUSIONS

Our findings suggest that birth weight are unlikely to have a casual effect on risk of cancers via the MR analysis, although the dose-response meta-analysis shows that there is a nonlinear relationship between birth weight and breast cancer and testicular cancer. More relevant researches are needed to further investigate their effect.

Caesarean sections, prenatal and postnatal conditions and childhood acute lymphoblastic leukaemia: A case-control study in the State of São Paulo, Brazil

INTRODUCTION

Brazil has high rates of caesarean sections, which has been suggested as a risk factor for acute lymphoblastic leukaemia (ALL). In addition, some pre- and postnatal conditions have been identified as relevant in the etiology of ALL.

OBJECTIVES

Investigate the association of caesarean sections, pre- and postnatal conditions with childhood ALL in the State of São Paulo.

METHODS

Population-based case-control study including children that are below10 years old. Information on study variables was obtained through face to face interviews, through a questionnaire, and the State of São Paulo Declarations of Live Births database. The conditional and unconditional logistic regression approaches were used to calculate the odds ratio (OR) of the associations between caesarean sections, pre- and postnatal conditions with ALL, and 95 % confidence intervals (95 % CI).

RESULTS

We observed a weak and non-statistically significant risk for ALL among children exposed to caesarean sections (unconditional logistic regression OR 1.08; 95 % CI 0.70-1.66; conditional logistic regression OR 1.21; 95 % CI 0.72-2.02), but among children under 3 years old and born through a caesarean sections, the risk of ALL was greater (unconditional logistic regression OR 1.70; 95 % CI 0.69-4.21). A negative association for ALL was observed among children with mothers who reported 12 years of schooling or more (unconditional logistic regression OR 0.34; 95 % CI 0.16-0.69).

CONCLUSIONS

We found a tenuous suggestive association between caesarean sections and childhood ALL. The mother's high level of education showed an inverse association with ALL.

Development and validation of prognostic nomogram for germ cell testicular cancer patients

The purpose of our study was to establish a reliable and practical nomogram based on significant clinical factors to predict the overall survival (OS) and cancer-specific survival (CSS) of patients with germ cell testicular cancer (GCTC). Patients diagnosed with GCTC between 2004 and 2015 were obtained from the SEER database. Nomograms were constructed using the R software to predict the OS and CSS probabilities and the constructed nomograms were validated and calibrated. A total of 22,165 GCTC patients were enrolled in the study, including the training cohort (15,515 patients) and the validation cohort (6,650 patients). In the training cohort, multivariate Cox regression showed that age, race, AJCC stage, SEER stage and surgery were independent prognostic factors for OS, while age, race, AJCC stage, TM stage, SEER stage and radiotherapy were independent prognostic factors for CSS. Based on the above Cox regression results, we constructed prognostic nomograms of OS and CSS in GCTC patients and found that the OS nomograms had higher C-index and AUC compared to TNM stage in the training and validation cohorts. In addition, in the training and external validation cohorts, the calibration curves showed a good consistency between the predicted and actual 3-, 5- and 10-year OS and CSS rates of the nomogram. The current prognostic nomogram can provide a personalized risk assessment for the survival of GCTC patients.

Impact of age, clinical conditions, and lifestyle on routine semen parameters and sperm kinematics

OBJECTIVE

To assess the impact of aging on routine semen and computer-assisted sperm analysis (CASA) motility parameters according to the current World Health Organization guidelines; and to evaluate the effect of obesity and lifestyle (alcohol consumption, cigarette smoking) in older men's semen.

DESIGN

Blind cross-sectional study.

SETTING

Research laboratory and andrology and reproduction laboratory.

PATIENT(S)

A population of 11,706 men.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Semen analysis: routine (semen volume, sperm concentration and count, motility, vitality, morphology, hypo-osmotic swelling test, round and peroxidase-positive cell concentration) and CASA (straight-line velocity, curvilinear velocity, average path velocity, linearity, straightness, beat cross frequency, wobble, amplitude of lateral head displacement, and mean angular displacement) parameters; and body mass index.

RESULT(S)

A negative correlation was found between age and routine semen parameters: volume, sperm count, motility, vitality, total motile spermatozoa and normal-motile spermatozoa, round cell concentration, and hypo-osmotic swelling test values. Several CASA variables (straight-line velocity, curvilinear velocity, average path velocity, beat cross frequency, amplitude of lateral head displacement, and mean angular displacement) were also negatively affected. Using 40 years as a cut-off value, significant differences in most parameters correlated to age. In a selected subpopulation of men unexposed to known fertility-compromising factors, the same evaluations were performed, finding some parameters still decreased. Although obesity exerted a significant deleterious effect on older patients' semen quality, alcohol consumption and cigarette smoking mildly affected it.

CONCLUSION(S)

Male aging, with the contribution of unhealthy conditions, are paramount effectors of sperm quality deterioration.

The association between birth order and childhood brain tumors: a systematic review and meta-analysis

The incidence of childhood brain tumors (CBT) has increased worldwide, likely resulting from the improvements of early diagnostics. We conducted a systematic review and meta-analysis to clarify the association between birth order and CBT. We followed established guidelines to systematically search Ovid Medline, PubMed, and the Cochrane Library for English language studies, published before March 2018. Quality assessment was performed using the Newcastle-Ottawa Scale. Meta-analysis provided pooled risk estimates and their 95% confidence intervals (CIs) for birth order and CBT. We identified 16 case-control studies with a total sample of 32 439 cases and 166 144 controls and three prospective cohort studies (i.e. 4515 incident cases of CBTs among 5 281 558 participants). Compared with first birth order, the meta-odds ratio for second birth order in case-control studies was 1.04 (95% CI: 1.01-1.07), that for third birth order was 0.98 (95% CI: 0.90-1.06), and that for fourth order was 0.85 (95% CI: 0.78-0.92). The meta-hazard ratio for second or higher birth order compared with first birth order in cohort studies was 1.00 (95% CI: 0.96-1.05). We found no association between birth order and CBT in both case-control and cohort study designs; the small association observed for fourth birth order deserves further consideration.

Paternal age and risk of testicular germ cell tumors: a cohort study of 1,000,000 men

Testicular germ cell tumors (TGCT) are the most frequent cancer among young men, with increasing incidence worldwide. Advanced paternal age has been linked to adverse health outcomes in offspring, but reports on the association of paternal age with TGCT are few and inconsistent. We aimed to examine the relationship of paternal age (PAB) at birth with the risk of TGCT and by histologic type: seminoma and non-seminoma. A population-based cohort of 1,056,058 males, examined at ages 16-19 between the years 1980-2011, was linked to the Israel National Cancer Registry to obtain incident TGCT through 2012. We applied multivariable Cox regression. During 16.5 million person-years of follow-up, 1247 incident cases (604 seminomas and 643 non-seminomas) were detected. Increasing PAB was linearly associated with lower risk of TGCT (HR_{per year}  = 0.983, 95% CI: 0.974-0.993, p = 0.001), after adjustment for year of birth, years of education, height, cryptorchidism history and origin, and also with additional adjustment for maternal age at birth (MAB) (HR_{per year}  = 0.980: 0.965-0.995, p = 0.008). The association was stronger for seminoma (HR_{per year}  = 0.968: 0.946-0.989, p = 0.004) and persisted in a subset adjusted for sibship size (HR_{per year}  = 0.950: 0.917-0.983, p = 0.003). In the fully adjusted model, young PAB (15-24 vs. ≥30) was a risk factor for seminoma (HR = 1.41: 1.07-1.85, p = 0.014). In models adjusted for PAB, MAB was not associated with risk of TGCT. In conclusion, our findings suggest that young paternal age is a risk factor of TGCT, especially seminoma. The findings warrant further investigation into the possible impact of young paternal age on their offsprings' testes.

Surge of immune cell formation at birth differs by mode of delivery and infant characteristics-A population-based cohort study

BACKGROUND

Birth by cesarean section is associated with increased risks of immune disorders. We tested whether establishment of immune function at birth relates to mode of delivery, taking other maternal and infant characteristics into account.

METHODS AND FINDINGS

Using a prospectively collected database, we retrieved information on maternal and infant characteristics of 6,014 singleton infants delivered from February to April 2014 in Stockholm, Sweden, with gestational age ≥35 weeks, Apgar scores ≥7, and without congenital malformations or any neonatal morbidity. We linked our data to blood levels of T-cell receptor excision circles (TREC) and κ-deleting recombination excision circles (KREC), determined as part of a neonatal screening program for immune-deficiencies, and representing quantities of newly formed T- and B-lymphocytes. Multivariate logistic regression was used to calculate odds ratios (OR) with 95% confidence intervals (CI) for participants having TREC and KREC levels in the lowest quintile. Multivariate models were adjusted for postnatal age at blood sampling, and included perinatal (mode of delivery, infant sex, gestational age, and birth weight for gestational age), and maternal characteristics (age, parity, BMI, smoking, diabetes, and hypertensive disease). Low TREC was associated with cesarean section before labor (adjusted OR:1.32 [95% CI 1.08-1.62]), male infant sex (aOR:1.60 [1.41-1.83]), preterm birth at 35-36 weeks of gestation (aOR:1.89 [1.21-2.96]) and small for gestational age (aOR:1.67 [1.00-2.79]). Low KREC was associated with male sex (aOR:1.32 [1.15-1.50]), postterm birth at ≥42 weeks (aOR:1.43 [1.13-1.82]) and small for gestational age (aOR:2.89 [1.78-4.69]). Maternal characteristics showed no consistent associations with neonatal levels of either TREC or KREC.

CONCLUSION

Cesarean section before labor was associated with lower T-lymphocyte formation, irrespective of maternal characteristics, pregnancy, and neonatal risk factors. The significance of a reduced birth-related surge in lymphocyte formation for future immune function and health remains to be investigated.

Germ Cell Testicular Cancer Incidence, Latitude and Sunlight Associations in the United States and Australia

International patterns suggest germ cell testicular cancer (GCTC) incidence may be lower in lower latitudes. To investigate this possibility, we examined GCTC incidence by latitude (population centroid in 2000) for men ≥15 years within two reasonably homogeneous countries, the United States and Australia. In the United States, we examined age-adjusted incidence/latitude trends using data from states (2001-2010) and local-area registries (1980-2011). In Australia, we evaluated incidence/latitude trends in 61 Statistical Divisions (2000-2009). In U.S. White men (68 566 cases), state incidences increased by latitude, rising 5.74% (4.45-7.05%) per 5°North latitude increment. Similar trends were found for seminoma and nonseminoma subtypes (P < 0.001). In U.S. Black men (2256 cases), the association was also seen (4.9%; 0.2-9.7%). In local U.S. data, similar increases in incidence with latitude were present in each of the last three decades. In Australia (6042 cases), the incidence increased by 4.43% (95% CI: 1.54-7.39%) per 5°South, and trends for subtypes were similar. Thus, we found that incidence of GCTC in both White and Black men increased significantly with distance from the equator, approximately 1% per degree within the range of latitudes studied.

Is yolk sac tumor related to the pathophysiology of low birthweight?

An 8-year-old Japanese girl was admitted with an ovarian yolk sac tumor. Regarding birth history, the patient had been delivered by cesarean section at 25 weeks of gestation with a birthweight of 711g. She had required neonatal intensive care including oxygenation, various medications, and tests. After surgery and chemotherapy, there was no recurrence for 2 years, at the time of writing. Yolk sac tumor, which is a malignant germ cell tumor, is rare in children. Although the cause and risk factors are unclear, it has been reported that malignant germ cell tumors in childhood have been associated with pathophysiology at birth. Given that premature infants are more likely to survive due to advances in perinatal care, it is expected that such cases will increase in the near future. We suggest that children born prematurely require careful follow up.

Planned Repeat Cesarean Section at Term and Adverse Childhood Health Outcomes: A Record-Linkage Study

BACKGROUND

Global cesarean section (CS) rates range from 1% to 52%, with a previous CS being the commonest indication. Labour following a previous CS carries risk of scar rupture, with potential for offspring hypoxic brain injury, leading to high rates of repeat elective CS. However, the effect of delivery by CS on long-term outcomes in children is unclear. Increasing evidence suggests that in avoiding exposure to maternal bowel flora during labour or vaginal birth, offspring delivered by CS may be adversely affected in terms of energy uptake from the gut and immune development, increasing obesity and asthma risks, respectively. This study aimed to address the evidence gap on long-term childhood outcomes following repeat CS by comparing adverse childhood health outcomes after (1) planned repeat CS and (2) unscheduled repeat CS with those that follow vaginal birth after CS (VBAC).

METHODS AND FINDINGS

A data-linkage cohort study was performed. All second-born, term, singleton offspring delivered between 1 January 1993 and 31 December 2007 in Scotland, UK, to women with a history of CS (n = 40,145) were followed up until 31 January 2015. Outcomes assessed included obesity at age 5 y, hospitalisation with asthma, learning disability, cerebral palsy, and death. Cox regression and binary logistic regression were used as appropriate to compare outcomes following planned repeat CS (n = 17,919) and unscheduled repeat CS (n = 8,847) with those following VBAC (n = 13,379). Risk of hospitalisation with asthma was greater following both unscheduled repeat CS (3.7% versus 3.3%, adjusted hazard ratio [HR] 1.18, 95% CI 1.05-1.33) and planned repeat CS (3.6% versus 3.3%, adjusted HR 1.24, 95% CI 1.09-1.42) compared with VBAC. Learning disability and death were more common following unscheduled repeat CS compared with VBAC (3.7% versus 2.3%, adjusted odds ratio 1.64, 95% CI 1.17-2.29, and 0.5% versus 0.4%, adjusted HR 1.50, 95% CI 1.00-2.25, respectively). Risk of obesity at age 5 y and risk of cerebral palsy were similar between planned repeat CS or unscheduled repeat CS and VBAC. Study limitations include the risk that women undergoing an unscheduled CS had intended to have a planned CS, and lack of data on indication for CS, which may confound the findings.

CONCLUSIONS

Birth by repeat CS, whether planned or unscheduled, was associated with an increased risk of hospitalisation with asthma but no difference in risk of obesity at age 5 y. Greater risk of death and learning disability following unscheduled repeat CS compared to VBAC may reflect complications during labour. Further research, including meta-analyses of studies of rarer outcomes (e.g., cerebral palsy), are needed to confirm whether such risks are similar between delivery groups.

Exposure to polychlorinated biphenyls and hexachlorobenzene, semen quality and testicular cancer risk

PURPOSE

We carried out a case-control study to investigate the possible role of occupational and environmental exposure to endocrine disruptors in the onset of testicular cancer (TC).

METHODS

We evaluated 125 TC patients and 103 controls. Seminal fluid examination and organochlorine analysis were performed in all subjects. Cases and controls were also interviewed using a structured questionnaire to collect demographic information, residence, andrological medical history and dietary information.

RESULTS

We found that a higher level of reproductive tract birth defects was associated with a higher risk of TC. With regard to diet, cases reported a higher consumption of milk and dairy products than controls. Overall, there was a statistically significant increase in TC risk in cases with detectable values of total polychlorinated organic compounds against controls (14.4 vs. 1.0 %; p < 0.001). TC patients with detectable levels of organochlorines had lower mean semen parameters than those with undetectable levels, although this difference was not statistically significant.

CONCLUSION

The International Agency for Research on Cancer recently included dioxin-like polychlorinated biphenyls (PCBs) in Group 1 of known human carcinogens. Our study confirmed and identified various risk factors for testicular cancer: cryptorchidism, consumption of milk and dairy products, parents' occupation and serum concentration of hexachlorobenzene and PCBs and, for the first time, we showed the correlation between semen quality and the serum concentration of these pollutants.

Cesarean delivery and hematopoietic stem cell epigenetics in the newborn infant: implications for future health?

OBJECTIVE

Cesarean section (CS) has been associated with a greater risk for asthma, diabetes, and cancer later in life. Although elective CS continues to rise, it is unclear whether and how it may contribute to compromised future health. Our aim was to investigate the influence of mode of delivery on the epigenetic state in neonatal hematopoietic stem cells.

STUDY DESIGN

This was an observational study of 64 healthy, singleton, newborn infants (33 boys) born at term. Cord blood was sampled after elective CS (n = 27) and vaginal delivery. Global deoxyribonucleic acid (DNA) methylation in hematopoietic stem cells (CD34+) was determined by luminometric methylation assay, and genome-wide, locus-specific DNA methylation analysis was performed by Illumina Infinium 450K (Illumina, San Diego, CA), validated by bisulfite-pyrosequencing.

RESULTS

CD34+ cells from infants delivered by CS were globally more DNA methylated (+2%) than DNA from infants delivered vaginally (P = .02). In relation to mode of delivery, a locus-specific analysis identified 343 loci with a difference in DNA methylation of 10% or greater (P < .01). A majority of the differentially methylated loci in neonatal CD34+ cells (76%) were found to be hypermethylated after vaginal delivery. In these infants, the degree of DNA methylation in 3 loci correlated to the duration of labor. The functional relevance of differentially methylated loci involved processes such as immunoglobulin biosynthetic process, regulation of glycolysis and ketone metabolism, and regulation of the response to food.

CONCLUSION

A possible interpretation is that mode of delivery affects the epigenetic state of neonatal hematopoietic stem cells. Given the functional relevance indicated, our findings may have important implications for health and disease in later life.

Global and single gene DNA methylation in umbilical cord blood cells after elective caesarean: a pilot study

OBJECTIVE

To evaluate global and single gene methylation patterns as a sign for epigenetic modulation of the immune system in infants born by elective cesarean section (CS) and vaginal delivery (VD).

STUDY DESIGN

For this prospective pilot study a two step approach was chosen. Initially 41 newborn infants comprising 23 delivered by VD and 18 delivered by elective CS were included. Global DNA methylation of umbilical cord blood was determined. In a second step, methylation status of 96 single genes linked to T cell activation, cytokine production, inflammatory response, and stem cell transcription was evaluated in 48 newborn infants, 20 delivered by VD and 28 delivered by CS.

RESULTS

Global methylation did not differ significantly between CS and VD (p=0.732). The methylation status was low (threshold: ≤3%) for the majority of single genes (n=92) in both groups. FOXP3, CD7, ELA2, and IRF1 showed hypermethylation in both groups. In the CS group, ELA2 (p<0.001) and IRF1(p =0.017) showed significantly higher methylation compared to the VD group.

CONCLUSION

We found no difference in global methylation between newborn infants in the VD group compared to the elective CS group. Methylation of single genes was significantly higher in newborn infants delivered by elective CS. Further research is needed to determine the significance of theses findings.

Testicular cancer incidence to rise by 25% by 2025 in Europe? Model-based predictions in 40 countries using population-based registry data

BACKGROUND

Testicular cancer mainly affects White Caucasian populations, accounts for 1% of all male cancers, and is frequently the most common malignancy among young adult men. In light of the escalating rates of testicular cancer incidence in Europe, and in support of future planning to ensure optimal care of patients with what can be a curable disease, we predict the future burden in 40 European countries around 2025.

METHODS

Current observed trends were extrapolated with the NORDPRED model to estimate the future burden of testicular cancer in the context of changes in risk versus changes in demographics.

FINDINGS

Despite substantial heterogeneity in the rates, the vast majority of European countries will see an increasing burden over the next two decades. We estimate there will be 23,000 new cases of testicular cancer annually in Europe by 2025, a rise of 24% from 2005. Some of the most rapid increases in testicular cancer are observed in Croatia, Slovenia, Italy and Spain, and a transition is underway, whereby recent attenuations and declines in rates in certain high-risk countries in Northern Europe contrast with the increasing trends and escalating burden in Southern Europe. According to our estimates for 2025, around one in 100 men will be diagnosed with the disease annually in the highest risk countries of Europe (Croatia, Slovenia and Norway).

INTERPRETATION

Elucidating the key determinants of testicular cancer and the equitable provision of optimal care for patients across Europe are priorities given the steady rise in the number of patients by 2025, and an absence of primary prevention opportunities.

FUNDING

None.

Evidence for sexually dimorphic associations between maternal characteristics and anogenital distance, a marker of reproductive development

Data from animal models, historical cohorts, and modern epidemiologic studies have suggested that maternal characteristics can affect reproductive health of offspring; however, distinguishing between prenatal and postnatal contributions is difficult. Anogenital distance (AGD), the distance from the anus to the genitals, is believed to be a biomarker of prenatal androgen exposure in many species, and in humans it has been associated with several adult reproductive health outcomes. We used data from a pregnancy cohort study conducted in 4 US cities from 1999-2005 to examine whether AGD measurements in infants were associated with maternal self-reported age at conception, age at menarche, age at first birth, parity, and gravidity. AGD was measured in 289 infants (140 male, 149 female) born to study participants. After adjustment for relevant covariates, in linear regression models stratified by infant sex, maternal age was positively associated with AGD in male infants (AGD, anus to penis: β = 0.50, P = 0.002; AGD, anus to scrotum: β = 0.29, P = 0.02) but not female infants. Parity was inversely associated with AGD (anus to scrotum; β = -1.68, P = 0.03) in male infants. No other maternal characteristic predicted AGD in either sex. The mechanism underlying the unexpected relationship between maternal characteristics and AGD is unknown; however, we suggest several possibilities for future study.

An overview of epigenetics in nursing

Epigenetic changes to the genome are biochemical alterations to the DNA that do not change an individual's genome but do change and influence gene expression. The nursing profession is qualified to conduct and integrate epigenetic-focused nursing research into practice. This article discusses current epigenetic nursing research, provides an overview of how epigenetic research relates to nursing practice, makes recommendations, and provides epigenetic online resources for nursing research. An overview of major epigenetic studies in nursing (specific to childbirth studies, preeclampsia, metabolic syndrome, immunotherapy cancer, and pain) is provided, with recommendations on next steps.

Molecular characteristics of malignant ovarian germ cell tumors and comparison with testicular counterparts: implications for pathogenesis

This review focuses on the molecular characteristics and development of rare malignant ovarian germ cell tumors (mOGCTs). We provide an overview of the genomic aberrations assessed by ploidy, cytogenetic banding, and comparative genomic hybridization. We summarize and discuss the transcriptome profiles of mRNA and microRNA (miRNA), and biomarkers (DNA methylation, gene mutation, individual protein expression) for each mOGCT histological subtype. Parallels between the origin of mOGCT and their male counterpart testicular GCT (TGCT) are discussed from the perspective of germ cell development, endocrinological influences, and pathogenesis, as is the GCT origin in patients with disorders of sex development. Integrated molecular profiles of the 3 main histological subtypes, dysgerminoma (DG), yolk sac tumor (YST), and immature teratoma (IT), are presented. DGs show genomic aberrations comparable to TGCT. In contrast, the genome profiles of YST and IT are different both from each other and from DG/TGCT. Differences between DG and YST are underlined by their miRNA/mRNA expression patterns, suggesting preferential involvement of the WNT/β-catenin and TGF-β/bone morphogenetic protein signaling pathways among YSTs. Characteristic protein expression patterns are observed in DG, YST and IT. We propose that mOGCT develop through different developmental pathways, including one that is likely shared with TGCT and involves insufficient sexual differentiation of the germ cell niche. The molecular features of the mOGCTs underline their similarity to pluripotent precursor cells (primordial germ cells, PGCs) and other stem cells. This similarity combined with the process of ovary development, explain why mOGCTs present so early in life, and with greater histological complexity, than most somatic solid tumors.

The EPIIC hypothesis: intrapartum effects on the neonatal epigenome and consequent health outcomes

There are many published studies about the epigenetic effects of the prenatal and infant periods on health outcomes. However, there is very little knowledge regarding the effects of the intrapartum period (labor and birth) on health and epigenetic remodeling. Although the intrapartum period is relatively short compared to the complete perinatal period, there is emerging evidence that this time frame may be a critical formative phase for the human genome. Given the debates from the National Institutes of Health and World Health Organization regarding routine childbirth procedures, it is essential to establish the state of the science concerning normal intrapartum epigenetic physiology. EPIIC (Epigenetic Impact of Childbirth) is an international, interdisciplinary research collaboration with expertise in the fields of genetics, physiology, developmental biology, epidemiology, medicine, midwifery, and nursing. We hypothesize that events during the intrapartum period - specifically the use of synthetic oxytocin, antibiotics, and cesarean section - affect the epigenetic remodeling processes and subsequent health of the mother and offspring. The rationale for this hypothesis is based on recent evidence and current best practice.

Cesarean section and development of the immune system in the offspring

This review examines the relation between the mode of delivery and development of the immune system in the offspring. Recent epidemiological studies provide evidence that elective cesarean section (CS) is associated with aberrant short-term immune responses in the newborn infant, and a greater risk of developing immune diseases such as asthma, allergies, type 1 diabetes, and celiac disease. However, it is still unknown whether CS causes a long-term effect on the immune system of the offspring that contributes to compromised immune health. With the dramatic increase in the rate of CS today, a greater emphasis should be placed on the discussion among both professionals and childbearing women on potential consequences of CS on the health of the offspring.

The long-term effects of birth by caesarean section: the case for a randomised controlled trial

Birth by caesarean section is rising rapidly around the world and is associated with a range of adverse short and long-term outcomes in offspring. The latter include features of the metabolic syndrome, type-1 diabetes, and asthma. Though there are several plausible candidate biological mechanisms, evidence of a causal relationship between mode of delivery and long-term outcomes remains lacking. Here we review the evidence to date, and examine ways in which future studies might advance understanding. We conclude that a randomised controlled trial of mode of delivery for the healthy term, cephalic pregnancy, is neither unethical nor unfeasible and should be seriously considered as the optimum means of addressing a question of great relevance to public health.

Cesarean section and offspring's risk of inflammatory bowel disease: a national cohort study

BACKGROUND

Intestinal bacteria have been implicated in the etiology of the common inflammatory bowel diseases (IBD) ulcerative colitis and Crohn's disease. Because delivery by cesarean section disturbs the normal bacterial colonization of the newborn's intestine, we determined the risk of IBD according to mode of delivery.

METHODS

A register-based national cohort study of 2.1 million Danes born 1973-2008. The effect of mode of delivery on IBD incidence in the age-span 0-35 years was estimated by means of confounder-adjusted incidence rate ratios (IRRs) with 95% confidence intervals (CIs) obtained in Poisson regression analysis. Information on mode of delivery was obtained from the Danish Medical Birth Registry and cases of IBD were identified in the Danish National Patient Registry 1977-2008.

RESULTS

During 32.6 million person-years of follow-up, a total of 8142 persons were diagnosed with IBD before age 36 years. Cesarean section was associated with moderately, yet significantly, increased risk of IBD at age 0-14 years (IRR 1.29, 95% CI 1.11-1.49), regardless of parental disposition to IBD. Assuming causality, an estimated 3.2% of IBD cases before age 15 years were attributable to cesarean section.

CONCLUSIONS

Rates of IBD with onset in childhood are moderately increased after birth by cesarean section but underlying mechanisms remain unclear. Even if the association is causal, the possible impact of increasing cesarean section practices on the overall burden of IBD in childhood is small.

Caesarean section: impact on mother and child

Maternal/foetal morbidity/mortality consequent to uterine rupture, placenta previa/increta and stillbirth may occur in repeat caesarean section (CS). Elective CS before 39 weeks increases respiratory complications, hypoglycaemia, sepsis and intensive care unit admissions. Different gut colonization in neonates born by CS accounts for increased incidence of food allergy, asthma and possibly type 1 diabetes. Epigenetic changes might be responsible - among others - for childhood malignancies.

CONCLUSION

Decision for primary CS should take into consideration possible maternal/neonatal complications.

Gestational age at birth and risk of testicular cancer

Most testicular germ cell tumors originate from carcinoma in situ cells in fetal life, possibly related to sex hormone imbalances in early pregnancy. Previous studies of association between gestational age at birth and testicular cancer have yielded discrepant results and have not examined extreme preterm birth. Our objective was to determine whether low gestational age at birth is independently associated with testicular cancer in later life. We conducted a national cohort study of 354,860 men born in Sweden in 1973-1979, including 19,214 born preterm (gestational age < 37 weeks) of whom 1,279 were born extremely preterm (22-29 weeks), followed for testicular cancer incidence through 2008. A total of 767 testicular cancers (296 seminomas and 471 nonseminomatous germ cell tumors) were identified in 11.2 million person-years of follow-up. Extreme preterm birth was associated with an increased risk of testicular cancer (hazard ratio = 3.95; 95% confidence interval = 1.67-9.34) after adjusting for other perinatal factors, family history of testicular cancer and cryptorchidism. Only five cases (three seminomas and two nonseminomas) occurred among men born extremely preterm, limiting the precision of risk estimates. No association was found between later preterm birth, post-term birth or low or high fetal growth and testicular cancer. These findings suggest that extreme but not later preterm birth may be independently associated with testicular cancer in later life. They are based on a small number of cases and will need confirmation in other large cohorts. Elucidation of the key prenatal etiologic factors may potentially lead to preventive interventions in early life.

Birth order and risk of childhood cancer: a pooled analysis from five US States

The causes of childhood cancers are largely unknown. Birth order has been used as a proxy for prenatal and postnatal exposures, such as frequency of infections and in utero hormone exposures. We investigated the association between birth order and childhood cancers in a pooled case-control dataset. The subjects were drawn from population-based registries of cancers and births in California, Minnesota, New York, Texas and Washington. We included 17,672 cases <15 years of age who were diagnosed from 1980 to 2004 and 57,966 randomly selected controls born 1970-2004, excluding children with Down syndrome. We calculated odds ratios and 95% confidence intervals using logistic regression, adjusted for sex, birth year, maternal race, maternal age, multiple birth, gestational age and birth weight. Overall, we found an inverse relationship between childhood cancer risk and birth order. For children in the fourth or higher birth order category compared to first-born children, the adjusted OR was 0.87 (95% CI: 0.81, 0.93) for all cancers combined. When we examined risks by cancer type, a decreasing risk with increasing birth order was seen in the central nervous system tumors, neuroblastoma, bilateral retinoblastoma, Wilms tumor and rhabdomyosarcoma. We observed increased risks with increasing birth order for acute myeloid leukemia but a slight decrease in risk for acute lymphoid leukemia. These risk estimates were based on a very large sample size, which allowed us to examine rare cancer types with greater statistical power than in most previous studies, however the biologic mechanisms remain to be elucidated.

A systematic review and meta-analysis of perinatal variables in relation to the risk of testicular cancer--experiences of the son

BACKGROUND

We undertook a systematic review and meta-analysis of perinatal variables in relation to testicular cancer risk, with a specific focus upon characteristics of the son.

METHODS

Literature databases Scopus, EMBASE, PubMed and Web of Science were searched using highly sensitive search strategies. Of 5865 references retrieved, 67 articles met the inclusion criteria, each of which was included in at least one perinatal analysis.

RESULTS

Random effects meta-analysis produced the following results for association with testicular cancer risk: birth weight [per kilogram, odds ratio (OR) = 0.94, 95% confidence interval (CI) 0.88-1.01, I(2)= 12%], low birth weight (OR = 1.34, 95% CI 1.08-1.67, I(2)= 51%), high birth weight (OR = 1.05, 95% CI 0.96-1.14, I(2)= 0%), gestational age (per week, OR = 0.95, 95% CI 0.92-0.98, I(2)= 38%; low vs not, OR = 1.31, 95% CI 1.07-1.59, I(2)= 49%), cryptorchidism (OR = 4.30, 95% CI 3.62-5.11, I(2)= 44%), inguinal hernia (OR = 1.63, 95% CI 1.37-1.94, I(2)= 38%) and twinning (OR = 1.22, 95% CI 1.03-1.44, I(2)= 22%). Meta-analyses of the variables birth length, breastfeeding and neonatal jaundice did not provide evidence for an association with testicular cancer risk. When low birth weight was stratified by data ascertainment (record/registry vs self-report), only the category of self-report was indicative of an association. Meta-regression of data ascertainment (record/registry vs self-report) inferred that record-/registry-based studies were less supportive of an association with gestational age (per week = 0.97, 95% CI 0.94-1.00, I(2)( )= 29%; low vs not = 1.08, 95% CI 0.91-1.28, I(2)= 32%).

CONCLUSION

In conclusion, this systematic review and meta-analysis finds evidence that cryptorchidism, inguinal hernia and twinning, and tentative evidence that birth weight and gestational age, are associated with risk of testicular cancer.

Gonadal tumours and DSD

Disorders of sex development (DSD), previously referred to as intersex, has been recognised as one of the main risk factors for development of type II germ cell tumours (GCTs), that is, seminomas/dysgerminomas and non-seminomas (e.g., embryonal carcinoma, yolk sac tumour, choriocarcinoma and teratoma). Within the testis, this type of cancer is the most frequent malignancy in adolescent and young adult Caucasian males. Although these males are not known to have dysgenetic gonads, the similarities in the resulting tumours suggest a common aetiological mechanism(s),--genetically, environmentally or a combination of both. Within the group of DSD patients, being in fact congenital conditions, the risk of malignant transformation of germ cells is highly heterogeneous, depending on a number of parameters, some of which have only recently been identified. Understanding of these recent insights will stimulate further research, with the final aim to develop an informative clinical decision tree for DSD patients, which includes optimal (early) diagnosis without overtreatment, such as prophylactic gonadectomy in the case of a low tumour risk.

Etiologic factors in testicular germ-cell tumors

Globally, testicular cancer incidence is highest among men of northern European ancestry and lowest among men of Asian and African descent. Incidence rates have been increasing around the world for at least 50 years, but mortality rates, at least in developed countries, have been declining. While reasons for the decreases in mortality are related to improvements in therapeutic regimens introduced in the late 1970s, reasons for the increase in incidence are less well understood. However, an accumulating body of evidence suggests that testicular cancer arises in fetal life. Perinatal factors, including exposure to endocrine-disrupting chemicals, have been suggested to be related to risk.

A systematic review and meta-analysis of perinatal variables in relation to the risk of testicular cancer--experiences of the mother

BACKGROUND

We undertook a systematic review and meta-analysis of perinatal variables in relation to testicular cancer risk, with a specific focus upon characteristics of the mother.

METHODS

EMBASE, PubMed, Scopus and Web of Science databases were searched using sensitive search strategies. Meta-analysis was undertaken using STATA 10.

RESULTS

A total of 5865 references were retrieved, of which 67 met the inclusion criteria and contributed data to at least one perinatal analysis. Random effects meta-analysis found maternal bleeding during pregnancy [odds ratio (OR) 1.33, 95% confidence interval (CI) 1.02-1.73], birth order (primiparous vs not, 1.08, 95% CI 1.01-1.16; second vs first, OR 0.94, 95% CI 0.88-0.99; third vs first, OR 0.91, 95% CI 0.83-1.01; fourth vs first, OR 0.80, 95% CI 0.69-0.94) and sibship size (2 vs 1, OR 0.93, 95% CI 0.75-1.15; 3 vs 1, OR 0.89, 95% CI 0.74-1.07; 4 vs 1, OR 0.75, 95% CI 0.62-0.90) to be associated with testicular cancer risk. Meta-analyses that produced summary estimates which indicated no association included maternal age, maternal nausea, maternal hypertension, pre-eclampsia, breech delivery and caesarean section. Meta-regression provided evidence that continent of study is important in the relationship between caesarean section and testicular cancer (P = 0.035), and a meta-analysis restricted to the three studies from the USA was suggestive of association (OR 1.67, 95% CI 1.07-2.56).

CONCLUSIONS

This systematic review and meta-analysis has found evidence for associations of maternal bleeding, birth order, sibship size and possibly caesarean section with risk of testicular cancer.

Epigenetic modulation at birth - altered DNA-methylation in white blood cells after Caesarean section

AIM

Delivery by C-section (CS) has been associated with increased risk for allergy, diabetes and leukaemia. Whereas the underlying cause is unknown, epigenetic change of the genome has been suggested as a candidate molecular mechanism for perinatal contributions to later disease risk. We hypothesized that mode of delivery affects epigenetic activity in newborn infants.

METHODS

A total of 37 newborn infants were included. Spontaneous vaginal delivery (VD) occurred in 21, and 16 infants were delivered by elective CS. Blood was sampled from the umbilical cord and 3-5 days after birth. DNA-methylation was analyzed in leucocytes.

RESULTS

Infants born by CS exhibited higher DNA-methylation in leucocytes compared with that of those born by VD (p < 0.001). After VD, newborn infants exhibited stable levels of DNA-methylation, as evidenced by comparing cord blood values with those 3-5 days after birth (p = 0.55). On postnatal days 3-5, DNA-methylation had decreased in the CS group (p = 0.01) and was no longer significantly different from that of VD (p = 0.10).

CONCLUSION

DNA-methylation is higher in infants delivered by CS than in infants vaginally born. Although currently unknown how gene expression is affected, or whether epigenetic differences related to mode of delivery are long-lasting, our findings open a new area of clinical research with potentially important public health implications.

Human testicular (non)seminomatous germ cell tumours: the clinical implications of recent pathobiological insights

Human germ cell tumours (GCTs) comprise several types of neoplasias with different pathogeneses and clinical behaviours. A classification into five subtypes has been proposed. Here, the so-called type II testicular GCTs (TGCTs), ie the seminomas and non-seminomas, will be reviewed with emphasis on pathogenesis and clinical implications. Various risk factors have been identified that define subpopulations of men who are amenable to early diagnosis. TGCTs are omnipotent, able to generate all differentiation lineages, both embryonic and extra-embryonic, as well as the germ cell lineage itself. The precursor lesion, composed of primordial germ cells/gonocytes, is referred to as carcinoma in situ of the testis (CIS) and gonadoblastoma of the dysgenetic gonad. These pre-malignant cells retain embryonic characteristics, which probably explains the unique responsiveness of the derived tumours to DNA-damaging agents. Development of CIS and gonadoblastoma is crucially dependent on the micro-environment created by Sertoli cells in the testis, and granulosa cells in the dysgenetic gonad. OCT3/4 has high sensitivity and specificity for CIS/gonadoblastoma, seminoma, and embryonal carcinoma, and is useful for the detection of CIS cells in semen, thus a promising tool for non-invasive screening. Overdiagnosis of CIS due to germ cell maturation delay can be avoided using immunohistochemical detection of stem cell factor (SCF). Immunohistochemistry is helpful in making the distinction between seminoma and embryonal carcinoma, especially SOX17 and SOX2. The different non-seminomatous histological elements can be recognized using various markers, such as AFP and hCG, while others need confirmation. The value of micro-satellite instability as well as BRAF mutations in predicting treatment resistance needs validation in prospective trials. The availability of representative cell lines, both for seminoma and for embryonal carcinoma, allows mechanistic studies into the initiation and progression of this disease.

Gestational hypertension, preeclampsia, and risk of testicular cancer

Altered levels of pregnancy hormones have been suggested to initiate testicular cancer prenatally in the male fetus. The placenta is the main source of pregnancy hormones, and pregnancy hypertension and preeclampsia are associated with placental malfunction, including altered levels of hormones such as estrogen and human chorionic gonadotropin. We therefore evaluated fetal exposure to pregnancy hypertension and preeclampsia in relation to risk of testicular cancer in adolescent and adult life. We identified 293 cases of germ cell testicular cancer in the Swedish Cancer Register, and 861 controls in the Swedish Medical Birth Register. The standardized antenatal and delivery charts of the cases and controls were traced in the archives of the delivery units, and information about maternal and pregnancy characteristics such as gestational hypertension, proteinuria, anemia, and glucosuria were extracted. Odds ratios (OR) with 95% confidence intervals (CI) were calculated using conditional logistic regression. We found a strongly decreased risk of testicular cancer among subjects exposed to severe gestational hypertension (OR, 0.29; 95% CI, 0.12-0.74, compared with no hypertension), whereas the risk was increased among those exposed to mild gestational hypertension (OR, 1.62; 95% CI, 0.98-2.69) during the fetal period. The mechanism behind the association between pregnancy hypertension and testicular cancer is unclear, but our findings may reflect a potentially protective effect of the altered pregnancy hormones such as human chorionic gonadotropin that occur in severe gestational hypertension and preeclampsia.